Rob Gartzman, Full Cycle Mechanic and Senior Suspension Technician, answers one of the most commonly asked questions.
Squealing brakes are not usually a bad thing. For one, at least you know your brakes are working. However, it may be really annoying. There are a few differentreasons why brakes squeal. Some are easy fixes, others require a little more sleuthing. Either way, we’ll help you on the road to quiet brakes.
Easy Fixes for Rim & Disc Brakes
Often, brakes squeal because some sort of contaminant got onto the braking surface. This is true for both rim brakes (which includes road bikes, v-brakes, and cantilever brakes) and disc brakes. Especially when it’s wet the oils on the ground can make their way to the bike and cause the brakes to squeal as a result. It only takes a little bit of oil contamination to cause squealing. The good news is that this is a pretty easy fix.
The best way to fix squealing from contamination is to clean the braking surface. For rim brakes I would recommend cleaning the rim and brake pads with Simple Green or Clean Streak. Clean Streak is more powerful if the contamination is really bad. It may take cleaning the braking surface a few times before it is really clean and stops squealing. For disc brakes I would just recommend using Clean Streak. Spray some Clean Streak onto a very clean towel and then wipe down the rotor with it until there is no more black residue on the rag. You should also be careful not to touch the rotor with your fingers because the natural oils on your hands can cause contamination as well. Disc brakes are a little more sensitive and if cleaning the rotor does not fix the problem you may need new pads as well. However, make sure to clean the rotor again before installing the new pads.
Slightly trickier fixes for rim brakes
The most common reason for a brake squeal on a rim brake is that the brake is vibrating while it is braking. This can happen for a number of different reasons but there are some tricks that we have to fix this problem. We would first try to “toe in” the brake pads, which means the front of the pad will touch the rim before the rear of the pad. If that doesn’t work we may reverse “toe” the pad. Usually that will fix the problem but it could also require further investigation.
Sometimes the pad compound is not ideal for the braking surface of the rim and replacing the pads can also fix the problem. In the end if none of these solutions work, replacing the brakes is always an option for rim brakes.
Even trickier fixes for disc brakes
For a disc brake squeal there is a lot more that goes into squealing brakes, and sometimes the problem is beyond the scope of what can be easily fixed in a bike shop. The caliper and rotor need to be lined up perfectly for the brake to work right, and sometimes the manufacturer needs to be called in for warranty or replacement parts. Also, the frame alignment needs to be correct for the brakes to work properly – a dented or bent frame can cause brakes to be misaligned and therefore squeal. These issues are not always ones that can be easily solved.
The final word
If you are having brake squealing issues, first try cleaning the braking surface to save yourself a trip. If that doesn’t work, bring your bike in and we will help you find a solution that works even if the problem goes beyond cleaning the braking surfaces.
Rob Gartzman has been repairing bikes since he was 14 and working as a bike mechanic since 1999. He currently is the Senior Suspension Technician at Full Cycle on Pearl St, while pursing a business degree at CU.
To schedule your brake service, call your local Full Cycle service department:
Pearl St: 303-440-1002
On the Hill: 303-440-7771