You’re complaining about a light initial pull with linear force through the bite point as mushy, but ok with the mavens lightening past the breakaway point? If...
You’re complaining about a light initial pull with linear force through the bite point as mushy, but ok with the mavens lightening past the breakaway point?
If like you said it’s a question of dragging the brake, why is the light pull on the hopes such an issue?
And right above that post someone else is saying that the misunderstood thing about the mavens is that the force is linear through the bite point.
I think he's saying that the hopes don't have enough positive feedback at the lever when they make contact with the rotor. Having positive feedback when...
I think he's saying that the hopes don't have enough positive feedback at the lever when they make contact with the rotor. Having positive feedback when the brakes bite at the lever isn't mutually exclusive to having a light dead stroke and good modulation. I haven't used hopes before so I don't know how they feel, but if it is hard to feel when they bite I totally understand not liking them for that reason.
Correct, the Hopes lack feedback when the pads contact the rotor. There’s also a lot of physical lever movement required to go from say 10% to 60% brake force. I’m pretty sure this is just a limitation of physics when the master cylinder has a big mechanical advantage over the pistons and you don’t have a cam or link to change the movement ratio from the lever.
The mavens require far less lever travel to ramp up in brake force. This gives them an initial impression of being grabby and lacking modulation. After a few laps, you realize that they’re actually pretty communicative but you have to pay attention to the feel of lever pressure more than lever position.
A fun quirk of the Hope levers that someone pointed out to me and now I can’t not notice. The lever throw is slightly off axis from the handlebar.
I think he's saying that the hopes don't have enough positive feedback at the lever when they make contact with the rotor. Having positive feedback when...
I think he's saying that the hopes don't have enough positive feedback at the lever when they make contact with the rotor. Having positive feedback when the brakes bite at the lever isn't mutually exclusive to having a light dead stroke and good modulation. I haven't used hopes before so I don't know how they feel, but if it is hard to feel when they bite I totally understand not liking them for that reason.
This was my observation when I ran them, same thing with the Maximas. You don't get that sortof pressure on the lever when you pull it and the pads engage, it's there but it's a lot more subtle than most brakes.
I think it comes down to preference more than anything, the Intends have similar power to the above but provide that feedback, which is why I preferred them.
Like you said, it is preference at the end of the day and we are lucky to have so many good options nowadays. I prefer that softer bite point of Trickstuff Maxima brakes which is why I sold the Intend Trinity.
You’re complaining about a light initial pull with linear force through the bite point as mushy, but ok with the mavens lightening past the breakaway point? If...
You’re complaining about a light initial pull with linear force through the bite point as mushy, but ok with the mavens lightening past the breakaway point?
If like you said it’s a question of dragging the brake, why is the light pull on the hopes such an issue?
And right above that post someone else is saying that the misunderstood thing about the mavens is that the force is linear through the bite point.
I think he's saying that the hopes don't have enough positive feedback at the lever when they make contact with the rotor. Having positive feedback when...
I think he's saying that the hopes don't have enough positive feedback at the lever when they make contact with the rotor. Having positive feedback when the brakes bite at the lever isn't mutually exclusive to having a light dead stroke and good modulation. I haven't used hopes before so I don't know how they feel, but if it is hard to feel when they bite I totally understand not liking them for that reason.
Correct, the Hopes lack feedback when the pads contact the rotor. There’s also a lot of physical lever movement required to go from say 10% to...
Correct, the Hopes lack feedback when the pads contact the rotor. There’s also a lot of physical lever movement required to go from say 10% to 60% brake force. I’m pretty sure this is just a limitation of physics when the master cylinder has a big mechanical advantage over the pistons and you don’t have a cam or link to change the movement ratio from the lever.
The mavens require far less lever travel to ramp up in brake force. This gives them an initial impression of being grabby and lacking modulation. After a few laps, you realize that they’re actually pretty communicative but you have to pay attention to the feel of lever pressure more than lever position.
A fun quirk of the Hope levers that someone pointed out to me and now I can’t not notice. The lever throw is slightly off axis from the handlebar.
