Nerding out on Brakes shall we? Not another tech deraliment

12/23/2024 12:22am

Hey guys, 

I'm having issues with my front brake lately but cannot understand why..

So I'm riding for the past 15 years, and since 2 months it seems that my front pads are glazing. I've be using trickstuff power one since 4 years and it has never happened to me.

The only thing that has changed is the disk, it's a TRP RS05E with 2.3m thick. Before that I was using Hope floating disk. So, could they be the culprit here ?

The only other possibility is that the pads are contaminated but I've NEVER contamined any pads... 

The first time it happened, I was guessing that maybe the pads were contaminated while the bike was on the bike rack (I could have drove on oil on the road). But two times in 2 months ?! 

I'm not completly sure there are glazed, but they are shinny. Also as I noticed the lack of power on my ride yesterday, I've tried to remove the pads and "sand" them using rocks and loam... At first the brake was more powerfull but it fastly became weak. Putting some backup pads (Intend white magic) and after a few miles, the brake was performing as it should.

I've also check, the caliper does not seem to leak at the pistons.

Correct me if I'm wrong but glazing happen when the pads are to hot no ? So I cannot understand why the bigger disk (2.3 instead of 1.8 - even if they are floatting) would make them glaze ?

There is something happening here but I don't understand what !

Evil96
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Portogruaro, VE, IT
12/23/2024 12:47am
petoulachi wrote:
Hey guys, I'm having issues with my front brake lately but cannot understand why..So I'm riding for the past 15 years, and since 2 months it seems...

Hey guys, 

I'm having issues with my front brake lately but cannot understand why..

So I'm riding for the past 15 years, and since 2 months it seems that my front pads are glazing. I've be using trickstuff power one since 4 years and it has never happened to me.

The only thing that has changed is the disk, it's a TRP RS05E with 2.3m thick. Before that I was using Hope floating disk. So, could they be the culprit here ?

The only other possibility is that the pads are contaminated but I've NEVER contamined any pads... 

The first time it happened, I was guessing that maybe the pads were contaminated while the bike was on the bike rack (I could have drove on oil on the road). But two times in 2 months ?! 

I'm not completly sure there are glazed, but they are shinny. Also as I noticed the lack of power on my ride yesterday, I've tried to remove the pads and "sand" them using rocks and loam... At first the brake was more powerfull but it fastly became weak. Putting some backup pads (Intend white magic) and after a few miles, the brake was performing as it should.

I've also check, the caliper does not seem to leak at the pistons.

Correct me if I'm wrong but glazing happen when the pads are to hot no ? So I cannot understand why the bigger disk (2.3 instead of 1.8 - even if they are floatting) would make them glaze ?

There is something happening here but I don't understand what !

Given that i turned my rotors blue on those pads and they didn't missed a beat i thought it was impossible to glaze them, and i hope it's not a rotor related issue as those rs05 are the ones i bought for my new brakeset.

as far as i know pads glaze when can't cope with the heat and basically cook, same rotor but with the white magic and it's all good? How's the rotor surface?

12/23/2024 1:09am

Yeah I forgot to mention that the disk does not appears blue at all, no sign of overheat. It's really weird

Dogboy
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Location
Chapel Hill, NC, USA
12/23/2024 4:04am
petoulachi wrote:
Hey guys, I'm having issues with my front brake lately but cannot understand why..So I'm riding for the past 15 years, and since 2 months it seems...

Hey guys, 

I'm having issues with my front brake lately but cannot understand why..

So I'm riding for the past 15 years, and since 2 months it seems that my front pads are glazing. I've be using trickstuff power one since 4 years and it has never happened to me.

The only thing that has changed is the disk, it's a TRP RS05E with 2.3m thick. Before that I was using Hope floating disk. So, could they be the culprit here ?

The only other possibility is that the pads are contaminated but I've NEVER contamined any pads... 

The first time it happened, I was guessing that maybe the pads were contaminated while the bike was on the bike rack (I could have drove on oil on the road). But two times in 2 months ?! 

I'm not completly sure there are glazed, but they are shinny. Also as I noticed the lack of power on my ride yesterday, I've tried to remove the pads and "sand" them using rocks and loam... At first the brake was more powerfull but it fastly became weak. Putting some backup pads (Intend white magic) and after a few miles, the brake was performing as it should.

