Sounds like it is time for a full bleed and new pads. Mine are superb, have been running them for two years at least.
XTR m9120 Lacking Power
Hi Everyone, I have a set of XTR Brakes with MTX pads and 203 Rotors that are lacking power both front and rear. The brakes are quite loud when contacting the rotors and struggle to lock the wheel without significant force on the lever. The brakes have good lever feel so I cleaned and sanded the pads and rotors with a proper bed-in, but the problem persists. Does anyone have any recommendations?
I have only ridden the brakes in freezing conditions to date, which could be causing the power issue, however when pulling the brakes in my house they are still quite loud with limited bite. When compared to a set of XT brakes on a different bike, they seem like a lemon.
I have only ridden the brakes in freezing conditions to date, which could be causing the power issue, however when pulling the brakes in my house they are still quite loud with limited bite. When compared to a set of XT brakes on a different bike, they seem like a lemon.
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Reds.Gold or red pads?
To me the levers feel great, I have only ever run SRAM brakes though.Sounds like it is time for a full bleed and new pads. Mine are superb, have been running them for two years at least.
new rotors or old rotors that had been used with different pads before?
I purchased the bike used, so likely used rotors.
I have the same set up. They have awesome stopping power, have you bed them in good yet? Those ceramic pads do need a little aggressive breaking before they bite.
Reds look to be organic, gold look to be sintered. IME, sintered is more bite and power all the time, despite what a few say.Reds.
Interesting, I have done about 10hrs of riding on them now after I re-surfaced them. Would have assumed they would have bedded in by now.I have the same set up. They have awesome stopping power, have you bed them in good yet? Those ceramic pads do need a little aggressive breaking before they bite.
pads could be contaminated with oil. Try a new pair of pads and see (i know, you have to spend)
Hydraulic brakes are alway frustrating. Its usually an oil in the pads or not bedded in pads problem in my experience. I rode my squeaky, weak front brake for 4 months after giving up because of spending hours doing all the troubleshooting to fix it. And eventually it got much better after time.
Try following the instructions for bedding in the pads (see instructions for your brakes/pads). It normally takes only a few minutes to do it correctly, you should feel the power come in ... just riding will not do it, more likely to create long term poor performance.Interesting, I have done about 10hrs of riding on them now after I re-surfaced them. Would have assumed they would have bedded in by now.
Also, if the disk or pad is contaminated (i.e. oil or brake fluid) then you will have nearly no power no matter what. A good clean would take care of that.
Just don't throw the old pads out until you've concluded this issue.pads could be contaminated with oil. Try a new pair of pads and see (i know, you have to spend)
Sounds like contamination, especially if the noise is a goose-like honking and it disappears or changes when the rotors are wet.
New pads and rotors time. Cleaning isn't a substitute if you want the brakes to work 100%.
New pads and rotors time. Cleaning isn't a substitute if you want the brakes to work 100%.
You do not neccesary need new rotors but cleaning with brake cleaner and new pads . There is no known method of cleaning of contaminated with oild pads it just don'r work- pure waste of timeSounds like contamination, especially if the noise is a goose-like honking and it disappears or changes when the rotors are wet.
New pads and rotors time. Cleaning isn't a substitute if you want the brakes to work 100%.
How much did you clean the rotors before installing new pads?I purchased the bike used, so likely used rotors.
If you're changing pad compounds, you either need to get fresh rotors (by far the easiest option) or you need to be extremely thorough about cleaning the old rotors.
You might be able to clean the pads from the contamination they've picked up from the rotors (and possibly elsewhere) but doing so is probably going to require torching the pads. Fresh pads will also be the easier solution.
If you know the bleed is good and clamping force is working then most likely pad or rotor issue as others have indicated.
Take your pads out, spray with iso alcohol, rub the pads (braking surface) together until they feel smooth again. Re-spray wipe thoroughly.
Inspect the pads closely, sometimes organic pads get cooked and they are never the same again, you will see cracking.
Clean caliper with iso alcohol.
Take a sanding block and resurface your rotors, I use a medium grit like 150 or 120. Easiest to do this with rotor off. If you do it on the bike take a small block to press against the back for support and use the sanding block on the other side. I like to so this in a cross hatch pattern. XXXX
Clean with iso alcohol.
Re-assemble. If problem persists change out pads (try different brand like OEM). If problem persists change out rotor.
/2centsoff/
Take your pads out, spray with iso alcohol, rub the pads (braking surface) together until they feel smooth again. Re-spray wipe thoroughly.
Inspect the pads closely, sometimes organic pads get cooked and they are never the same again, you will see cracking.
Clean caliper with iso alcohol.
Take a sanding block and resurface your rotors, I use a medium grit like 150 or 120. Easiest to do this with rotor off. If you do it on the bike take a small block to press against the back for support and use the sanding block on the other side. I like to so this in a cross hatch pattern. XXXX
Clean with iso alcohol.
Re-assemble. If problem persists change out pads (try different brand like OEM). If problem persists change out rotor.
/2centsoff/
Sounds like everyone's opinion of 100% working brakes differs...
I've never ridden another bike with brakes that feel as good as mine (any of my bikes, any of the brake models and brands. Apart from SRAM Guides, they are just total ****). Perhaps my zero tolerance to contamination is a factor in this.
Here's something to consider. How do you season a pan, to make it non stick? With oil and moderate heat. What does a seasoned pan have in common with a contaminated rotor? The rotor also has oil on it, and gets heated up to a moderate temperature.
That oil isn't coming off in a hurry...
Contaminate either the pads or rotor, then use the brake, and they transfer oil between themselves - and they are then both only fit for the bin if you want properly functioning brakes.
Swapping only pads or rotor immediately contaminates the new component, and you are back to square one.
I've never ridden another bike with brakes that feel as good as mine (any of my bikes, any of the brake models and brands. Apart from SRAM Guides, they are just total ****). Perhaps my zero tolerance to contamination is a factor in this.
Here's something to consider. How do you season a pan, to make it non stick? With oil and moderate heat. What does a seasoned pan have in common with a contaminated rotor? The rotor also has oil on it, and gets heated up to a moderate temperature.
That oil isn't coming off in a hurry...
Contaminate either the pads or rotor, then use the brake, and they transfer oil between themselves - and they are then both only fit for the bin if you want properly functioning brakes.
Swapping only pads or rotor immediately contaminates the new component, and you are back to square one.
I don't agree. If you use proper methods you can always get them clean again. Washing rotor and torching pads burns the oil off every time
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