Noises coming from the drivetrain are very common, and could have a number of causes.

Diagnose the noise your bike is making

Constant grinding noise could be chain rubbing the front derailleur: If you’re chain is rubbing on the front derailleur then the noise will be constant as long as you’re in the big chainring. Jump off the bike and spin the pedal, if this is the cause you’ll see the chain very close to the piece of metal that shifts it between chianrings.

Either the front derailleur needs adjusting, in which case follow this guide, or by your derailleur is bent. This will be apparent by eye – you can bend it back yourself, but be very, very gentle-  and if you’re at all concerned, ask your local workshop for help.

Clunking when changing gears could be rear gears in need of indexing:  This noise will become familiar once you’re used it it – it will only happen when you try to shift, and will be a series of clunks and winges from the chain, which will probably then fail to move into the next gear as requested – in this case, the rear derailleur needs adjusting.

Clattering could be a loose cassette: If this is the case, you’ll notice a clattering when you ride over uneven surfaces. This is easy to spot – grab hold of the cassette, and wiggle the cogs left and right – they shouldn’t move. If they do, then nip to a workshop to have it tightened, unless you have a cassette tool and chain whip.

Chain is just really dirty: A dirty chain will be clunks and inefficient when shifting – if this is the case, follow our chain cleaning guide.