The quirk, is it present on all of them? Or is it a case of a bent master cylinder?
I think he's saying that the hopes don't have enough positive feedback at the lever when they make contact with the rotor. Having positive feedback when...
I think he's saying that the hopes don't have enough positive feedback at the lever when they make contact with the rotor. Having positive feedback when the brakes bite at the lever isn't mutually exclusive to having a light dead stroke and good modulation. I haven't used hopes before so I don't know how they feel, but if it is hard to feel when they bite I totally understand not liking them for that reason.
Correct, the Hopes lack feedback when the pads contact the rotor. There’s also a lot of physical lever movement required to go from say 10% to...
Correct, the Hopes lack feedback when the pads contact the rotor. There’s also a lot of physical lever movement required to go from say 10% to 60% brake force. I’m pretty sure this is just a limitation of physics when the master cylinder has a big mechanical advantage over the pistons and you don’t have a cam or link to change the movement ratio from the lever.
The mavens require far less lever travel to ramp up in brake force. This gives them an initial impression of being grabby and lacking modulation. After a few laps, you realize that they’re actually pretty communicative but you have to pay attention to the feel of lever pressure more than lever position.
A fun quirk of the Hope levers that someone pointed out to me and now I can’t not notice. The lever throw is slightly off axis from the handlebar.
The heavy pull force on mavens is only the static friction breakaway force as you move past the start of the cam. It’s a bit like...
The heavy pull force on mavens is only the static friction breakaway force as you move past the start of the cam. It’s a bit like getting a Shimano servowave lever moving.
Once you have the brake lever moved a couple of mm it lightens up dramatically. If you’re dragging the brakes you’re not fighting it. That’s the elephant in the room that Dale Stone’s test did not show. It’s borderline disingenuous that he failed to explain it IMO.
Also the Enduro-MTB dyno test sold Mavens short because they tested them with organic pads against brakes with metallic pads or aftermarket pads.
I felt like the mavens lever pull was heavier through the whole dead stroke, not just at the break away. Like the lever pushed back into...
I felt like the mavens lever pull was heavier through the whole dead stroke, not just at the break away. Like the lever pushed back into my finder harder the whole time I was on them until the bite point. If I was dragging those brakes I would have felt more fatigue compared to a different brake. They could have been set up poorly, I'm not sure I didn't set them up. Just different experiences with them I guess.
Yeah, I am inclined to agree with you regarding the heavier pull, and I don't understand why people don't seem to recognize that most levers have a return spring and these return springs vary wildly in the force they generate. I personally like a very light feeling free stroke, both for feel, and for fatigue reasons, and have thought about trying to swap springs in brakes with heavier springs fitted stock.
Yeah, I am inclined to agree with you regarding the heavier pull, and I don't understand why people don't seem to recognize that most levers have...
Yeah, I am inclined to agree with you regarding the heavier pull, and I don't understand why people don't seem to recognize that most levers have a return spring and these return springs vary wildly in the force they generate. I personally like a very light feeling free stroke, both for feel, and for fatigue reasons, and have thought about trying to swap springs in brakes with heavier springs fitted stock.
Part of it is the cam profile. It’s more aggressive to advance the pistons to contact the rotor sooner. How they get the pad retract they have with such massive pistons. But that does mean there’s less mechanical advantage over the spring.
Part of it is the cam profile. It’s more aggressive to advance the pistons to contact the rotor sooner. How they get the pad retract they...
Part of it is the cam profile. It’s more aggressive to advance the pistons to contact the rotor sooner. How they get the pad retract they have with such massive pistons. But that does mean there’s less mechanical advantage over the spring.
another thing is also how easy those piston move, on my mt7 and on the hopes i mounted today you can push the pistons back with the tip of your finger, generally on codes and g2, they're hard as to push back, a bit less after the famous "massage", Mavens felt a bit softer to push back, again better after the massage.
another thing is also how easy those piston move, on my mt7 and on the hopes i mounted today you can push the pistons back with...
another thing is also how easy those piston move, on my mt7 and on the hopes i mounted today you can push the pistons back with the tip of your finger, generally on codes and g2, they're hard as to push back, a bit less after the famous "massage", Mavens felt a bit softer to push back, again better after the massage.
