All those graphs looks great. I love the numbers you can up with. I do think you can make a much more simple design and achieve...
All those graphs looks great. I love the numbers you can up with. I do think you can make a much more simple design and achieve something very similar but much more simplicity.
I feel like the rear end could have some major issues with flex also loading all the bearings in a turn with how you have it, could cause binding.
Yeah, I was thinking it could be pretty heavy, due to the size of the two links, and then the extra links, I think it'll be worth mocking up in CAD. I've been working on another design that is giving the same numbers, but with a lot fewer links. It's not quite the same, but I can upload that one too with its kinematics graphs.
Having a few more minutes, the link I gave above does cover it, but I think the PB variant is even clearer:
https://www.pinkbike.com/news/definitions-what-is-anti-squat.html
It explains how...
It explains how to map out antisquat (depending on where in the travel you are of course, as it's not static), but the TL;DR is, the higher the pivot point,t he more geometric antisquat you have, which is then refined by the amount the chain grows going through the travel to get the final antisquat value - a high pivot bike without an idler will have A LOT of antisquat. A low pivot bike with a high mounted idler will have very low antisquat numbers (effectively pro-squat if the chain is routed above the line from the rear axle to the pivot point).
As for your design, first, you're in the i-Track patent area (idler on a moveable link that is not the swingarm). Second, what is the distance between the two main pivots, centre to centre? When designing bikes clicking around in Linkage is all fine and dandy, but will you be able to package it all together? Or will it require 10 mm outer diameter bearings with very thin walls to make it work which will require 5 mm thick axles and thin section bearings that will all explode the first time you sit on it?
Doing the math the center to center distance between the two pivot points is about 30.9 mm. It is very tight, but I think that an...
Doing the math the center to center distance between the two pivot points is about 30.9 mm. It is very tight, but I think that an appropriatly sized bearing would fit in the space. This is why I posted it here, to have more eyes on it while I am experimenting and people to bring up things I may not have thought about. The I-Track pattents weren't something that I was aware of either, and that will be important to keep in mind. I wouldn't want to develop an idea to find out that parts of the design are pattented by someone else far down the line.
Like @earleb said it's not an issue if you don't sell it, but still, maybe something to keep in mind.
30,9 mm gives you enough space...
Like @earleb said it's not an issue if you don't sell it, but still, maybe something to keep in mind.
30,9 mm gives you enough space to use two 28 mm OD bearings with a 1 mm wall on the link and 0,9 mm clearance between them to over all the tolerances and have some gap. Frames are trending towards 20+ mm ID bearings lately for the main pivots, you can imagine what that means for the OD. Santa Cruz is using 6902 bearing (15x28x7 mm) in their lower link for the Hightower, Megatower & co which would leave you a 1 mm wall thickness around the bearing. This is way too thin even for something like steel, let alone aluminium.
You are of course free to try it, but if you have a look at what bearings most bikes use you will at least get a feeling for the size needed.
Absolutely, and larger bearings usually run a bit smoother and last longer. It's definitely something to consider. I think my current bike, a last gen Norco Sight, is using a 30 mm OD bearing for its main pivot, but compared to something like the Raaw Madonna, even that is tiny. I'm wanting to keep manufacturing and end user service in mind when working on these ideas, and if I can have larger bearings and fewer of them and get mostly the same results, that would be better. I eventually do want to sell the bikes I design, so keeping patents in mind will be important for me. The I Track one is a little irritating though haha. I took a look at the filing and it looks like they patented almost every pattern of suspension with the idler wheel on a link instead of the main frame or pivot that they could think of.
All those graphs looks great. I love the numbers you can up with. I do think you can make a much more simple design and achieve...
All those graphs looks great. I love the numbers you can up with. I do think you can make a much more simple design and achieve something very similar but much more simplicity.
I feel like the rear end could have some major issues with flex also loading all the bearings in a turn with how you have it, could cause binding.
Yeah, I was thinking it could be pretty heavy, due to the size of the two links, and then the extra links, I think it'll be...
Yeah, I was thinking it could be pretty heavy, due to the size of the two links, and then the extra links, I think it'll be worth mocking up in CAD. I've been working on another design that is giving the same numbers, but with a lot fewer links. It's not quite the same, but I can upload that one too with its kinematics graphs.
Here is the simpler version, it's not quite the same but it is pretty close and only uses two links.
All those graphs looks great. I love the numbers you can up with. I do think you can make a much more simple design and achieve...
All those graphs looks great. I love the numbers you can up with. I do think you can make a much more simple design and achieve something very similar but much more simplicity.
I feel like the rear end could have some major issues with flex also loading all the bearings in a turn with how you have it, could cause binding.
Yeah, I was thinking it could be pretty heavy, due to the size of the two links, and then the extra links, I think it'll be...
Yeah, I was thinking it could be pretty heavy, due to the size of the two links, and then the extra links, I think it'll be worth mocking up in CAD. I've been working on another design that is giving the same numbers, but with a lot fewer links. It's not quite the same, but I can upload that one too with its kinematics graphs.
Here is the simpler version, it's not quite the same but it is pretty close and only uses two links.
Here is the simpler version, it's not quite the same but it is pretty close and only uses two links.
I guess I just wonder what your goal is.
That leverage ratio looks very different, Anti-rise is pretty different. Also axle path slightly changed and migration of the instant center is opposite. I understand you are messing around and seeing what works.
Yeah, I was thinking it could be pretty heavy, due to the size of the two links, and then the extra links, I think it'll be...
Yeah, I was thinking it could be pretty heavy, due to the size of the two links, and then the extra links, I think it'll be worth mocking up in CAD. I've been working on another design that is giving the same numbers, but with a lot fewer links. It's not quite the same, but I can upload that one too with its kinematics graphs.
I guess I just wonder what your goal is.
That leverage ratio looks very different, Anti-rise is pretty different. Also axle path slightly changed and migration...
I guess I just wonder what your goal is.
That leverage ratio looks very different, Anti-rise is pretty different. Also axle path slightly changed and migration of the instant center is opposite. I understand you are messing around and seeing what works.
Just need to figure out what is important to you.
