Peak bending moment occurs at the axle end of the seat stay. This snapping is unrelated to the flex stay if it's happening at the linkage...
Peak bending moment occurs at the axle end of the seat stay. This snapping is unrelated to the flex stay if it's happening at the linkage end. Looks like it's a compression failure in the tube that wouldn't be fixed by adding.the bearing.
Also given the brake mount location the actual angle change on the flex stay is negligible and the 6 bar description is more academic then actually measurable. That said I've not modelled the kinematic myself.
BK says why not have a light frame, not sure the warranty department will agree with him. Seems an odd goal to go for with a modern DH bike, sure make it not a tank, but weight weenies aren't buying DH bikes.
Peak bending moment occurs at the axle end of the seat stay. This snapping is unrelated to the flex stay if it's happening at the linkage...
Peak bending moment occurs at the axle end of the seat stay. This snapping is unrelated to the flex stay if it's happening at the linkage end. Looks like it's a compression failure in the tube that wouldn't be fixed by adding.the bearing.
Also given the brake mount location the actual angle change on the flex stay is negligible and the 6 bar description is more academic then actually measurable. That said I've not modelled the kinematic myself.
Peak bending moment occurs at the axle end of the seat stay. This snapping is unrelated to the flex stay if it's happening at the linkage...
Peak bending moment occurs at the axle end of the seat stay. This snapping is unrelated to the flex stay if it's happening at the linkage end. Looks like it's a compression failure in the tube that wouldn't be fixed by adding.the bearing.
Also given the brake mount location the actual angle change on the flex stay is negligible and the 6 bar description is more academic then actually measurable. That said I've not modelled the kinematic myself.
Not sure what's meant by that last bit, but no matter. When I say robust mount, I mean in light of taking cross sectional load off the...
Not sure what's meant by that last bit, but no matter.
When I say robust mount, I mean in light of taking cross sectional load off the mount screws as well as creating a stiffer interface between the caliper and the frame, which post mount does. Brake force is applied directly to the mount, not through the screws. Some IS mounts are flexy buggers, which results in noise and worse case, vibration. Post Mount pretty much does away with that. Like all things, end game is about tradeoffs. IS is easier to manufacture, PM creates a better interface.
As someone with a front seat on brake mount designs/development for a number of years, there are pros and cons to each mounting method depending on...
As someone with a front seat on brake mount designs/development for a number of years, there are pros and cons to each mounting method depending on the material and frame design, and the intended customer. Often the intended customer preference outweighs the best possible engineered solution. Shear force loading the caliper bolts is a non-issue in most cycling applications. For a steel frame, the complexity and cost of using either a post mount or direct mount design might go against the simplicity and cost reduction goals of that project. Those customers might prefer something simple, inexpensive, and easy to use. Post or direct mount forgings are also subject to failure at the weld from design or fabrication errors. TLDR; you can't apply a blanket solution for all applications.
Back to rumours; I look forward to evolving brake designs that Sram's direct mount design will create.
BK says why not have a light frame, not sure the warranty department will agree with him. Seems an odd goal to go for with a...
BK says why not have a light frame, not sure the warranty department will agree with him. Seems an odd goal to go for with a modern DH bike, sure make it not a tank, but weight weenies aren't buying DH bikes.
Your point is valid but I’d take it a step further and say hell no to a light bike due to safety. In my view, frame failures (especially DH bikes meant to hit huge features) are just as bad as helmet failures, full stop.
The Main DH bikes Weve seen in the media breaking have been marketed as light DH bikes, such as the gambler (team changed to the alloy one for a bit) and pivot - both carbon, i dont think its a carbon itself issue but more of a design and choice of layup thickness etc
personally my DH weighs upwards of 19kg with 500g weight under the BB. the things a rocket ship. as BK said, DH tracks are much faster these days and many of the Trek riders said not to make a carbon version of the HP session(this was in a media interview) as the weight and flex of alloy seems to make them go good.
The only time i've whinged about the weight of my bikes is putting them on my rack which is a non issue haha
Not really a tech rumour but a tech wish: since we’ve somewhat stabilized on geo development and are looking at new ways to innovate, can companies put more effort into silencing bikes? It’s kind of embarrassing that a $10k bike sounds like a shopping cart.
Not really a tech rumour but a tech wish: since we’ve somewhat stabilized on geo development and are looking at new ways to innovate, can companies...
Not really a tech rumour but a tech wish: since we’ve somewhat stabilized on geo development and are looking at new ways to innovate, can companies put more effort into silencing bikes? It’s kind of embarrassing that a $10k bike sounds like a shopping cart.
Baseball card holder tab on my seat stay so I can have a good sounding motorbicycle thing. Thats a industry standard we need.
Some of you never rode when we had no clutches so the loose, flopping chain smashed against every part of your aluminum bike and the fork knocked in the 1 1/8th head tubes and then echoed through your monocoque frame and it shows.
I can barely hear my current bike compared to the 3rd grade marching bands on wheels we used to ride pre-2012. I didn't even know you could hear what your tires were doing for the first 10 years I rode.
