bonsai171

I'm running TRP Spyre calipers on my Warbird, and had some questions about disc brake maintenance. Do the pads need to be sanded down like rim brake pads? I got some brake fade today and have never done any sort of maintenance on them except for adjusting the cable a bit. Do the rotors need cleaning too?

Dave

rumrunn6

don't know myself but found some info on google searching "bicycle disk brake fade"

dwmckee

Brake fade could be from contaminated rotor or pads, glazed pads, pads near worn out, grit embedded in the pads, damaged cable or housing, getting them really, really hot, etc. Sanding the pads and cleaning the rotor with alcohol or brake cleaning fluid can help with the glazed or contaminated pads. If you have a lot of miles on it, like 2K+ your pads may just be worn to the point where they need to be replaced. Several cable adjustments may be a good indication that the pads are worn to the point that they need to be replaced.

bonsai171

Sounds like I might need to replace the pads, got almost 1,800 miles on this bike. Will probably clean and measure first, but it sounds like it's time.

Dave

msu2001la

I've never heard of any sort of maintenance being done to disc brake pads, other than the need to do some initial bedding when they're new (which is basically just doing a few hard stops on them).

Otherwise, just run 'em till their worn, then replace.

tdilf

I pull pads about 2x a year to check their wear (and clean if needed). The pads should last you a long time - I am on my second set of pads @ 8K on the gravel bike.

chaadster

Yeah, I’ve never heard of sanding disc pads as a maintenance routine, but then, I’ve never heard of sanding rim brake pads as a matter of routine either, so maybe I’ve been riding with the wrong crowd the past three decades…

Koyote

Have a look at them, first. Usually you can just eyeball them, though you may get a better view if you (or someone else) can squeeze the brake lever while examining them. If you do have to remove the pads to get a good look, it's an easy task. It's not rocket science: you'll know if there's enough pad remaining; if there is enough, then it's one (or more) of the things dwmckee mentioned.

FWIW, I replaced the front pads on my main gravel bike (which has seen a lot of long, steep, and dirty descents) at about 7k miles. On my other disc brake bike, I have not replaced any pads yet in almost 12k miles.

bonsai171

Took my front brake pads out today, and they were super dirty. The inside of the caliper is very dirty too, so I'm planning to clean both. I read somewhere the pads should measure 3mm thick including the metal. One pad is definitely good, but one pad is low, but only on one side (it was 2.9mm). Since the wear is uneven, the caliper is slightly out of alignment. If I fix the caliper and clean everything, can I reinstall the same pads?

Dave

dwmckee

If pads are that low I would just replace them. $20 and you do not have to worry again for 2K miles (YMMV of course). Some folks do get better mileage out of pads, especially if they do not ride a lot of hills or dusty/muddy areas. I have also seen folks get 500 miles on a set of pads. I'd stick with what the original pads are in there if you were happy with the braking. Clean the rotors when you replace the pads with brake cleaner or alcohol.

If you have done 2 - 3 cable adjustments as you indicate, then the pads are likely toast.

Braking force is diminished as the pads wear down (less heat dissipation ability) and if you wear down to metal-on-metal you are going to be replacing much more expensive rotors. Change 'em and forget about it. I would not worry about getting the last $3 out of your old set of pads. Life is too short; change the pads and ride without worries.

bonsai171

I ride a lot of gravel and some singletrack with this bike. Lately it has seen a fair amount of mud and water, so that probably doesn't help.

Do I need to take the rotors off the wheel to clean them? Bought some isopropyl alcohol and gloves to clean that up. Is a cue tip enough to clean the rotors? I've seen people go so far as to light their rotors and pads on fire to decontaminate them:

Dave

dwmckee

Huh? No need to light them up. Just a very clean cloth and several wipings with alcohol or brake cleaner. Do not touch the rotors or pads with your hands as even that can cause some contamination. There is a lot of bad advice mixed in with the good out there. The guy in the video cautions about touching brake parts with his hands also, then repeatedly touches the pads and rotor surface with his hands. No need to remove the rotor. We occasionally sand the pads or rotors when they are shiny and glazed. To sand them we put a SINGLE SHEET of about 150 grit sandpaper on a clean flat surface and rub the pads in a circle until the shininess is gone. That can improve braking and remove some contamination.

bonsai171

I saw the same thing in the video. Bought some Shimano B01S pads yesterday, and took my time cleaning, adjusting, and putting everything back together. The Shimano pads seem a lot nicer than the TRPs. The TRPs have a strong initial bite, but that's about it. The Shimano pads have more modulation, but are a little noisier. They don't squeal, just a little abrasive noise when they contact the rotor. Maybe it will go away with some use, but not bad at all. So far I've only taken it around the block, so maybe they'll quiet down with a little more mileage.

Dave

Polaris OBark

You don't need to take rotors off the wheel to clean them, and you absolutely don't need a flame-thrower for the pads. Normally you don't need to do anything for the pads, but a light sanding will often renew the surface to a pristine state if there has been some form of contamination.

Burning alcohol isn't going to be doing anything anyway. It doesn't get very hot.

chas58

oddly, cleaning the pads can make them worse. I had an LBS clean my pads - did a great job, but they just didn't stop the bike anymore.

AFAIK, this was a problem because it was done in the fall. For the next 4 months it was at or near freezing. It wasn't until spring came and I could heat them up enough to brake them in properly.

Moral of the story - that glazing on the pads/rotors is important. Sanding takes it off. Not a problem in warm weather once you seat them properly - but I was struggling all winter.

autonomy

A couple of points - I have TRP Spyres too. My pads are worn, unevenly, and I'm getting ready to replace them - just less than 3300 on the bike. Reportedly, the OEM pads in Spyres are a. fast-wearing b. kind of suck. I got a replacement set from Amazon by Corki. Haven't tried them yet but reviews are good and for $12 whatever, I'll try them out.
The Spyres are supposed to be self-adjusting and the caliper action is also dual-sided, so it shouldn't be a problem for you if one pad is worn slightly more than the other.

All of the maintenance I've done on my disc brakes was to clean with mineral spirits and occasionally lube pivot points.

dwmckee

Mineral Spirits are derived from petroleum and can leave an oily residue. I would use brake cleaner or alcohol as recommended by brake manufacturers.

FuelExnTCX

Clean the rotors with alcohol and if there is glazing on the pads use some ligt sand paper to sand them down.

mauricesnail 

it's been a minute but I remember the stock pads on spyres to be pretty low performing out of the box, I debated sanding the pads but a few months in I replaced them with aftermarket ones and didn't have to think about my brakes for a year or two

redlude97

Yep replace TRP pads with shimano B01S and be happy. No noise, low cost and good performance

dwmckee

Also, the TRP Hy/Rd and Spyre calipers work WAY better if you use compressionless housing (as they recommend).

Fentuz

I wouldn't put alcohol on the pads set them on fire... it is likely to affect the sintering and could lead the braking material cracking and delamination from the back plate.

it s better to brush with alcohol and a tooth bush to remove loose residus, rinse with water and then, dry it with air dryer or may be re-rince with alcohol and dry with air dryer for speed...