You're right about that. I'm not sure if I fully understand what is important to me right now, so I'm throwing things at the wall to see what sticks. I know what axle path I want (mostly vertical, slightly rearward), about what progression I want ( about 25%, so you can run air and coil shocks easily and I don't want it to feel like you hit a wall of progression), and I want it to be able to pedal pretty efficiently, so that means anti squat values above at or above 100% at sag. The movement of the IC isn't as important to me, so long as the axle path is right. Then, after that, I want it to not be too heavy. Looking at bikes that I have loved before, 2016 Trek Remedy, Ibis Mojo SL, 2021 Niner Rip 9, every Kona process, V2 Santa Cruz Nomad, 2012 Yeti SB66, their kinematics have been all over the place. I personally don't care about complexity, or the number of bearings, six bar links and having 12 bearings doesn't put me off, but more complex links add weight, and I do want to produce my designs to sell eventually. I also have a desire for the layout to be bespoke, something different that stands out, not just another four bar with rocker link, that make up so much of the market right now. Both of the designs that I've put together so far, while different, do hit on the points that I think I want, but the first one is more appealing to me personally since it is more unique, even if that comes with it's own issues, like the size of the bearings in the main pivots, or flex and weight.
I guess I just wonder what your goal is.
That leverage ratio looks very different, Anti-rise is pretty different. Also axle path slightly changed and migration...
I guess I just wonder what your goal is.
That leverage ratio looks very different, Anti-rise is pretty different. Also axle path slightly changed and migration of the instant center is opposite. I understand you are messing around and seeing what works.
You're right about that. I'm not sure if I fully understand what is important to me right now, so I'm throwing things at the wall to...
You're right about that. I'm not sure if I fully understand what is important to me right now, so I'm throwing things at the wall to see what sticks. I know what axle path I want (mostly vertical, slightly rearward), about what progression I want ( about 25%, so you can run air and coil shocks easily and I don't want it to feel like you hit a wall of progression), and I want it to be able to pedal pretty efficiently, so that means anti squat values above at or above 100% at sag. The movement of the IC isn't as important to me, so long as the axle path is right. Then, after that, I want it to not be too heavy. Looking at bikes that I have loved before, 2016 Trek Remedy, Ibis Mojo SL, 2021 Niner Rip 9, every Kona process, V2 Santa Cruz Nomad, 2012 Yeti SB66, their kinematics have been all over the place. I personally don't care about complexity, or the number of bearings, six bar links and having 12 bearings doesn't put me off, but more complex links add weight, and I do want to produce my designs to sell eventually. I also have a desire for the layout to be bespoke, something different that stands out, not just another four bar with rocker link, that make up so much of the market right now. Both of the designs that I've put together so far, while different, do hit on the points that I think I want, but the first one is more appealing to me personally since it is more unique, even if that comes with it's own issues, like the size of the bearings in the main pivots, or flex and weight.
Awesome. I was in a similar position as you 2 years ago and was talking with a frame builder about a custom DH bike. Eventually I decided to put my money towards buying and selling multiple frames to test. I learned so much this way to learn what a bike feels like and what it looks like mathematically.
Say, I have “lost” $5,000 over 2 years buying and selling but I’ve been able to own and try 6 different frames. Also getting laps on friends bikes.
It’s much more economical to make sure you test and know what you’d like before producing a $5-$10k frame. Unless you have other ways to make them less expensive.
The best bang for your buck is taking laps on friends bikes and creating or looking up the kinematic. Learn how to feel the difference from the shock and the kinematic.
I guess I just wonder what your goal is.
That leverage ratio looks very different, Anti-rise is pretty different. Also axle path slightly changed and migration...
I guess I just wonder what your goal is.
That leverage ratio looks very different, Anti-rise is pretty different. Also axle path slightly changed and migration of the instant center is opposite. I understand you are messing around and seeing what works.
You're right about that. I'm not sure if I fully understand what is important to me right now, so I'm throwing things at the wall to...
You're right about that. I'm not sure if I fully understand what is important to me right now, so I'm throwing things at the wall to see what sticks. I know what axle path I want (mostly vertical, slightly rearward), about what progression I want ( about 25%, so you can run air and coil shocks easily and I don't want it to feel like you hit a wall of progression), and I want it to be able to pedal pretty efficiently, so that means anti squat values above at or above 100% at sag. The movement of the IC isn't as important to me, so long as the axle path is right. Then, after that, I want it to not be too heavy. Looking at bikes that I have loved before, 2016 Trek Remedy, Ibis Mojo SL, 2021 Niner Rip 9, every Kona process, V2 Santa Cruz Nomad, 2012 Yeti SB66, their kinematics have been all over the place. I personally don't care about complexity, or the number of bearings, six bar links and having 12 bearings doesn't put me off, but more complex links add weight, and I do want to produce my designs to sell eventually. I also have a desire for the layout to be bespoke, something different that stands out, not just another four bar with rocker link, that make up so much of the market right now. Both of the designs that I've put together so far, while different, do hit on the points that I think I want, but the first one is more appealing to me personally since it is more unique, even if that comes with it's own issues, like the size of the bearings in the main pivots, or flex and weight.
Awesome. I was in a similar position as you 2 years ago and was talking with a frame builder about a custom DH bike. Eventually I...
Awesome. I was in a similar position as you 2 years ago and was talking with a frame builder about a custom DH bike. Eventually I decided to put my money towards buying and selling multiple frames to test. I learned so much this way to learn what a bike feels like and what it looks like mathematically.
Say, I have “lost” $5,000 over 2 years buying and selling but I’ve been able to own and try 6 different frames. Also getting laps on friends bikes.
It’s much more economical to make sure you test and know what you’d like before producing a $5-$10k frame. Unless you have other ways to make them less expensive.
The best bang for your buck is taking laps on friends bikes and creating or looking up the kinematic. Learn how to feel the difference from the shock and the kinematic.
I've been thinking about asking to ride some of my friends bikes, just for like a lap or so, to see what I like. Who did you work with when you started manufacturing? I don't want to start throwing money at this until I know more about what may work and what I want, but knowing who might be good to work with now can help me plan.
Doing the math the center to center distance between the two pivot points is about 30.9 mm. It is very tight, but I think that an...
Doing the math the center to center distance between the two pivot points is about 30.9 mm. It is very tight, but I think that an appropriatly sized bearing would fit in the space. This is why I posted it here, to have more eyes on it while I am experimenting and people to bring up things I may not have thought about. The I-Track pattents weren't something that I was aware of either, and that will be important to keep in mind. I wouldn't want to develop an idea to find out that parts of the design are pattented by someone else far down the line.
Like @earleb said it's not an issue if you don't sell it, but still, maybe something to keep in mind.
30,9 mm gives you enough space...
Like @earleb said it's not an issue if you don't sell it, but still, maybe something to keep in mind.