One thing to keep in mind, though, is that the pistons don’t really physically slide against the seals when you squeeze the lever. The seals flex outward with the piston. The only sliding is to accommodate pad wear. Along with that, the seal grooves are cut to give the seals room to flex outward but not so much inward. This all makes it harder to gauge the resistance you’d feel due to seals. That said, I do think the seals likely take a little more force to deform than on a lot of brakes. My overall impression of the Mavens is that they are built to be powerful and reliable. That comes at the expense of weight and, at times, a stiffer feel. Whether or not the reliability is real is debatable, although I’ve found once set up they are pretty trouble-free. But from that standpoint I wish they were DOT.
On a side note the fact that pistons don’t really slide in the seals much to speak of is why the marketing angles of different piston materials giving the brakes a smoother feel are kind of nonsense. When there’s no relative motion, the seals and pistons have no idea what the coefficient of friction of that interface is.
another thing is also how easy those piston move, on my mt7 and on the hopes i mounted today you can push the pistons back with...
another thing is also how easy those piston move, on my mt7 and on the hopes i mounted today you can push the pistons back with the tip of your finger, generally on codes and g2, they're hard as to push back, a bit less after the famous "massage", Mavens felt a bit softer to push back, again better after the massage.
One thing to keep in mind, though, is that the pistons don’t really physically slide against the seals when you squeeze the lever. The seals flex...
One thing to keep in mind, though, is that the pistons don’t really physically slide against the seals when you squeeze the lever. The seals flex outward with the piston. The only sliding is to accommodate pad wear. Along with that, the seal grooves are cut to give the seals room to flex outward but not so much inward. This all makes it harder to gauge the resistance you’d feel due to seals. That said, I do think the seals likely take a little more force to deform than on a lot of brakes. My overall impression of the Mavens is that they are built to be powerful and reliable. That comes at the expense of weight and, at times, a stiffer feel. Whether or not the reliability is real is debatable, although I’ve found once set up they are pretty trouble-free. But from that standpoint I wish they were DOT.
On a side note the fact that pistons don’t really slide in the seals much to speak of is why the marketing angles of different piston materials giving the brakes a smoother feel are kind of nonsense. When there’s no relative motion, the seals and pistons have no idea what the coefficient of friction of that interface is.
I think the different material of pistons could be more to handle heat differently
Say a ceramic piston vs a stainless vs ergal
Wouldn’t know which one is better
For example Billet factory in Italy is making some 7075 ergal pistons for the hope v4 that are a tad longer to accommodate better the use of thinner rotors
I’m not sure how that would change the brakes given the stock pistons are steel with a sort f resin insert.
Also, why would you wish they were ( the Maven ) Dot vs a better Mineral then maxima? Like Bionol, gold hydraulic or Pluto line
I think the different material of pistons could be more to handle heat differently Say a ceramic piston vs a stainless vs ergalWouldn’t know which one is...
I think the different material of pistons could be more to handle heat differently
Say a ceramic piston vs a stainless vs ergal
Wouldn’t know which one is better
For example Billet factory in Italy is making some 7075 ergal pistons for the hope v4 that are a tad longer to accommodate better the use of thinner rotors
I’m not sure how that would change the brakes given the stock pistons are steel with a sort f resin insert.
Also, why would you wish they were ( the Maven ) Dot vs a better Mineral then maxima? Like Bionol, gold hydraulic or Pluto line
DOT can be left unattended for longer. I think it would be cool to have brakes that are as reliable and low maintenance as car brakes and that would require DOT.
In regards to heat, ceramic and phenolic pistons are superior. Stainless with an insert is decent too if the insert material insulates well. Straight metal pistons have a noticeable negative impact on brake fluid temp even on trails that aren’t too crazy. Stainless pistons result in the brake fluid getting 10% hotter pretty much instantly.
I think the different material of pistons could be more to handle heat differently Say a ceramic piston vs a stainless vs ergalWouldn’t know which one is...