Some of you never rode when we had no clutches so the loose, flopping chain smashed against every part of your aluminum bike and the fork...
Some of you never rode when we had no clutches so the loose, flopping chain smashed against every part of your aluminum bike and the fork knocked in the 1 1/8th head tubes and then echoed through your monocoque frame and it shows.
I can barely hear my current bike compared to the 3rd grade marching bands on wheels we used to ride pre-2012. I didn't even know you could hear what your tires were doing for the first 10 years I rode.
I did. But I still expect better. We are talking five figure bikes that can be solved with some clamps and mastic tape or a little oval thing. Why is that left to the customers to figure out where it goes?
Some of you never rode when we had no clutches so the loose, flopping chain smashed against every part of your aluminum bike and the fork...
Some of you never rode when we had no clutches so the loose, flopping chain smashed against every part of your aluminum bike and the fork knocked in the 1 1/8th head tubes and then echoed through your monocoque frame and it shows.
I can barely hear my current bike compared to the 3rd grade marching bands on wheels we used to ride pre-2012. I didn't even know you could hear what your tires were doing for the first 10 years I rode.
My $8000 bike I bought a year ago with a clutch derailleur still sounds like garbage so I think they still need to work on it.
Agree. I think running a chainguide with a lower roller helps a ton, it eliminates a lot of metallic clinking noise of the chain tapping on the chainring as it bounces around.
Is this the linkage end?
BK says why not have a light frame, not sure the warranty department will agree with him. Seems an odd goal to go for with a modern DH bike, sure make it not a tank, but weight weenies aren't buying DH bikes.
Yes this is the linkage end. That's where it snapped in Tasmania as I recall.
He snapped the chain stays and seat stays at hardline.
The picture above was at PDS rock creek
Last year's prototype Demo with a TTX22m.2 installed?
Tell us more.
https://cyclingmagazine.ca/mtb/specialized-finally-reveals-finn-iles-pr…
I didn't look at the image properly the first time - that's pretty catastrophic! Although fixable with a modified layup!
Who's bike was it?
just thought it was a good angle, better than i previously recall seeing.
I thought the wear marks in this pic were interesting
Your point is valid but I’d take it a step further and say hell no to a light bike due to safety. In my view, frame failures (especially DH bikes meant to hit huge features) are just as bad as helmet failures, full stop.
The Main DH bikes Weve seen in the media breaking have been marketed as light DH bikes, such as the gambler (team changed to the alloy one for a bit) and pivot - both carbon, i dont think its a carbon itself issue but more of a design and choice of layup thickness etc
personally my DH weighs upwards of 19kg with 500g weight under the BB. the things a rocket ship. as BK said, DH tracks are much faster these days and many of the Trek riders said not to make a carbon version of the HP session(this was in a media interview) as the weight and flex of alloy seems to make them go good.
The only time i've whinged about the weight of my bikes is putting them on my rack which is a non issue haha
Not really a tech rumour but a tech wish: since we’ve somewhat stabilized on geo development and are looking at new ways to innovate, can companies put more effort into silencing bikes? It’s kind of embarrassing that a $10k bike sounds like a shopping cart.
Baseball card holder tab on my seat stay so I can have a good sounding motorbicycle thing. Thats a industry standard we need.
Some of you never rode when we had no clutches so the loose, flopping chain smashed against every part of your aluminum bike and the fork knocked in the 1 1/8th head tubes and then echoed through your monocoque frame and it shows.
I can barely hear my current bike compared to the 3rd grade marching bands on wheels we used to ride pre-2012. I didn't even know you could hear what your tires were doing for the first 10 years I rode.
I did. But I still expect better. We are talking five figure bikes that can be solved with some clamps and mastic tape or a little oval thing. Why is that left to the customers to figure out where it goes?
My $8000 bike I bought a year ago with a clutch derailleur still sounds like garbage so I think they still need to work on it.
Agree. I think running a chainguide with a lower roller helps a ton, it eliminates a lot of metallic clinking noise of the chain tapping on the chainring as it bounces around.
STFU guides. They actually work. They also help with the mythical pedal kickback.
External cables with proper guides/clamps.
Lastly a silent rear hub.
But none of it really matters when you ride solo with earbuds in 90% of the time.
Guess I found the new Levo Alloy in the wild. With a S-Works motor.
I’m more confused on why they’re running xts with centerlines
i guess parts bin build, maybe to not attract attention?
I'm more curious about the new bike rack that mounts to the front wheel of a car.
Is it available for older 4 bolt hubs?
Normal rack 4 bolts, S-Works rack 5 bolts.
That's either a new model or a test mule! Nice spot!
This one goes to class 11.
New TR11 build kits, colors, geo and kinematic updates on Transition's website
https://www.transitionbikes.com/Bikes_TR11.cfm
What do you mean, refined? It’s the exact same thing as it was before. All they did was just choose two different colors.
really cool data logging/bike setup post using a jekyll - https://www.vitalmtb.com/forums/hub/case-study-jekyll-dh-data-logging-s…