Left crank arm knackered

Hi all,

My left crank arm is gubbed. Got it tightened at a store but think it’s threaded as it’s coming loose every time it’s tightened.

It’s a chasewood (shitty mango bike brand) and I was wondering if I can just replace the left crank arm without replacing the entire crankset (I’m a bit short on funds ATM!)

Assuming it’s the same size, I can’t see why not?

Hard to say, but you probably need a new bottom bracket as well then.

A lot of bike shops will have a parts bin full of old slops that have been taken off other bikes, cranks are pretty common. If you go in and ask nicely, and you might have to spend some money, they will probably give you a crank for free.

Otherwise, post pictures/ beg here.

That’s a photo. The bottom bracket looks untouched and it’s jusy worn away the crank arm

1 Attachment

That’s pretty standard. You’ve been riding it with the crank bolt loose, and it’s flapped about and enlarged the hole. They’re easily replaced tho. Yours is a diamond hole, you’ll just need to check the crank length; it’ll be stamped on the inside just around the pedal hole. It’ll probably be 170 or 175mm. Think they retail at about £12-15, and most LBS’s should have an old one knocking about if you’re skint.

The bottom bracket axle will be fine. It’s steel, and the crank is aluminium and the crank will give first.