I think the different material of pistons could be more to handle heat differently
Say a ceramic piston vs a stainless vs ergal
Wouldn’t know which one is better
For example Billet factory in Italy is making some 7075 ergal pistons for the hope v4 that are a tad longer to accommodate better the use of thinner rotors
I’m not sure how that would change the brakes given the stock pistons are steel with a sort f resin insert.
Also, why would you wish they were ( the Maven ) Dot vs a better Mineral then maxima? Like Bionol, gold hydraulic or Pluto line
DOT can be left unattended for longer. I think it would be cool to have brakes that are as reliable and low maintenance as car brakes...
DOT can be left unattended for longer. I think it would be cool to have brakes that are as reliable and low maintenance as car brakes and that would require DOT.
In regards to heat, ceramic and phenolic pistons are superior. Stainless with an insert is decent too if the insert material insulates well. Straight metal pistons have a noticeable negative impact on brake fluid temp even on trails that aren’t too crazy. Stainless pistons result in the brake fluid getting 10% hotter pretty much instantly.
any thoughts a piston like this one compared like before to the other options? it's 7075 with a magnet.
also curious if the bare stainless are getting the fluid hotter than others why Trickstuff and Intend and Radic use them vs hope style with the phenolic insert to fill it or ceramic insert like Lewis.
Since there is only a small edge of the stainless piston that is touching the brake pad that mean heat transfer is mostly from the air pocket between the brake pad and the bottom of the stainless piston ? A solid stainless piston would fare much worse in terms of heat capacity and transfer ?
Since there is only a small edge of the stainless piston that is touching the brake pad that mean heat transfer is mostly from the air...
Since there is only a small edge of the stainless piston that is touching the brake pad that mean heat transfer is mostly from the air pocket between the brake pad and the bottom of the stainless piston ? A solid stainless piston would fare much worse in terms of heat capacity and transfer ?
Even with a thin piston wall in contact with the pad there is still significantly more heat transfer than other materials. Hard to get convection to out weigh conduction when it comes to heat transfer. When we were developing brake calipers, we really wanted to do stainless pistons because it's much easier to make stainless pistons, but the numbers just don't agree. This was testing comparing the temperature of the caliper body with stainless pistons similar to what you've described and phenolic pistons. The track was up on Chuckanut so nothing crazy.
any thoughts a piston like this one compared like before to the other options? it's 7075 with a magnet. also curious if the bare stainless are getting...
any thoughts a piston like this one compared like before to the other options? it's 7075 with a magnet.
also curious if the bare stainless are getting the fluid hotter than others why Trickstuff and Intend and Radic use them vs hope style with the phenolic insert to fill it or ceramic insert like Lewis.
I would avoid aluminum pistons like the plague. The thermal conductivity of aluminum is very high. I want to say like 4x that of stainless at least. Not what you want in a brake caliper.
Stainless with a phenolic insert works well too. Stainless pistons are just easier to make or source. Phenolic pistons are a very specific resin that is molded at rather high pressures and then ground to the right dimension. Requires specific machinery whereas a stainless piston can be made on any mill or lathe.
What about a double walled piston where an internal cylinder interfaces with the pad, the outer with the seal and the only link between them is the back face of the piston. So you do not heat the oil via the cylinder sleeve, only via transfer along the inner wall into the inner face.
How about filling stainless steel pistons with a high temp epoxy and inset a neodymium magnet before it cures? That way you can have ease of manufacturing, good thermals and magnetic pistons
DOT can be left unattended for longer. I think it would be cool to have brakes that are as reliable and low maintenance as car brakes...
DOT can be left unattended for longer. I think it would be cool to have brakes that are as reliable and low maintenance as car brakes and that would require DOT.
In regards to heat, ceramic and phenolic pistons are superior. Stainless with an insert is decent too if the insert material insulates well. Straight metal pistons have a noticeable negative impact on brake fluid temp even on trails that aren’t too crazy. Stainless pistons result in the brake fluid getting 10% hotter pretty much instantly.
