Brake Pads Worn?

jkvt

Member
Hi,

I have about 450 miles on my Moscow Plus. When I took it out today and hit the rear brake, I felt, and heard, a weird random throbbing that I never felt before. It was noticeable when I gave the back brakes some pressure. If I just pressed them lightly everything would feel fine. Rotor seems on firm, as does the caliper. So, the next thing that came to my mind is maybe the brake pads are worn... or there is some contamination on the ones I have in there. Everything I read online shows a different lifetime on disc brake pads. Some say 500 miles, some say 2000 so I'm really not sure if they shot or nowhere near worn out. I use the bike always on the road. We have a few steep hills but I'm not on them too often. Any thoughts? This is the first bike I have had with disc brakes so I'm really not sure what to worry about and what to not worry about. If they might be worn any suggested replacements? Thanks!
 
You should be able to see pretty easily how worn down they are (either with or without removing the caliper to check). A bit of foreign matter stuck in your pads could cause the vibration/noise you describe as could a small piece of the pad becoming partly detached. A quick squirt of brake cleaner and/or compressed air may well solve the problem.
 

jkvt

Member
It was a little difficult because the rack I put on is in the way of getting a good view of them but I was able to see. I think the pads are ok. I used some rubbing alcohol and that may have made things better. Unfortunately before, when I tried to get the pin for the pads out to look at them, the pin head stripped a bit. Used the right size allen wrench but the pin went nowhere and the wrench turned. The metal for the pin is junk. Super soft. Guess I have some time to figure out what to do there though.
 

Sierratim

Well-Known Member
Pad life is dependant on your riding conditions. Flat trail rides get better pad life than rides in hilly areas. 2,000 miles isn't out or reason for flats, 500 miles wore out my first set of pads on our hills. An inspection will tell.

Your bike has the Tektro 350 brakes, correct? The pads can be removed for inspection and cleaning by first removing the wheel. I would suggest this approach rather than cleaning in place as the rotors and caliper can be contaminated by cleaners.

It's often recommended that pads be replaced when they are worn down to 1mm. This Park Tool video discusses this;

If the pads are comfortably over 1mm I'd suggest cleaning with alcohol, a light sanding and then wipe with acetone. Clean the rotors with alcohol and reassemble. Otherwise, install new pads. This will require reseating the caliper pistons. There are videos on this as well.
 

Sierratim

Well-Known Member
It was a little difficult because the rack I put on is in the way of getting a good view of them but I was able to see. I think the pads are ok. I used some rubbing alcohol and that may have made things better. Unfortunately before, when I tried to get the pin for the pads out to look at them, the pin head stripped a bit. Used the right size allen wrench but the pin went nowhere and the wrench turned. The metal for the pin is junk. Super soft. Guess I have some time to figure out what to do there though.
You can a similar diameter cotter pin to replace the screw that secured the pads in the caliper. Several models of calipers use cotter pins to start with.
 

jkvt

Member
Thanks! I like the idea of the cotter pin. I'll go that direction once I get the pin out of there. Looks like the original issue I had was just dirt or some other contamination. I ran some errands today for about 13-14 miles, after cleaning things some yesterday and the problem appears to be gone.
 

EnduroDad

New Member
Mechanical brakes, standard model. I burned through a set of pads in the rear pretty quickly, I live a couple miles up a steep hill so it's a hostile environment for brakes :)

I replaced the pads with the red ceramic Tektro P20.11 Bp69a pads. They're more durable but still burning through quickly. I'd guess 50% longer life than the organic pads. About the same performance and noise level.

I'm looking to upgrade the rear, or both bakes to hydraulic. The constant adjustments are driving me nuts!