I've also check, the caliper does not seem to leak at the pistons.

Correct me if I'm wrong but glazing happen when the pads are to hot no ? So I cannot understand why the bigger disk (2.3 instead of 1.8 - even if they are floatting) would make them glaze ?

There is something happening here but I don't understand what !

Sounds like contaminated pads. I'm extremely careful with my brakes and it occasionally happens with no obvious cause.

HexonJuan
Posts
408
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Location
USA
12/23/2024 7:59am
petoulachi wrote:
Hey guys, I'm having issues with my front brake lately but cannot understand why..So I'm riding for the past 15 years, and since 2 months it seems...

Hey guys, 

I'm having issues with my front brake lately but cannot understand why..

So I'm riding for the past 15 years, and since 2 months it seems that my front pads are glazing. I've be using trickstuff power one since 4 years and it has never happened to me.

The only thing that has changed is the disk, it's a TRP RS05E with 2.3m thick. Before that I was using Hope floating disk. So, could they be the culprit here ?

The only other possibility is that the pads are contaminated but I've NEVER contamined any pads... 

The first time it happened, I was guessing that maybe the pads were contaminated while the bike was on the bike rack (I could have drove on oil on the road). But two times in 2 months ?! 

I'm not completly sure there are glazed, but they are shinny. Also as I noticed the lack of power on my ride yesterday, I've tried to remove the pads and "sand" them using rocks and loam... At first the brake was more powerfull but it fastly became weak. Putting some backup pads (Intend white magic) and after a few miles, the brake was performing as it should.

I've also check, the caliper does not seem to leak at the pistons.

Correct me if I'm wrong but glazing happen when the pads are to hot no ? So I cannot understand why the bigger disk (2.3 instead of 1.8 - even if they are floatting) would make them glaze ?

There is something happening here but I don't understand what !

Sounds like contaminated pads. What make and model of brakes are they, how long have you had em, and when was the last time you bled/serviced them?

12/23/2024 9:00am

I'm on Intend Trinity brakes, bleed is ok. The pads have 100 miles as I've just replaced the other faultly pads as I was thinking about contamination.

I know it could happens but it has never happened to me in 15 years, and now 2 in 2 months ? this is weird.

 

Dogboy
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Location
Chapel Hill, NC, USA
12/23/2024 9:06am
petoulachi wrote:
I'm on Intend Trinity brakes, bleed is ok. The pads have 100 miles as I've just replaced the other faultly pads as I was thinking about...

I'm on Intend Trinity brakes, bleed is ok. The pads have 100 miles as I've just replaced the other faultly pads as I was thinking about contamination.

I know it could happens but it has never happened to me in 15 years, and now 2 in 2 months ? this is weird.

 

If it's never happened to you in 15 years consider yourself extremely lucky. I work in a shop and see them all the time - it's why I'm so meticulous with my own brakes and it still happens occasionally. 

2
12/23/2024 1:25pm Edited Date/Time 12/23/2024 1:27pm

The tiniest amount of contamination will significantly reduce braking power. Maybe there is a tiny leak from oil on the pisons? Or some cleaning spray? Try to degrease the caliper and disk with isopropyl alcohol and try new pads. And break them in properly. 

I also once got contamination over night after I mobilized the pistons and put  a bit too much oil on the side of the pistons. Or my brother once was frying steaks in the campervan and all the pads on the bikes in the rear compartment were contaminated. Usually the brakes squeal similar to when its raining when contaminated although its dry. 

12/24/2024 12:44am Edited Date/Time 12/24/2024 12:44am

I agree I have to double check if there is not a leak at the pistons, but beside that I could not believe I did contaminated my pads two times in a row.

 

There absolutely no chance that the new disk could glaze the pads ?

Thanks !

DServy
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Location
Jackson, WY, USA
12/24/2024 6:17am
tabletop84 wrote:
The tiniest amount of contamination will significantly reduce braking power. Maybe there is a tiny leak from oil on the pisons? Or some cleaning spray? Try...

The tiniest amount of contamination will significantly reduce braking power. Maybe there is a tiny leak from oil on the pisons? Or some cleaning spray? Try to degrease the caliper and disk with isopropyl alcohol and try new pads. And break them in properly. 