I see what you mean if we are actually comparing brake maintenance requirements of a DOT car vs. a mineral oil bike but that is an apples and oranges comparison because...
The car is an open system, and the air space at the top of the reservoir can self adjust to accommodate for fluid volume growth due to moisture absorption.
In our bike brakes, which have a membrane sealed reservoir, with very little room to accommodate for fluid volume growth, my experience is that a DOT bike left unattended in garage or shed in a humid environment for a year or 2 will absorb enough moisture to exhibit signs of overfilling, and will either leak out the reservoir cap (causing corrosion of the controls) or not leak but auto-apply the brake. Either way, it is a real PITA if you have a bunch of bikes that see little use, and you want to grab one on short notice as a loaner, or because your primary ride is out of commission, as you basically need to do a mini bleed before each time you use the bike. In my experience, the equivalent mineral oil brake would still be working fine after sitting in that same environment for the same period of time.
You really know your stuff though, and it sounds like you are attuned to some issues associated with long term use of mineral oil that I am not, possibly related to more intense use cases, so what's the deal? What specific problems occur to mineral oil brakes that a switch to DOT would remedy?
I see what you mean if we are actually comparing brake maintenance requirements of a DOT car vs. a mineral oil bike but that is an...
I see what you mean if we are actually comparing brake maintenance requirements of a DOT car vs. a mineral oil bike but that is an apples and oranges comparison because...
The car is an open system, and the air space at the top of the reservoir can self adjust to accommodate for fluid volume growth due to moisture absorption.
In our bike brakes, which have a membrane sealed reservoir, with very little room to accommodate for fluid volume growth, my experience is that a DOT bike left unattended in garage or shed in a humid environment for a year or 2 will absorb enough moisture to exhibit signs of overfilling, and will either leak out the reservoir cap (causing corrosion of the controls) or not leak but auto-apply the brake. Either way, it is a real PITA if you have a bunch of bikes that see little use, and you want to grab one on short notice as a loaner, or because your primary ride is out of commission, as you basically need to do a mini bleed before each time you use the bike. In my experience, the equivalent mineral oil brake would still be working fine after sitting in that same environment for the same period of time.
You really know your stuff though, and it sounds like you are attuned to some issues associated with long term use of mineral oil that I am not, possibly related to more intense use cases, so what's the deal? What specific problems occur to mineral oil brakes that a switch to DOT would remedy?
With the assumption that brakes have to be bled often, which is the case for 90% of MTB brakes, the cons of mineral oil go away. That said, I've found mineral oils break down with heat much more readily. This is obviously tied to more extreme use cases like bike park of course. The other issue is actually moisture related. If you do get water in your brake lines somehow, DOT absorbs it and the boiling point drops a little. Meanwhile mineral oil does not absorb it and, with water being denser, it settles in the caliper and the boiling point is essentially converted to that of water. But the brakes should be sealed well enough that water doesn't really get in there. I've seen a Shimano brake where the caliper was entirely full of water due to a hole in the membrane, though.
There are a lot of possible ways to add a layer of insulation to brake pistons. In theory you could come up with an insert with low thermal conductivity and high contact resistance between it and the piston body. The latter being a little more difficult since pressure on an interface decreases contact resistance and brake pressures are fairly extreme.
There are a lot of possible ways to add a layer of insulation to brake pistons. In theory you could come up with an insert with...
There are a lot of possible ways to add a layer of insulation to brake pistons. In theory you could come up with an insert with low thermal conductivity and high contact resistance between it and the piston body. The latter being a little more difficult since pressure on an interface decreases contact resistance and brake pressures are fairly extreme.
Couldn’t you build the heat break into your pad backing?
A thin G10 strip or something.
Or do you need the airflow on the back of the pad?
Couldn’t you build the heat break into your pad backing?
A thin G10 strip or something.
Or do you need the airflow on the back of the pad?
Adding a strip would certainly help, however the heat flux is inversely proportional to the thickness of the material so thinner buys you less. Finned pads really are a good idea cost aside.
How about filling stainless steel pistons with a high temp epoxy and inset a neodymium magnet before it cures? That way you can have ease of...