30,9 mm gives you enough space to use two 28 mm OD bearings with a 1 mm wall on the link and 0,9 mm clearance between them to over all the tolerances and have some gap. Frames are trending towards 20+ mm ID bearings lately for the main pivots, you can imagine what that means for the OD. Santa Cruz is using 6902 bearing (15x28x7 mm) in their lower link for the Hightower, Megatower & co which would leave you a 1 mm wall thickness around the bearing. This is way too thin even for something like steel, let alone aluminium.
You are of course free to try it, but if you have a look at what bearings most bikes use you will at least get a feeling for the size needed.
Absolutely, and larger bearings usually run a bit smoother and last longer. It's definitely something to consider. I think my current bike, a last gen Norco...
Absolutely, and larger bearings usually run a bit smoother and last longer. It's definitely something to consider. I think my current bike, a last gen Norco Sight, is using a 30 mm OD bearing for its main pivot, but compared to something like the Raaw Madonna, even that is tiny. I'm wanting to keep manufacturing and end user service in mind when working on these ideas, and if I can have larger bearings and fewer of them and get mostly the same results, that would be better. I eventually do want to sell the bikes I design, so keeping patents in mind will be important for me. The I Track one is a little irritating though haha. I took a look at the filing and it looks like they patented almost every pattern of suspension with the idler wheel on a link instead of the main frame or pivot that they could think of.
Indeed they did. Idler on the front triangle, on the pivot on the front triangle (essentially front triangle) or on the swingarm (single pivot design) is not patented, everything else is.
I did a similar project for my engineering degree about 3 years ago.
I also started out on Linkage, but also started drawing up things in CAD pretty early too. I did mock-ups of phyisical components i had laying around so i could put them in an assembly in CAD, just to check for clearance issues.
The curves you showed look good in general, just bear in mind, if you're going degressivt to linear to progressive as it is the case on the second layout you posted, the bike could feel harsh on impact when landing after a jump.
Oh, another point, with the second design what kind of shock is used ETE and stroke wise? More importantly, it's getting more and more perpendicular going through the travel, which causes very high loads int he top tube - perpendicular loading will try to bend it the most. I still remember Commencal stating they saved I think 150 grams in the downtube alone going from V2 to V3 Supreme by not mounting the shock (perpendicularly) to the downtube. Top tubes are usually even lighter than the downtube and could thus require an even greater difference in weight to gain the strength. Or a brace like Specialized did with the current (outgoing) Stumpjumper - the previous variant apparently kicked back from full travel fairly undamped in the carbon variant as the top tube acted like a bow getting loaded up going through the travel.
If you are not planning to sell bikes you can ignore any patents and build whatever you want for yourself.
Remember a couple of years ago when people on mtbr (I think) started lacing their nylon spokes with a system that closely resembled berd wheels and their legal representative posted that they are not allowed to do so and threatened with legal action if schemes are not taken off... I still don't believe they would actually take the matter to the court but they were super agressive with their response.
You're right about that. I'm not sure if I fully understand what is important to me right now, so I'm throwing things at the wall to...
You're right about that. I'm not sure if I fully understand what is important to me right now, so I'm throwing things at the wall to see what sticks. I know what axle path I want (mostly vertical, slightly rearward), about what progression I want ( about 25%, so you can run air and coil shocks easily and I don't want it to feel like you hit a wall of progression), and I want it to be able to pedal pretty efficiently, so that means anti squat values above at or above 100% at sag. The movement of the IC isn't as important to me, so long as the axle path is right. Then, after that, I want it to not be too heavy. Looking at bikes that I have loved before, 2016 Trek Remedy, Ibis Mojo SL, 2021 Niner Rip 9, every Kona process, V2 Santa Cruz Nomad, 2012 Yeti SB66, their kinematics have been all over the place. I personally don't care about complexity, or the number of bearings, six bar links and having 12 bearings doesn't put me off, but more complex links add weight, and I do want to produce my designs to sell eventually. I also have a desire for the layout to be bespoke, something different that stands out, not just another four bar with rocker link, that make up so much of the market right now. Both of the designs that I've put together so far, while different, do hit on the points that I think I want, but the first one is more appealing to me personally since it is more unique, even if that comes with it's own issues, like the size of the bearings in the main pivots, or flex and weight.
Awesome. I was in a similar position as you 2 years ago and was talking with a frame builder about a custom DH bike. Eventually I...
Awesome. I was in a similar position as you 2 years ago and was talking with a frame builder about a custom DH bike. Eventually I decided to put my money towards buying and selling multiple frames to test. I learned so much this way to learn what a bike feels like and what it looks like mathematically.
Say, I have “lost” $5,000 over 2 years buying and selling but I’ve been able to own and try 6 different frames. Also getting laps on friends bikes.
It’s much more economical to make sure you test and know what you’d like before producing a $5-$10k frame. Unless you have other ways to make them less expensive.
The best bang for your buck is taking laps on friends bikes and creating or looking up the kinematic. Learn how to feel the difference from the shock and the kinematic.
I've been thinking about asking to ride some of my friends bikes, just for like a lap or so, to see what I like. Who did...
I've been thinking about asking to ride some of my friends bikes, just for like a lap or so, to see what I like. Who did you work with when you started manufacturing? I don't want to start throwing money at this until I know more about what may work and what I want, but knowing who might be good to work with now can help me plan.
I worked with Frank The Welder when I was in high school so he was the first one I reached out to. He’s most recently come back into the spot light working with Neko and Frameworks.
But I just completed a steel DH frame project with Adam Prosise who did an incredible job. He’s got an unbelievable attention to detail. Was able to get 3d printed steel parts for my frame also. Instagram- @prosisemetalworks
Oh, another point, with the second design what kind of shock is used ETE and stroke wise? More importantly, it's getting more and more perpendicular going...
Oh, another point, with the second design what kind of shock is used ETE and stroke wise? More importantly, it's getting more and more perpendicular going through the travel, which causes very high loads int he top tube - perpendicular loading will try to bend it the most. I still remember Commencal stating they saved I think 150 grams in the downtube alone going from V2 to V3 Supreme by not mounting the shock (perpendicularly) to the downtube. Top tubes are usually even lighter than the downtube and could thus require an even greater difference in weight to gain the strength. Or a brace like Specialized did with the current (outgoing) Stumpjumper - the previous variant apparently kicked back from full travel fairly undamped in the carbon variant as the top tube acted like a bow getting loaded up going through the travel.
