>>1157076>How to fix this?Assuming right is rear (back), your pads are probably worn.
Check if they need replacement, if not just adjust them.
If that doesn't help see if your cable routing is correct (no S bends) and consider upgrading to compressionless brake cable housing (like Jagwire).
Just DONT use derailleur housing. It doesn't have reinforcement to stop it from exploding under brake cable forces.
In addition I've found that on some bikes the cable posts are placed so badly that running full length cable from lever to rear caliper works better than the designed 2..3 sections.