I also once got contamination over night after I mobilized the pistons and put  a bit too much oil on the side of the pistons. Or my brother once was frying steaks in the campervan and all the pads on the bikes in the rear compartment were contaminated. Usually the brakes squeal similar to when its raining when contaminated although its dry. 

Ah yes, the perpetual fear of brake contamination.

Does anyone use any brake cleaner to try to fix some of this issue? I have used https://www.finishlineusa.com/products/bicycle-degreasers/bicycle-disc-brake-cleaner in the past with some pretty meh results, and I've never really got rotor/pad sanding to work with any sort of consistency. 

It would be nice to be able to save a rotor/pad combo every once and a while. 

 

12/24/2024 7:17am

I only use brake cleaner for the disc as its more aggressive than isopropyl alcohol. But I always could save the disc. Only had to throw away the pads. 

Splayleg
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Los Gatos, CA, USA
12/24/2024 7:40am
petoulachi wrote:
Hey guys, I'm having issues with my front brake lately but cannot understand why..So I'm riding for the past 15 years, and since 2 months it seems...

Hey guys, 

I'm having issues with my front brake lately but cannot understand why..

So I'm riding for the past 15 years, and since 2 months it seems that my front pads are glazing. I've be using trickstuff power one since 4 years and it has never happened to me.

The only thing that has changed is the disk, it's a TRP RS05E with 2.3m thick. Before that I was using Hope floating disk. So, could they be the culprit here ?

The only other possibility is that the pads are contaminated but I've NEVER contamined any pads... 

The first time it happened, I was guessing that maybe the pads were contaminated while the bike was on the bike rack (I could have drove on oil on the road). But two times in 2 months ?! 

I'm not completly sure there are glazed, but they are shinny. Also as I noticed the lack of power on my ride yesterday, I've tried to remove the pads and "sand" them using rocks and loam... At first the brake was more powerfull but it fastly became weak. Putting some backup pads (Intend white magic) and after a few miles, the brake was performing as it should.

I've also check, the caliper does not seem to leak at the pistons.

Correct me if I'm wrong but glazing happen when the pads are to hot no ? So I cannot understand why the bigger disk (2.3 instead of 1.8 - even if they are floatting) would make them glaze ?

There is something happening here but I don't understand what !

Galfer makes some great cheap 2.0 rotors. Seems like you are getting heat build/contact from the 2.3

12/24/2024 9:38am

I was told by MTX if you have contamination to use acetone and its a bit more aggressive than isopropyl.  I believe you can try that on the pads too and sand them down as well, but don't quote me on that.

From MTX, for rotors: 
Wear gloves and begin the following process:
Remove your rotors - spray them clean with an automotive brake cleaner or isopropyl alcohol. Wipe the rotors dry before the brake cleaner dries.
Grab some 80 or 100 grit sandpaper and sand both sides in fairly straight lines, by hand, aggressively. We want to get the factory crosshatch pattern back into the surface essentially creating a new, rough surface for the brake pad to bed into and bite down on. *Rotors are made from hardened stainless steel - you will-not damage or remove any material of the rotor, what-so-ever when sanding by-hand. You’re literally just scratching the surface to create a new “bite point” for the rotor and pad surface.
Spray the rotors with the brake cleaner or alcohol again, and wipe them down before it dries.
Lightly sand the brake pads (if they are used) - it'll take less than a few seconds to get them to look like new again. This resets the pads (as long as they have not been exposed to any oils or contaminants).
1
12/24/2024 1:55pm

I use isopropyl alcohol and 80 to 180 grit emery paper/cloth (just depends what I have on hand).

For the pads, soapy water in the sink (plug in). Rub the pads against each other. Followed by just water, rubbing the pads together. Might take some rubbing (sometimes not long), but you know when they are done as the pads start gripping each other. 

 

Has always worked for me. 

1
Primoz
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SI
12/25/2024 10:08pm

Brake cleaner is a really strong solvent, for some things even stronger than acetone (cleaning an oil pan gasket sealer works really well while acetone hardly does anything). No worries about the strength of it. 

HexonJuan
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Location
USA
12/27/2024 6:25am
petoulachi wrote:
Hey guys, I'm having issues with my front brake lately but cannot understand why..So I'm riding for the past 15 years, and since 2 months it seems...