One of the constraints I gave my self was using only readily available shock sizes, so both versions use a 205x60 standard eyelet shock, to give 160ish travel. I can totally see your point about loading the top tube up with the force applied to the shock, causing it to bow and react like a spring itself. That point on the top tube would likely have to be reinforced to keep it from acting like that.
Remember a couple of years ago when people on mtbr (I think) started lacing their nylon spokes with a system that closely resembled berd wheels and...
Remember a couple of years ago when people on mtbr (I think) started lacing their nylon spokes with a system that closely resembled berd wheels and their legal representative posted that they are not allowed to do so and threatened with legal action if schemes are not taken off... I still don't believe they would actually take the matter to the court but they were super agressive with their response.
That's always a good reaction for a company to have, people usually love companies like that...
@Eae903 my two cents on designing suspension when you are currently studying engineering... I know it takes more time, but you have the math background. Try and work out kinematics outside of linkage. You'll learn a ton. Travel is the integral of leverage curve, leverage is the derivative of axle position (usually in the y axis, but leverage curves can be made for any axis). All you really have to do is find axle path and the rest comes easy. It's like how they don't want you to use calculators or computers in math class until you understand the math that's actually being done. Also don't put too much store in things you read on the various MTB websites. Especially on PB I see journalists make a lot of assumptions about how suspension should work that aren't necessarily accurate. For example "while the high overall progression (36%) means things will ramp up quickly in the last 25mm of travel." Sometimes that statement is true, but it is not always true. In fact there are a good number of bikes out there where the ramp up exists primarily in the first part of travel, such as the Ibis Ripmo and Evil Offering.
@Eae903 my two cents on designing suspension when you are currently studying engineering... I know it takes more time, but you have the math background. Try and...
@Eae903 my two cents on designing suspension when you are currently studying engineering... I know it takes more time, but you have the math background. Try and work out kinematics outside of linkage. You'll learn a ton. Travel is the integral of leverage curve, leverage is the derivative of axle position (usually in the y axis, but leverage curves can be made for any axis). All you really have to do is find axle path and the rest comes easy. It's like how they don't want you to use calculators or computers in math class until you understand the math that's actually being done. Also don't put too much store in things you read on the various MTB websites. Especially on PB I see journalists make a lot of assumptions about how suspension should work that aren't necessarily accurate. For example "while the high overall progression (36%) means things will ramp up quickly in the last 25mm of travel." Sometimes that statement is true, but it is not always true. In fact there are a good number of bikes out there where the ramp up exists primarily in the first part of travel, such as the Ibis Ripmo and Evil Offering.
Absolutely, the feeling of the progression, how it ramps, would be dictated by the derivative of the leverage curve, the steeper it gets, the more it feels like it ramps up, or that's at least what my intuition says. Thank you for your advice, it is what I've been wanting to do, but I've never been able to find good information on how to calculate all the values I need to know, and I've been looking for a while. Even the knowledge that leverage is the derivative of the axle path will help me do better work. It's going to take a lot of drafting, but that's why I'm getting solid works installed on my computers and am going to start working in that more. I will, ask, how does a linkage factor in to calculating the leverage? I know you can use them to alter the leverage ratio in any layout.
Absolutely, the feeling of the progression, how it ramps, would be dictated by the derivative of the leverage curve, the steeper it gets, the more it...
Absolutely, the feeling of the progression, how it ramps, would be dictated by the derivative of the leverage curve, the steeper it gets, the more it feels like it ramps up, or that's at least what my intuition says. Thank you for your advice, it is what I've been wanting to do, but I've never been able to find good information on how to calculate all the values I need to know, and I've been looking for a while. Even the knowledge that leverage is the derivative of the axle path will help me do better work. It's going to take a lot of drafting, but that's why I'm getting solid works installed on my computers and am going to start working in that more. I will, ask, how does a linkage factor in to calculating the leverage? I know you can use them to alter the leverage ratio in any layout.
You end up with a bunch of variables. As many as you feel like using really. Changing any dimension causes changes to everything. Knowing what will impact what the most and least is the trick. I always work back from the shock when setting up these equations and end up with something where leverage is a function of three linkage dimensions (since link is a triangle), a second linkage dimension, and shock stroke. Looks something like this:
I've taken to doing the derivative this way because it solves much faster. yw is axle position in y and, while it looks simple there, if I expand out the entire equation there's a lot going on. d, e, and phi are dimensions of a link connected to the shock and c is a dimension of a second link. If you start with the shock it all comes pretty easy. With your more complex layout, starting from the shock you can define position of that first link as a function of shock position and the linkage dimensions. The position of dark blue triangle can then be defined based on the position of that first linkage and the length of the green member that ties the two together. You can then solve for axle position based on the dimensions of the small triangle the axle is connected to as well as the lowermost link.
Started a model for a bike to make for myself. Mostly to try new design ideas and workflows so i can do a better job designing for others and not experiment on clients. This is the v1 of this bike, v2 is in the works with FEA being used during the design process instead of after.
I want to try a bike with a really low leverage. This bike uses 65mm of stroke to achieve 150mm of suspension. My current bike has 58mm of stroke for 150mm so i figured more stroke would feel better and would make shock tuning and damping clicks more effective? some other people ive talked to seem to agree
Have a look at the review of Bird's older bikes, like Aeris AM9 (not Aeris 9), which has 150 mm of travel from a 230x65 shock, or the 27,5" Aeris 145 (or older, aluminium Aeris AM, same bike actually), which has 145 or 160 mm of travel from the same shock. Without the right tune (low damping) it can easily be overdamped.
Absolutely, the feeling of the progression, how it ramps, would be dictated by the derivative of the leverage curve, the steeper it gets, the more it...
Absolutely, the feeling of the progression, how it ramps, would be dictated by the derivative of the leverage curve, the steeper it gets, the more it feels like it ramps up, or that's at least what my intuition says. Thank you for your advice, it is what I've been wanting to do, but I've never been able to find good information on how to calculate all the values I need to know, and I've been looking for a while. Even the knowledge that leverage is the derivative of the axle path will help me do better work. It's going to take a lot of drafting, but that's why I'm getting solid works installed on my computers and am going to start working in that more. I will, ask, how does a linkage factor in to calculating the leverage? I know you can use them to alter the leverage ratio in any layout.
You end up with a bunch of variables. As many as you feel like using really. Changing any dimension causes changes to everything. Knowing what will...
