I love riding my bike. It’s a great way to exercise and get some fresh air, but sometimes I hate riding my bike. That’s because when I pull on the brakes to stop, they don’t work well. They feel spongy or just plain don’t stop me at all! What gives? Fortunately for riders everywhere, there are many possible explanations for this phenomenon—all of which can be easily tested by anyone with basic mechanical skills and a set of tools:
Pads worn out
If you are experiencing sticking brakes, the first thing to check is the brake pads. It’s possible that they have worn out and need to be replaced. If this is the case, you can use a brake pad wear gauge to check them out.
A brake pad wear gauge will typically have measurements on it so that you can determine when your brakes are worn out enough for replacement. You should replace your bicycle brake pads when they reach 75% of their original thickness or less, depending on what’s recommended by your bike’s manufacturer (and/or local laws).
Dirt and Road grime
In order for your bicycle brakes to function, the pistons need to be able to move freely. If you’re experiencing issues with your brakes, it’s likely that something has been wedged into the system and is preventing them from working properly. This could be dirt, grime or any type of debris on either side of the piston.
If you’ve been riding your bike for a while, it’s likely that some dirt and road grime has built up on your brake pads. When this happens, the pads stick to their corresponding shoes when you apply pressure to them. Not only does this make it harder for your brakes to work effectively, but it also increases the likelihood of damaging your wheel or rim if they lock up while riding.
To prevent this from happening (or at least reduce its frequency), make sure that you regularly wipe down all of the parts of your bicycle’s braking system using a wet rag and mild soap so that any dirt can be removed before it causes any damage. If there are any cracks in the rubberized coating on your tires or rims, then consider replacing them with new ones immediately. Otherwise it could lead them having less traction than usual against each other which would make stopping much harder than normal.
If your rotor is bent, it can cause the brake to stick. You need to check if this is the issue by using a straightedge and checking for gaps in your rotor that are more than three millimeters wide. If there’s a gap in the rotor, you’ll need to straighten it out before continuing with any other diagnosis. This can be done with a simple C-clamp and some patience.
Contaminated brake fluid
You can tell if your brake fluid is contaminated by its appearance. If it’s clear and doesn’t smell like anything, you’re probably good to go. If it looks dark or smells like chemicals, then you should probably change the fluid. If you’ve got disc brakes, check that all of your calipers are closed before riding for the first time after a fluid change—this prevents extra air from getting into the system (and makes sure that no old bits of contamination make their way back into production).
It can be a number of things. Test each of the above, and then visit your local bike shop for a tune up.