Hey guys, 

I'm having issues with my front brake lately but cannot understand why..

So I'm riding for the past 15 years, and since 2 months it seems that my front pads are glazing. I've be using trickstuff power one since 4 years and it has never happened to me.

The only thing that has changed is the disk, it's a TRP RS05E with 2.3m thick. Before that I was using Hope floating disk. So, could they be the culprit here ?

The only other possibility is that the pads are contaminated but I've NEVER contamined any pads... 

The first time it happened, I was guessing that maybe the pads were contaminated while the bike was on the bike rack (I could have drove on oil on the road). But two times in 2 months ?! 

I'm not completly sure there are glazed, but they are shinny. Also as I noticed the lack of power on my ride yesterday, I've tried to remove the pads and "sand" them using rocks and loam... At first the brake was more powerfull but it fastly became weak. Putting some backup pads (Intend white magic) and after a few miles, the brake was performing as it should.

I've also check, the caliper does not seem to leak at the pistons.

Correct me if I'm wrong but glazing happen when the pads are to hot no ? So I cannot understand why the bigger disk (2.3 instead of 1.8 - even if they are floatting) would make them glaze ?

There is something happening here but I don't understand what !

Agreed with the others about it sounding like contaminated pads. What make and model of brake are they, how old, and when and what was the last service on em? 

IME 'cleaning' pads after a contamination is a recipe for irritation. Pads are porous by nature, and any fluid that gets on em will seep into them during use. Cleaning removes the surface layer (and maybe some embedded) contaminant, and once the pads warm up the contaminant flows out to the braking surface, making the brake garbage again. Avoid the pratfall and pony up for new pads. Rotors can be cleaned without issue. I prefer contact cleaner or a strong isopropyl, 93% or better, as they leave less residue behind. A clean water wipe after isn't a bad idea either. 

1
j0lsrud
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NO
12/27/2024 7:23am

How about the good old gas burner for cleaning pads? Asking because fire is fun.

1
HexonJuan
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USA
12/27/2024 7:39am
j0lsrud wrote:

How about the good old gas burner for cleaning pads? Asking because fire is fun.

1. Semi mets/organics no go. You'll smoke the friction material in both (usually walnut shells believe it or not) while also smoking the adhesive used to hold the thing together and to the backing plate. Bad idea. Shucking corn = good, shucking pads = bad.

2. Sintered/ceramic. Never had luck with it. The problem always returned. I tried all the fixes I saw folx post, MAPP gas, stove top burner, broil the pads for an hour. Each ended up with a death grip to get the bike to slow. And noise. So much damn noise. The job that made me try all those wasn't glamorous, but it provided a lotta good insights. One of those was just to replace the pads when they're contaminated. No amount of fudgery is gonna bring em back to even 80% of their intended friction.

3
TheKaiser
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Storrs, CT, USA
12/28/2024 8:53am Edited Date/Time 12/28/2024 8:54am
Evil96 wrote:
Has anyone ever seen these?I’ve seen them in a custom build and got curious, never heard of the companyhttps://www.rideraicam.com/en/products/rgr-racing-brake-system/

Has anyone ever seen these?

I’ve seen them in a custom build and got curious, never heard of the company

https://www.rideraicam.com/en/products/rgr-racing-brake-system/

IMG 4771 0

No, I've never seen those before, and while we're talking about new MTB brake brands, I forget if we've already discussed these new HEL brakes earlier in this huge thread? https://www.bikemag.com/industry-news/hel-advocate-mountain-bike-brake

They claim some sort of special caliper fluid channel and piston design, but I'm unsure if that is just regular brake design that their marketing department is jazzing up as if it's unique.

1
TheKaiser
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12/28/2024 8:57am Edited Date/Time 12/28/2024 8:59am
tabletop84 wrote:
The tiniest amount of contamination will significantly reduce braking power. Maybe there is a tiny leak from oil on the pisons? Or some cleaning spray? Try...

The tiniest amount of contamination will significantly reduce braking power. Maybe there is a tiny leak from oil on the pisons? Or some cleaning spray? Try to degrease the caliper and disk with isopropyl alcohol and try new pads. And break them in properly. 