How about filling stainless steel pistons with a high temp epoxy and inset a neodymium magnet before it cures? That way you can have ease of manufacturing, good thermals and magnetic pistons
i could actually get some spare hopes piston and attempt something like that, i feel one of the best things on Magura's are the pistons, the magnet is just genius and i have no idea why others don't do it
any thoughts a piston like this one compared like before to the other options? it's 7075 with a magnet. also curious if the bare stainless are getting...
any thoughts a piston like this one compared like before to the other options? it's 7075 with a magnet.
also curious if the bare stainless are getting the fluid hotter than others why Trickstuff and Intend and Radic use them vs hope style with the phenolic insert to fill it or ceramic insert like Lewis.
I would avoid aluminum pistons like the plague. The thermal conductivity of aluminum is very high. I want to say like 4x that of stainless at...
I would avoid aluminum pistons like the plague. The thermal conductivity of aluminum is very high. I want to say like 4x that of stainless at least. Not what you want in a brake caliper.
Stainless with a phenolic insert works well too. Stainless pistons are just easier to make or source. Phenolic pistons are a very specific resin that is molded at rather high pressures and then ground to the right dimension. Requires specific machinery whereas a stainless piston can be made on any mill or lathe.
i had that feeling but don't have either the knowledge on the subject or have done testing of some sort, cheers for the tip and explanation
I would avoid aluminum pistons like the plague. The thermal conductivity of aluminum is very high. I want to say like 4x that of stainless at...
I would avoid aluminum pistons like the plague. The thermal conductivity of aluminum is very high. I want to say like 4x that of stainless at least. Not what you want in a brake caliper.
Stainless with a phenolic insert works well too. Stainless pistons are just easier to make or source. Phenolic pistons are a very specific resin that is molded at rather high pressures and then ground to the right dimension. Requires specific machinery whereas a stainless piston can be made on any mill or lathe.
i had that feeling but don't have either the knowledge on the subject or have done testing of some sort, cheers for the tip and explanation
2.3 TRP rotors and MTX pads feel great and are a quiet combo. Shortened the deadband while making the bite point and power management feel more refined.
I have used galfer greens in the past to make brakes more powerful and have a stronger bite point, I wouldn’t want those for mavens.
i could actually get some spare hopes piston and attempt something like that, i feel one of the best things on Magura's are the pistons, the...
i could actually get some spare hopes piston and attempt something like that, i feel one of the best things on Magura's are the pistons, the magnet is just genius and i have no idea why others don't do it
I’ve always wondered if they have a patent on it, but haven’t dug around enough to find one.
Did a quick search on patent under Magura name and didn't find any about the magnetic caliper piston but found the one for the quick connect system of the gustav pro.
What temperature do the pads get up to? Magnets get very unhappy above 200°C. You have to glue them to the piston. You have to have the surface for it, which means more contact area for the pad and more heat transfer. You have to have steel back plates for the pads (finned pads are thus a no go). There are probably some more reasons why magnets aren't the bees knees.
Correct, the Hopes lack feedback when the pads contact the rotor. There’s also a lot of physical lever movement required to go from say 10% to 60% brake force. I’m pretty sure this is just a limitation of physics when the master cylinder has a big mechanical advantage over the pistons and you don’t have a cam or link to change the movement ratio from the lever.
The mavens require far less lever travel to ramp up in brake force. This gives them an initial impression of being grabby and lacking modulation. After a few laps, you realize that they’re actually pretty communicative but you have to pay attention to the feel of lever pressure more than lever position.
A fun quirk of the Hope levers that someone pointed out to me and now I can’t not notice. The lever throw is slightly off axis from the handlebar.
This was my observation when I ran them, same thing with the Maximas. You don't get that sortof pressure on the lever when you pull it and the pads engage, it's there but it's a lot more subtle than most brakes.
I think it comes down to preference more than anything, the Intends have similar power to the above but provide that feedback, which is why I preferred them.
Like you said, it is preference at the end of the day and we are lucky to have so many good options nowadays. I prefer that softer bite point of Trickstuff Maxima brakes which is why I sold the Intend Trinity.