You end up with a bunch of variables. As many as you feel like using really. Changing any dimension causes changes to everything. Knowing what will impact what the most and least is the trick. I always work back from the shock when setting up these equations and end up with something where leverage is a function of three linkage dimensions (since link is a triangle), a second linkage dimension, and shock stroke. Looks something like this:
I've taken to doing the derivative this way because it solves much faster. yw is axle position in y and, while it looks simple there, if I expand out the entire equation there's a lot going on. d, e, and phi are dimensions of a link connected to the shock and c is a dimension of a second link. If you start with the shock it all comes pretty easy. With your more complex layout, starting from the shock you can define position of that first link as a function of shock position and the linkage dimensions. The position of dark blue triangle can then be defined based on the position of that first linkage and the length of the green member that ties the two together. You can then solve for axle position based on the dimensions of the small triangle the axle is connected to as well as the lowermost link.
Doing a clean sheet design, wouldn't it make more sense to start from the rear axle and work out antisquat (and antirise) and then deal with placing the shock on the resulting linkage?
Doing a clean sheet design, wouldn't it make more sense to start from the rear axle and work out antisquat (and antirise) and then deal with...
Doing a clean sheet design, wouldn't it make more sense to start from the rear axle and work out antisquat (and antirise) and then deal with placing the shock on the resulting linkage?
Talking about the math here. Too many unknowns that way since a whole bunch of layouts, technically infinite, can yield more or less the same axle path. It's always an iterative process. To get to the point where the math is reasonable I like to define the start and end point of axle path in CAD and then tweak linkages until they are in a reasonable enough starting spot.
Have a look at the review of Bird's older bikes, like Aeris AM9 (not Aeris 9), which has 150 mm of travel from a 230x65 shock...
Have a look at the review of Bird's older bikes, like Aeris AM9 (not Aeris 9), which has 150 mm of travel from a 230x65 shock, or the 27,5" Aeris 145 (or older, aluminium Aeris AM, same bike actually), which has 145 or 160 mm of travel from the same shock. Without the right tune (low damping) it can easily be overdamped.
Jimmy from Cascade or Dave from Rockshox would be able to speak to this more accurately, but there have been a number of bikes in the past that have tried to use really low leverage ratios (Foes 2:1, Devinci Wilson, early YT Tues, etc) or really high leverage ratios (earlier Santa Cruz V10s, Giant Reign, Specialized Enduro, etc) that made sense on paper and have created consistently bad results in the field. Like Primoz said, low leverage rates are often overdamped and harsh and they create other problems inside the shock, and high leverage rates like to overheat and blow up shocks. In fact, my understanding is that too high of a leverage rate or too low can both have the effect of overheating and blowing up shocks because typical shock architecture isn't designed for the super high flow rates needed to accommodate low leverage rates or the super high damping forces created by high leverage rates. Almost all bikes these days have landed somewhere in the middle on leverage rates.
Yeah super low leverage ratio easily leads to overdamped. Damping force as felt at the wheel is inversely proportional to leverage ratio squared. This is because you divide wheel speed by leverage ratio to get shock speed and then divide damping force at the shock by leverage ratio to get wheel force. Comparing a 150 and 170 bike both running a 65mm stroke, the 150 will on average would have 28% more damping force as you'd feel it at the wheel if both shocks have the same tune. We did a version of the Crestline DH bike that had 180mm of travel using the same 250x75. Using the same comparison, the 180 version of the bike, which is usually 205, generates about 30% more damping force at the wheel on average. The shock needed a retune for damping to feel right. What works well does depend on rider size too, though. Our customer service guy makes an S6 SJ Evo look small and benefits from abnormally low leverage ratios because damping tune no longer needs to be mega stiff and spring rates/pressures can be more average.
Yeah super low leverage ratio easily leads to overdamped. Damping force as felt at the wheel is inversely proportional to leverage ratio squared. This is because...
Yeah super low leverage ratio easily leads to overdamped. Damping force as felt at the wheel is inversely proportional to leverage ratio squared. This is because you divide wheel speed by leverage ratio to get shock speed and then divide damping force at the shock by leverage ratio to get wheel force. Comparing a 150 and 170 bike both running a 65mm stroke, the 150 will on average would have 28% more damping force as you'd feel it at the wheel if both shocks have the same tune. We did a version of the Crestline DH bike that had 180mm of travel using the same 250x75. Using the same comparison, the 180 version of the bike, which is usually 205, generates about 30% more damping force at the wheel on average. The shock needed a retune for damping to feel right. What works well does depend on rider size too, though. Our customer service guy makes an S6 SJ Evo look small and benefits from abnormally low leverage ratios because damping tune no longer needs to be mega stiff and spring rates/pressures can be more average.
So with all that in mind, what sort of leverage would be best for a light weight rider? The one I've been working on has a leverage starting at 2.7 and ending at 2.1 . Not too far off from the bike I'm on now.
I don't mind tuning shocks but it would be cool to just take a shock off the shelf and ride without any extra steps.
Aim for something that works with a medium medium damper tune then. That's the most common on the shelf shock variant which can be quite a pain when trying to adapt it to a certain frame...
Yeah super low leverage ratio easily leads to overdamped. Damping force as felt at the wheel is inversely proportional to leverage ratio squared. This is because...
Yeah super low leverage ratio easily leads to overdamped. Damping force as felt at the wheel is inversely proportional to leverage ratio squared. This is because you divide wheel speed by leverage ratio to get shock speed and then divide damping force at the shock by leverage ratio to get wheel force. Comparing a 150 and 170 bike both running a 65mm stroke, the 150 will on average would have 28% more damping force as you'd feel it at the wheel if both shocks have the same tune. We did a version of the Crestline DH bike that had 180mm of travel using the same 250x75. Using the same comparison, the 180 version of the bike, which is usually 205, generates about 30% more damping force at the wheel on average. The shock needed a retune for damping to feel right. What works well does depend on rider size too, though. Our customer service guy makes an S6 SJ Evo look small and benefits from abnormally low leverage ratios because damping tune no longer needs to be mega stiff and spring rates/pressures can be more average.
So with all that in mind, what sort of leverage would be best for a light weight rider? The one I've been working on has a...
So with all that in mind, what sort of leverage would be best for a light weight rider? The one I've been working on has a leverage starting at 2.7 and ending at 2.1 . Not too far off from the bike I'm on now.
I don't mind tuning shocks but it would be cool to just take a shock off the shelf and ride without any extra steps.
The thing I will say is this, making a frame will cost thousands of dollars (including your labour) and take a lot of time.