I also once got contamination over night after I mobilized the pistons and put  a bit too much oil on the side of the pistons. Or my brother once was frying steaks in the campervan and all the pads on the bikes in the rear compartment were contaminated. Usually the brakes squeal similar to when its raining when contaminated although its dry. 

That is a wild story about the steaks but I can totally see that happening after noticing little dots on my shirts whenever I'm cooking something in oil that sizzles, and seeing the little wet specks all over the stove area. That is a good thing to keep in mind for whenever I get back into the campervan life, as that could really ruin a trip, especially if you have limited time to ride and need to spend a lot of it fixing your brakes, or if you're in a rural area without the necessary replacement pads.

Evil96
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Portogruaro, VE, IT
12/28/2024 10:55am
TheKaiser wrote:
No, I've never seen those before, and while we're talking about new MTB brake brands, I forget if we've already discussed these new HEL brakes earlier...

No, I've never seen those before, and while we're talking about new MTB brake brands, I forget if we've already discussed these new HEL brakes earlier in this huge thread? https://www.bikemag.com/industry-news/hel-advocate-mountain-bike-brake

They claim some sort of special caliper fluid channel and piston design, but I'm unsure if that is just regular brake design that their marketing department is jazzing up as if it's unique.

By the numbers presented I think they will be nothing special honestly 

12/28/2024 1:44pm Edited Date/Time 12/28/2024 1:46pm
tabletop84 wrote:
The tiniest amount of contamination will significantly reduce braking power. Maybe there is a tiny leak from oil on the pisons? Or some cleaning spray? Try...

The tiniest amount of contamination will significantly reduce braking power. Maybe there is a tiny leak from oil on the pisons? Or some cleaning spray? Try to degrease the caliper and disk with isopropyl alcohol and try new pads. And break them in properly. 

I also once got contamination over night after I mobilized the pistons and put  a bit too much oil on the side of the pistons. Or my brother once was frying steaks in the campervan and all the pads on the bikes in the rear compartment were contaminated. Usually the brakes squeal similar to when its raining when contaminated although its dry. 

TheKaiser wrote:
That is a wild story about the steaks but I can totally see that happening after noticing little dots on my shirts whenever I'm cooking something...

That is a wild story about the steaks but I can totally see that happening after noticing little dots on my shirts whenever I'm cooking something in oil that sizzles, and seeing the little wet specks all over the stove area. That is a good thing to keep in mind for whenever I get back into the campervan life, as that could really ruin a trip, especially if you have limited time to ride and need to spend a lot of it fixing your brakes, or if you're in a rural area without the necessary replacement pads.

It happened. And you shouldn't really do that in a campervan anyway or it will smell really bad in no time. You should fry stuff outside or at least leave the side door open. But it was winter and he likes to cook...

I mean if you check thr extractor hood at home you'll notice that its covered in fat and in the campervan you usually don't have that and the heat makes little oil particles rising up in the air and they have to go somewhere. I also couldn't believe it at first but thank god I had extra pads. 

12/29/2024 12:14pm

I just installed my Radic Kaha brakes. I find that the rear pumps up pretty significantly (10mm). I've bled the brake perfectly to my knowledge, lubed the caliper pistons and tried pressurizing the system from the bleeding edge port etc. Is this due to the small orifices in the lever design or is there something I'm missing out on?

Jakub_G
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SK
12/30/2024 9:26am
I just installed my Radic Kaha brakes. I find that the rear pumps up pretty significantly (10mm). I've bled the brake perfectly to my knowledge, lubed...

I just installed my Radic Kaha brakes. I find that the rear pumps up pretty significantly (10mm). I've bled the brake perfectly to my knowledge, lubed the caliper pistons and tried pressurizing the system from the bleeding edge port etc. Is this due to the small orifices in the lever design or is there something I'm missing out on?

Your bleed is most likely not as perfect as you think it is.

AnttiH
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Tampere, FI
12/30/2024 9:37am
Jakub_G wrote:

Your bleed is most likely not as perfect as you think it is.

Do you have any tips for me?


I bled them like this:


-Removed from bike.

-Wound contact point adjuster almost all the way out (there’s no stop in the adjuster at the fully wound out point).


-Pushed fluid from caliper up to the lever.