The quirk, is it present on all of them? Or is it a case of a bent master cylinder?
No, it’s just the way the Tech 4 lever is designed. The lever sits slightly above the centerline of the bar.
Yeah, I am inclined to agree with you regarding the heavier pull, and I don't understand why people don't seem to recognize that most levers have a return spring and these return springs vary wildly in the force they generate. I personally like a very light feeling free stroke, both for feel, and for fatigue reasons, and have thought about trying to swap springs in brakes with heavier springs fitted stock.
Part of it is the cam profile. It’s more aggressive to advance the pistons to contact the rotor sooner. How they get the pad retract they have with such massive pistons. But that does mean there’s less mechanical advantage over the spring.
another thing is also how easy those piston move, on my mt7 and on the hopes i mounted today you can push the pistons back with the tip of your finger, generally on codes and g2, they're hard as to push back, a bit less after the famous "massage", Mavens felt a bit softer to push back, again better after the massage.
One thing to keep in mind, though, is that the pistons don’t really physically slide against the seals when you squeeze the lever. The seals flex outward with the piston. The only sliding is to accommodate pad wear. Along with that, the seal grooves are cut to give the seals room to flex outward but not so much inward. This all makes it harder to gauge the resistance you’d feel due to seals. That said, I do think the seals likely take a little more force to deform than on a lot of brakes. My overall impression of the Mavens is that they are built to be powerful and reliable. That comes at the expense of weight and, at times, a stiffer feel. Whether or not the reliability is real is debatable, although I’ve found once set up they are pretty trouble-free. But from that standpoint I wish they were DOT.
On a side note the fact that pistons don’t really slide in the seals much to speak of is why the marketing angles of different piston materials giving the brakes a smoother feel are kind of nonsense. When there’s no relative motion, the seals and pistons have no idea what the coefficient of friction of that interface is.
I think the different material of pistons could be more to handle heat differently
Say a ceramic piston vs a stainless vs ergal
Wouldn’t know which one is better
For example Billet factory in Italy is making some 7075 ergal pistons for the hope v4 that are a tad longer to accommodate better the use of thinner rotors
I’m not sure how that would change the brakes given the stock pistons are steel with a sort f resin insert.
Also, why would you wish they were ( the Maven ) Dot vs a better Mineral then maxima? Like Bionol, gold hydraulic or Pluto line
DOT can be left unattended for longer. I think it would be cool to have brakes that are as reliable and low maintenance as car brakes and that would require DOT.
In regards to heat, ceramic and phenolic pistons are superior. Stainless with an insert is decent too if the insert material insulates well. Straight metal pistons have a noticeable negative impact on brake fluid temp even on trails that aren’t too crazy. Stainless pistons result in the brake fluid getting 10% hotter pretty much instantly.
any thoughts a piston like this one compared like before to the other options? it's 7075 with a magnet.![]()
also curious if the bare stainless are getting the fluid hotter than others why Trickstuff and Intend and Radic use them vs hope style with the phenolic insert to fill it or ceramic insert like Lewis.
One possible reason is they are cheaper and easier to achieve tolerances with.
Since there is only a small edge of the stainless piston that is touching the brake pad that mean heat transfer is mostly from the air pocket between the brake pad and the bottom of the stainless piston ? A solid stainless piston would fare much worse in terms of heat capacity and transfer ?
Even with a thin piston wall in contact with the pad there is still significantly more heat transfer than other materials. Hard to get convection to out weigh conduction when it comes to heat transfer. When we were developing brake calipers, we really wanted to do stainless pistons because it's much easier to make stainless pistons, but the numbers just don't agree. This was testing comparing the temperature of the caliper body with stainless pistons similar to what you've described and phenolic pistons. The track was up on Chuckanut so nothing crazy.
I would avoid aluminum pistons like the plague. The thermal conductivity of aluminum is very high. I want to say like 4x that of stainless at least. Not what you want in a brake caliper.
Stainless with a phenolic insert works well too. Stainless pistons are just easier to make or source. Phenolic pistons are a very specific resin that is molded at rather high pressures and then ground to the right dimension. Requires specific machinery whereas a stainless piston can be made on any mill or lathe.