Don't sacrifice the suspension design, packaging, frame type etc etc, so it works with an off the shelf damper that somebody can fix for you for $300-450.
Like if your going to the effort of making a sick custom frame, don't make your design constraint 16 tiny thin pieces of metal that can be re-arranged to work better.
Yeah super low leverage ratio easily leads to overdamped. Damping force as felt at the wheel is inversely proportional to leverage ratio squared. This is because...
Yeah super low leverage ratio easily leads to overdamped. Damping force as felt at the wheel is inversely proportional to leverage ratio squared. This is because you divide wheel speed by leverage ratio to get shock speed and then divide damping force at the shock by leverage ratio to get wheel force. Comparing a 150 and 170 bike both running a 65mm stroke, the 150 will on average would have 28% more damping force as you'd feel it at the wheel if both shocks have the same tune. We did a version of the Crestline DH bike that had 180mm of travel using the same 250x75. Using the same comparison, the 180 version of the bike, which is usually 205, generates about 30% more damping force at the wheel on average. The shock needed a retune for damping to feel right. What works well does depend on rider size too, though. Our customer service guy makes an S6 SJ Evo look small and benefits from abnormally low leverage ratios because damping tune no longer needs to be mega stiff and spring rates/pressures can be more average.
So with all that in mind, what sort of leverage would be best for a light weight rider? The one I've been working on has a...
So with all that in mind, what sort of leverage would be best for a light weight rider? The one I've been working on has a leverage starting at 2.7 and ending at 2.1 . Not too far off from the bike I'm on now.
I don't mind tuning shocks but it would be cool to just take a shock off the shelf and ride without any extra steps.
The thing I will say is this, making a frame will cost thousands of dollars (including your labour) and take a lot of time.
Don't sacrifice...
The thing I will say is this, making a frame will cost thousands of dollars (including your labour) and take a lot of time.
Don't sacrifice the suspension design, packaging, frame type etc etc, so it works with an off the shelf damper that somebody can fix for you for $300-450.
Like if your going to the effort of making a sick custom frame, don't make your design constraint 16 tiny thin pieces of metal that can be re-arranged to work better.
Mondraker Foxy uses a 205x65 for 150mm of travel. They use a very light compression and rebound tune.
I know people who can help me either tune a shock off the shelf or buy it pre-tuned.
I'm mostly modeling this frame to test FEA and different ideas that I've had for workflows. There's no guarantee that this or any bike i model for myself is going to be built, I just enjoy the process and the practice. I still need to buy a welder and machines instead of borrowing the equipment at other peoples machine shops. Trying to improve on the first full suspension bike i made.
Started a model for a bike to make for myself. Mostly to try new design ideas and workflows so i can do a better job designing...
Started a model for a bike to make for myself. Mostly to try new design ideas and workflows so i can do a better job designing for others and not experiment on clients. This is the v1 of this bike, v2 is in the works with FEA being used during the design process instead of after.
I want to try a bike with a really low leverage. This bike uses 65mm of stroke to achieve 150mm of suspension. My current bike has 58mm of stroke for 150mm so i figured more stroke would feel better and would make shock tuning and damping clicks more effective? some other people ive talked to seem to agree
I few years ago I made a 150mm rear travel from a 63.5mm stroke shock, so roughly a 2.4 leverage ratio. I love it, but that specific frame had too many QC issues with the hydroformed downtube so I have two new prototypes with the same leverage ratio in my garage that I'm testing.
I feel like low leverage ratios make it much easier to tune the shock, and despite being a flexy single pivot, the shocks I've put on these frames seem to last longer with potentially longer service intervals. The stress on the shock is simply less. For air shocks, its easier to get ramp-up on these linear single pivots, and progressive coils like Cane Creek's have more of an effect than a shorter stroke. On long descents, I feel less fade in the rear, with more consistent rebound performance from the top to bottom, even with non-piggy back shocks.
The caveat is that I've only used Cane Creek (coil and air) that have all their adjustments external, and EXT that was custom valved for the frame. Slap a generic OEM superdeluxe on there and you might have a worse time of things (even with a L/L tune)
Just a thought. I got down voted to oblivion on Pinkbike for daring to say that gearboxes have flaws, and might not be best suited for all applications. My logic was that you are limited in your pedaling efficiency, since you don't have different chain lines per gear that affects your anti squat, and that it would be a compromise, not being able to fine tune the pedaling efficiency depending on the gear you are in. Some people were saying that it is better to get rid of the rear derailleur in favor of the gear box anyways, and that you could use the shock to make up for it, and that it was easier to tune a shock for a single antisquat value than multiple. To me though, I think that that would be loading the shock a lot more, and you would have to run a lot of low speed compression damping to create the same efficient pedaling that a high antisquat value would, which means you would probably want to run a shock with some sort of climb switch that would usually result in less end user adjustability, unless you are spending a ton of money on a shock like the push 11.6 with its separate damping Circuits. Ultimately I think that building pedaling efficiency into the linkage design itself is better than relying on the shock to be firm, and to do that a traditional derailleur and cassette system works the best over a gearbox. What are your thoughts?
Using a gearbox doesn't limit you from making a suspension geometry that gives you the desired antisquat. You can just as easily go well over 100 % AS with a gearbox or fine tune it to a point where you won't need much damping or a climb switch.
A constant chainline with less unknowns is in fact an advantage of a gearbox.
Yeah, I was thinking it could be pretty heavy, due to the size of the two links, and then the extra links, I think it'll be worth mocking up in CAD. I've been working on another design that is giving the same numbers, but with a lot fewer links. It's not quite the same, but I can upload that one too with its kinematics graphs.
Absolutely, and larger bearings usually run a bit smoother and last longer. It's definitely something to consider. I think my current bike, a last gen Norco Sight, is using a 30 mm OD bearing for its main pivot, but compared to something like the Raaw Madonna, even that is tiny. I'm wanting to keep manufacturing and end user service in mind when working on these ideas, and if I can have larger bearings and fewer of them and get mostly the same results, that would be better. I eventually do want to sell the bikes I design, so keeping patents in mind will be important for me. The I Track one is a little irritating though haha. I took a look at the filing and it looks like they patented almost every pattern of suspension with the idler wheel on a link instead of the main frame or pivot that they could think of.
Here is the simpler version, it's not quite the same but it is pretty close and only uses two links.
I guess I just wonder what your goal is.
That leverage ratio looks very different, Anti-rise is pretty different. Also axle path slightly changed and migration of the instant center is opposite. I understand you are messing around and seeing what works.