-Cycled the fluid back and forth about 5 times.


-Pushed out piston against a 4mm hex wrench and repeated cycling fluid back and forth.


-Pushed pistons back in.


-Zip tied lever to bar.


-Carefully pulled a little vacuum to draw any residual air from caliper.


-Pushed fluid from caliper up to the lever while releasing the zip tied lever slowly.


-Removed caliper syringe.


-Did a lever bleed by tilting it around and pushing and pulling on the syringe.


-Added positive pressure before removing lever syringe.

yzedf
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Hebron, CT, USA
Fantasy
12/30/2024 10:25am
Jakub_G wrote:

Your bleed is most likely not as perfect as you think it is.

AnttiH wrote:
Do you have any tips for me?I bled them like this:-Removed from bike.-Wound contact point adjuster almost all the way out (there’s no stop in the...

Do you have any tips for me?


I bled them like this:


-Removed from bike.

-Wound contact point adjuster almost all the way out (there’s no stop in the adjuster at the fully wound out point).


-Pushed fluid from caliper up to the lever.


-Cycled the fluid back and forth about 5 times.


-Pushed out piston against a 4mm hex wrench and repeated cycling fluid back and forth.


-Pushed pistons back in.


-Zip tied lever to bar.


-Carefully pulled a little vacuum to draw any residual air from caliper.


-Pushed fluid from caliper up to the lever while releasing the zip tied lever slowly.


-Removed caliper syringe.


-Did a lever bleed by tilting it around and pushing and pulling on the syringe.


-Added positive pressure before removing lever syringe.

I have had good luck tapping on brake lines with a wrench while pushing/pulling fluid through the lines. 

Slavid666
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Location
Santa Rosa, CA, USA
12/30/2024 10:40am
Jakub_G wrote:

Your bleed is most likely not as perfect as you think it is.

AnttiH wrote:
Do you have any tips for me?I bled them like this:-Removed from bike.-Wound contact point adjuster almost all the way out (there’s no stop in the...

Do you have any tips for me?


I bled them like this:


-Removed from bike.

-Wound contact point adjuster almost all the way out (there’s no stop in the adjuster at the fully wound out point).


-Pushed fluid from caliper up to the lever.


-Cycled the fluid back and forth about 5 times.


-Pushed out piston against a 4mm hex wrench and repeated cycling fluid back and forth.


-Pushed pistons back in.


-Zip tied lever to bar.


-Carefully pulled a little vacuum to draw any residual air from caliper.


-Pushed fluid from caliper up to the lever while releasing the zip tied lever slowly.


-Removed caliper syringe.


-Did a lever bleed by tilting it around and pushing and pulling on the syringe.


-Added positive pressure before removing lever syringe.

Definitely a bleed issue... I've been on the new, with contact point adjustment, brakes for about 6 months now. If you are not degassing the fluid before doing the bleed, you should. I also use fresh fluid on every bleed, I dont re-use old, opened containers (assuming that you are using DOT) The lever is pretty good at trapping bubbles, and they can be a pain to get out. Once you have pushed fluid from the caliper to the lever, close the caliper and pull a good vacuum from the lever syringe. I made a "tool" that lets me pull the vacuum and not have to keep holding it, its a spacer made from an old extra-long socket that I cut a slot on with a die-grinder, been using it for years! Once you have the vacuum pulled you can move the lever body around and tap on it to force any bubbles up into the syringe. Once you get it, its good, but I I did a quick bleed on them when I got them and had a pretty big oh sh*t moment the first ride out when the front brake went to the bar halfway down the mountain... Once you get it they are solid. I will say they are probably one of the more difficult brakes to bleed of any modern disc brake IMO, but once you get them dialed they are one of the best brakes I've ever had the pleasure of riding. 

I also have found that its pretty important to bleed with the pads in while the brake is on the bike. It's in the instructions and I glossed over that when I first bled the brakes which could have been my problem. Ive found that there is a single position for my bike that magically helps to migrate bubbles to the lever, hanging front tire up in my bike storage system, so i bleed the brakes with the bike in that position in the stand. Once I learned that and re-bled them in that position I haven't had to touch them, 5+ months and lots of weekends on the lifts.

