My bicycle is making a grinding noise when I pedal. What could it be and how can it be fixed? - Quora
![Bike makes knocking noise only when pedaling. The cassette cogs have some grooves on them. Is this normal or the cassette is defective? : r/bikewrench Bike makes knocking noise only when pedaling. The cassette cogs have some grooves on them. Is this normal or the cassette is defective? : r/bikewrench](https://i.redd.it/kzrb6cvyqmc51.jpg)
Bike makes knocking noise only when pedaling. The cassette cogs have some grooves on them. Is this normal or the cassette is defective? : r/bikewrench
![Bike makes a clicking sound when I push down on the pedals, found this thing touching the chain. Is it an issue? What should I do? : r/bikewrench Bike makes a clicking sound when I push down on the pedals, found this thing touching the chain. Is it an issue? What should I do? : r/bikewrench](https://i.redd.it/4im6kusquiz81.jpg)