Just need to figure out what is important to you.
You're right about that. I'm not sure if I fully understand what is important to me right now, so I'm throwing things at the wall to see what sticks. I know what axle path I want (mostly vertical, slightly rearward), about what progression I want ( about 25%, so you can run air and coil shocks easily and I don't want it to feel like you hit a wall of progression), and I want it to be able to pedal pretty efficiently, so that means anti squat values above at or above 100% at sag. The movement of the IC isn't as important to me, so long as the axle path is right. Then, after that, I want it to not be too heavy. Looking at bikes that I have loved before, 2016 Trek Remedy, Ibis Mojo SL, 2021 Niner Rip 9, every Kona process, V2 Santa Cruz Nomad, 2012 Yeti SB66, their kinematics have been all over the place. I personally don't care about complexity, or the number of bearings, six bar links and having 12 bearings doesn't put me off, but more complex links add weight, and I do want to produce my designs to sell eventually. I also have a desire for the layout to be bespoke, something different that stands out, not just another four bar with rocker link, that make up so much of the market right now. Both of the designs that I've put together so far, while different, do hit on the points that I think I want, but the first one is more appealing to me personally since it is more unique, even if that comes with it's own issues, like the size of the bearings in the main pivots, or flex and weight.
Awesome. I was in a similar position as you 2 years ago and was talking with a frame builder about a custom DH bike. Eventually I decided to put my money towards buying and selling multiple frames to test. I learned so much this way to learn what a bike feels like and what it looks like mathematically.
Say, I have “lost” $5,000 over 2 years buying and selling but I’ve been able to own and try 6 different frames. Also getting laps on friends bikes.
It’s much more economical to make sure you test and know what you’d like before producing a $5-$10k frame. Unless you have other ways to make them less expensive.
The best bang for your buck is taking laps on friends bikes and creating or looking up the kinematic. Learn how to feel the difference from the shock and the kinematic.
I've been thinking about asking to ride some of my friends bikes, just for like a lap or so, to see what I like. Who did you work with when you started manufacturing? I don't want to start throwing money at this until I know more about what may work and what I want, but knowing who might be good to work with now can help me plan.
Indeed they did. Idler on the front triangle, on the pivot on the front triangle (essentially front triangle) or on the swingarm (single pivot design) is not patented, everything else is.
I did a similar project for my engineering degree about 3 years ago.
I also started out on Linkage, but also started drawing up things in CAD pretty early too. I did mock-ups of phyisical components i had laying around so i could put them in an assembly in CAD, just to check for clearance issues.
The curves you showed look good in general, just bear in mind, if you're going degressivt to linear to progressive as it is the case on the second layout you posted, the bike could feel harsh on impact when landing after a jump.
Oh, another point, with the second design what kind of shock is used ETE and stroke wise? More importantly, it's getting more and more perpendicular going through the travel, which causes very high loads int he top tube - perpendicular loading will try to bend it the most. I still remember Commencal stating they saved I think 150 grams in the downtube alone going from V2 to V3 Supreme by not mounting the shock (perpendicularly) to the downtube. Top tubes are usually even lighter than the downtube and could thus require an even greater difference in weight to gain the strength. Or a brace like Specialized did with the current (outgoing) Stumpjumper - the previous variant apparently kicked back from full travel fairly undamped in the carbon variant as the top tube acted like a bow getting loaded up going through the travel.
Remember a couple of years ago when people on mtbr (I think) started lacing their nylon spokes with a system that closely resembled berd wheels and their legal representative posted that they are not allowed to do so and threatened with legal action if schemes are not taken off... I still don't believe they would actually take the matter to the court but they were super agressive with their response.
I worked with Frank The Welder when I was in high school so he was the first one I reached out to. He’s most recently come back into the spot light working with Neko and Frameworks.
https://www.frankthewelder.com/
But I just completed a steel DH frame project with Adam Prosise who did an incredible job. He’s got an unbelievable attention to detail. Was able to get 3d printed steel parts for my frame also. Instagram- @prosisemetalworks
One of the constraints I gave my self was using only readily available shock sizes, so both versions use a 205x60 standard eyelet shock, to give 160ish travel. I can totally see your point about loading the top tube up with the force applied to the shock, causing it to bow and react like a spring itself. That point on the top tube would likely have to be reinforced to keep it from acting like that.
That's always a good reaction for a company to have, people usually love companies like that...
@Eae903 my two cents on designing suspension when you are currently studying engineering... I know it takes more time, but you have the math background. Try and work out kinematics outside of linkage. You'll learn a ton. Travel is the integral of leverage curve, leverage is the derivative of axle position (usually in the y axis, but leverage curves can be made for any axis). All you really have to do is find axle path and the rest comes easy. It's like how they don't want you to use calculators or computers in math class until you understand the math that's actually being done. Also don't put too much store in things you read on the various MTB websites. Especially on PB I see journalists make a lot of assumptions about how suspension should work that aren't necessarily accurate. For example "while the high overall progression (36%) means things will ramp up quickly in the last 25mm of travel." Sometimes that statement is true, but it is not always true. In fact there are a good number of bikes out there where the ramp up exists primarily in the first part of travel, such as the Ibis Ripmo and Evil Offering.
Absolutely, the feeling of the progression, how it ramps, would be dictated by the derivative of the leverage curve, the steeper it gets, the more it feels like it ramps up, or that's at least what my intuition says. Thank you for your advice, it is what I've been wanting to do, but I've never been able to find good information on how to calculate all the values I need to know, and I've been looking for a while. Even the knowledge that leverage is the derivative of the axle path will help me do better work. It's going to take a lot of drafting, but that's why I'm getting solid works installed on my computers and am going to start working in that more. I will, ask, how does a linkage factor in to calculating the leverage? I know you can use them to alter the leverage ratio in any layout.
You end up with a bunch of variables. As many as you feel like using really. Changing any dimension causes changes to everything. Knowing what will impact what the most and least is the trick. I always work back from the shock when setting up these equations and end up with something where leverage is a function of three linkage dimensions (since link is a triangle), a second linkage dimension, and shock stroke. Looks something like this:
I've taken to doing the derivative this way because it solves much faster. yw is axle position in y and, while it looks simple there, if I expand out the entire equation there's a lot going on. d, e, and phi are dimensions of a link connected to the shock and c is a dimension of a second link. If you start with the shock it all comes pretty easy. With your more complex layout, starting from the shock you can define position of that first link as a function of shock position and the linkage dimensions. The position of dark blue triangle can then be defined based on the position of that first linkage and the length of the green member that ties the two together. You can then solve for axle position based on the dimensions of the small triangle the axle is connected to as well as the lowermost link.