1
AnttiH
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Tampere, FI
12/30/2024 11:55am
Slavid666 wrote:
Definitely a bleed issue... I've been on the new, with contact point adjustment, brakes for about 6 months now. If you are not degassing the fluid...

Definitely a bleed issue... I've been on the new, with contact point adjustment, brakes for about 6 months now. If you are not degassing the fluid before doing the bleed, you should. I also use fresh fluid on every bleed, I dont re-use old, opened containers (assuming that you are using DOT) The lever is pretty good at trapping bubbles, and they can be a pain to get out. Once you have pushed fluid from the caliper to the lever, close the caliper and pull a good vacuum from the lever syringe. I made a "tool" that lets me pull the vacuum and not have to keep holding it, its a spacer made from an old extra-long socket that I cut a slot on with a die-grinder, been using it for years! Once you have the vacuum pulled you can move the lever body around and tap on it to force any bubbles up into the syringe. Once you get it, its good, but I I did a quick bleed on them when I got them and had a pretty big oh sh*t moment the first ride out when the front brake went to the bar halfway down the mountain... Once you get it they are solid. I will say they are probably one of the more difficult brakes to bleed of any modern disc brake IMO, but once you get them dialed they are one of the best brakes I've ever had the pleasure of riding. 

I also have found that its pretty important to bleed with the pads in while the brake is on the bike. It's in the instructions and I glossed over that when I first bled the brakes which could have been my problem. Ive found that there is a single position for my bike that magically helps to migrate bubbles to the lever, hanging front tire up in my bike storage system, so i bleed the brakes with the bike in that position in the stand. Once I learned that and re-bled them in that position I haven't had to touch them, 5+ months and lots of weekends on the lifts.

I’m running them with bionol so degassing won’t do me any favours afaik.

AnttiH
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Tampere, FI
12/30/2024 2:30pm Edited Date/Time 12/30/2024 2:32pm
Slavid666 wrote:
Definitely a bleed issue... I've been on the new, with contact point adjustment, brakes for about 6 months now. If you are not degassing the fluid...

Definitely a bleed issue... I've been on the new, with contact point adjustment, brakes for about 6 months now. If you are not degassing the fluid before doing the bleed, you should. I also use fresh fluid on every bleed, I dont re-use old, opened containers (assuming that you are using DOT) The lever is pretty good at trapping bubbles, and they can be a pain to get out. Once you have pushed fluid from the caliper to the lever, close the caliper and pull a good vacuum from the lever syringe. I made a "tool" that lets me pull the vacuum and not have to keep holding it, its a spacer made from an old extra-long socket that I cut a slot on with a die-grinder, been using it for years! Once you have the vacuum pulled you can move the lever body around and tap on it to force any bubbles up into the syringe. Once you get it, its good, but I I did a quick bleed on them when I got them and had a pretty big oh sh*t moment the first ride out when the front brake went to the bar halfway down the mountain... Once you get it they are solid. I will say they are probably one of the more difficult brakes to bleed of any modern disc brake IMO, but once you get them dialed they are one of the best brakes I've ever had the pleasure of riding. 

I also have found that its pretty important to bleed with the pads in while the brake is on the bike. It's in the instructions and I glossed over that when I first bled the brakes which could have been my problem. Ive found that there is a single position for my bike that magically helps to migrate bubbles to the lever, hanging front tire up in my bike storage system, so i bleed the brakes with the bike in that position in the stand. Once I learned that and re-bled them in that position I haven't had to touch them, 5+ months and lots of weekends on the lifts.

Also, what did you set the contact point adjustment to when bleeding them?


My current issues are:
Front brake reservoir membrane can’t handle pulling a vacuum. When I have a syringe connected to the lever and push positive pressure, it doesn’t leak from the vent hole. But if I pull on the syringe to create a vacuum, it sucks air in like crazy.


Rear brake can handle a vacuum but if I depress the lever while pulling the vacuum, it sucks air in just like the front brake.


The rear membrane leaked like crazy when I first bled it but removing and reinstalling the bladder seemed to fix it. I did the same to the front brake but it didn’t fix it.


Neither brake seems to leak from the master cylinder pistons and hose connections are all tight and not leaking.


I’m wondering if I have a bad set…

I truly wonder how components of this pricepoint can have these issues from new especially when they are hand built and tested.

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