What about a double walled piston where an internal cylinder interfaces with the pad, the outer with the seal and the only link between them is the back face of the piston. So you do not heat the oil via the cylinder sleeve, only via transfer along the inner wall into the inner face.
It'd be a PITA to make though.
How about filling stainless steel pistons with a high temp epoxy and inset a neodymium magnet before it cures? That way you can have ease of manufacturing, good thermals and magnetic pistons
I see what you mean if we are actually comparing brake maintenance requirements of a DOT car vs. a mineral oil bike but that is an apples and oranges comparison because...
The car is an open system, and the air space at the top of the reservoir can self adjust to accommodate for fluid volume growth due to moisture absorption.
In our bike brakes, which have a membrane sealed reservoir, with very little room to accommodate for fluid volume growth, my experience is that a DOT bike left unattended in garage or shed in a humid environment for a year or 2 will absorb enough moisture to exhibit signs of overfilling, and will either leak out the reservoir cap (causing corrosion of the controls) or not leak but auto-apply the brake. Either way, it is a real PITA if you have a bunch of bikes that see little use, and you want to grab one on short notice as a loaner, or because your primary ride is out of commission, as you basically need to do a mini bleed before each time you use the bike. In my experience, the equivalent mineral oil brake would still be working fine after sitting in that same environment for the same period of time.
You really know your stuff though, and it sounds like you are attuned to some issues associated with long term use of mineral oil that I am not, possibly related to more intense use cases, so what's the deal? What specific problems occur to mineral oil brakes that a switch to DOT would remedy?
With the assumption that brakes have to be bled often, which is the case for 90% of MTB brakes, the cons of mineral oil go away. That said, I've found mineral oils break down with heat much more readily. This is obviously tied to more extreme use cases like bike park of course. The other issue is actually moisture related. If you do get water in your brake lines somehow, DOT absorbs it and the boiling point drops a little. Meanwhile mineral oil does not absorb it and, with water being denser, it settles in the caliper and the boiling point is essentially converted to that of water. But the brakes should be sealed well enough that water doesn't really get in there. I've seen a Shimano brake where the caliper was entirely full of water due to a hole in the membrane, though.
There are a lot of possible ways to add a layer of insulation to brake pistons. In theory you could come up with an insert with low thermal conductivity and high contact resistance between it and the piston body. The latter being a little more difficult since pressure on an interface decreases contact resistance and brake pressures are fairly extreme.
Couldn’t you build the heat break into your pad backing?
A thin G10 strip or something.
Or do you need the airflow on the back of the pad?
Adding a strip would certainly help, however the heat flux is inversely proportional to the thickness of the material so thinner buys you less. Finned pads really are a good idea cost aside.
i could actually get some spare hopes piston and attempt something like that, i feel one of the best things on Magura's are the pistons, the magnet is just genius and i have no idea why others don't do it
i had that feeling but don't have either the knowledge on the subject or have done testing of some sort, cheers for the tip and explanation
i had that feeling but don't have either the knowledge on the subject or have done testing of some sort, cheers for the tip and explanation
Maven bronze “tune” update:
2.3 TRP rotors and MTX pads feel great and are a quiet combo. Shortened the deadband while making the bite point and power management feel more refined.
I have used galfer greens in the past to make brakes more powerful and have a stronger bite point, I wouldn’t want those for mavens.
I’ve always wondered if they have a patent on it, but haven’t dug around enough to find one.
Did a quick search on patent under Magura name and didn't find any about the magnetic caliper piston but found the one for the quick connect system of the gustav pro.
https://worldwide.espacenet.com/patent/search/family/086606047/publication/DE202023102367U1?q=DE202023102367U1
What temperature do the pads get up to? Magnets get very unhappy above 200°C. You have to glue them to the piston. You have to have the surface for it, which means more contact area for the pad and more heat transfer. You have to have steel back plates for the pads (finned pads are thus a no go). There are probably some more reasons why magnets aren't the bees knees.
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