I want to try a bike with a really low leverage. This bike uses 65mm of stroke to achieve 150mm of suspension. My current bike has 58mm of stroke for 150mm so i figured more stroke would feel better and would make shock tuning and damping clicks more effective? some other people ive talked to seem to agree
Have a look at the review of Bird's older bikes, like Aeris AM9 (not Aeris 9), which has 150 mm of travel from a 230x65 shock, or the 27,5" Aeris 145 (or older, aluminium Aeris AM, same bike actually), which has 145 or 160 mm of travel from the same shock. Without the right tune (low damping) it can easily be overdamped.
Doing a clean sheet design, wouldn't it make more sense to start from the rear axle and work out antisquat (and antirise) and then deal with placing the shock on the resulting linkage?
Talking about the math here. Too many unknowns that way since a whole bunch of layouts, technically infinite, can yield more or less the same axle path. It's always an iterative process. To get to the point where the math is reasonable I like to define the start and end point of axle path in CAD and then tweak linkages until they are in a reasonable enough starting spot.
Jimmy from Cascade or Dave from Rockshox would be able to speak to this more accurately, but there have been a number of bikes in the past that have tried to use really low leverage ratios (Foes 2:1, Devinci Wilson, early YT Tues, etc) or really high leverage ratios (earlier Santa Cruz V10s, Giant Reign, Specialized Enduro, etc) that made sense on paper and have created consistently bad results in the field. Like Primoz said, low leverage rates are often overdamped and harsh and they create other problems inside the shock, and high leverage rates like to overheat and blow up shocks. In fact, my understanding is that too high of a leverage rate or too low can both have the effect of overheating and blowing up shocks because typical shock architecture isn't designed for the super high flow rates needed to accommodate low leverage rates or the super high damping forces created by high leverage rates. Almost all bikes these days have landed somewhere in the middle on leverage rates.
Yeah super low leverage ratio easily leads to overdamped. Damping force as felt at the wheel is inversely proportional to leverage ratio squared. This is because you divide wheel speed by leverage ratio to get shock speed and then divide damping force at the shock by leverage ratio to get wheel force. Comparing a 150 and 170 bike both running a 65mm stroke, the 150 will on average would have 28% more damping force as you'd feel it at the wheel if both shocks have the same tune. We did a version of the Crestline DH bike that had 180mm of travel using the same 250x75. Using the same comparison, the 180 version of the bike, which is usually 205, generates about 30% more damping force at the wheel on average. The shock needed a retune for damping to feel right. What works well does depend on rider size too, though. Our customer service guy makes an S6 SJ Evo look small and benefits from abnormally low leverage ratios because damping tune no longer needs to be mega stiff and spring rates/pressures can be more average.
So with all that in mind, what sort of leverage would be best for a light weight rider? The one I've been working on has a leverage starting at 2.7 and ending at 2.1 . Not too far off from the bike I'm on now.
I don't mind tuning shocks but it would be cool to just take a shock off the shelf and ride without any extra steps.
Aim for something that works with a medium medium damper tune then. That's the most common on the shelf shock variant which can be quite a pain when trying to adapt it to a certain frame...
The thing I will say is this, making a frame will cost thousands of dollars (including your labour) and take a lot of time.
Don't sacrifice the suspension design, packaging, frame type etc etc, so it works with an off the shelf damper that somebody can fix for you for $300-450.
Like if your going to the effort of making a sick custom frame, don't make your design constraint 16 tiny thin pieces of metal that can be re-arranged to work better.
Mondraker Foxy uses a 205x65 for 150mm of travel. They use a very light compression and rebound tune.
I know people who can help me either tune a shock off the shelf or buy it pre-tuned.
I'm mostly modeling this frame to test FEA and different ideas that I've had for workflows. There's no guarantee that this or any bike i model for myself is going to be built, I just enjoy the process and the practice. I still need to buy a welder and machines instead of borrowing the equipment at other peoples machine shops. Trying to improve on the first full suspension bike i made.
https://www.vitalmtb.com/community/hamncheez2003,27159/setup,44451
I few years ago I made a 150mm rear travel from a 63.5mm stroke shock, so roughly a 2.4 leverage ratio. I love it, but that specific frame had too many QC issues with the hydroformed downtube so I have two new prototypes with the same leverage ratio in my garage that I'm testing.
I feel like low leverage ratios make it much easier to tune the shock, and despite being a flexy single pivot, the shocks I've put on these frames seem to last longer with potentially longer service intervals. The stress on the shock is simply less. For air shocks, its easier to get ramp-up on these linear single pivots, and progressive coils like Cane Creek's have more of an effect than a shorter stroke. On long descents, I feel less fade in the rear, with more consistent rebound performance from the top to bottom, even with non-piggy back shocks.
The caveat is that I've only used Cane Creek (coil and air) that have all their adjustments external, and EXT that was custom valved for the frame. Slap a generic OEM superdeluxe on there and you might have a worse time of things (even with a L/L tune)
Just a thought. I got down voted to oblivion on Pinkbike for daring to say that gearboxes have flaws, and might not be best suited for all applications. My logic was that you are limited in your pedaling efficiency, since you don't have different chain lines per gear that affects your anti squat, and that it would be a compromise, not being able to fine tune the pedaling efficiency depending on the gear you are in. Some people were saying that it is better to get rid of the rear derailleur in favor of the gear box anyways, and that you could use the shock to make up for it, and that it was easier to tune a shock for a single antisquat value than multiple. To me though, I think that that would be loading the shock a lot more, and you would have to run a lot of low speed compression damping to create the same efficient pedaling that a high antisquat value would, which means you would probably want to run a shock with some sort of climb switch that would usually result in less end user adjustability, unless you are spending a ton of money on a shock like the push 11.6 with its separate damping Circuits. Ultimately I think that building pedaling efficiency into the linkage design itself is better than relying on the shock to be firm, and to do that a traditional derailleur and cassette system works the best over a gearbox. What are your thoughts?
Using a gearbox doesn't limit you from making a suspension geometry that gives you the desired antisquat. You can just as easily go well over 100 % AS with a gearbox or fine tune it to a point where you won't need much damping or a climb switch.
A constant chainline with less unknowns is in fact an advantage of a gearbox.
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