cranks loose but the bolt is tight
 

Hi my trek cranks are loose but the boltis tight can feel them moving when pedaling how do i fix that? Will i hurt anything by ridiing it with them loose? Is it time for a new bb.? tia

Sounds like a square taper crank. Riding with it loose just makes it worse. Its actually the crank that is shot, wear on the inside of the crank makes it loose. Usually caused by a loose bolt allowing the crank to move. 'Ya need a new crank. Note as well, the square taper shaft is steel, the crank is aluminum. Crank loses in those situations.

Okay thnx ill be getting new cranks soon i hope.

Update went to my lbs yeasterday morning and the guy told me that my spindle is moving and not the ctlranks how do i fix that?

Need more info: is it a cartridge bottom bracket? Is it square taper? Maybe some photos?

What does the guy at the LBS say?

Unless you have the tools to get the crank off and the tools to tighten the bottom bracket, why not have the shop do it ??

Cheap bikes often have non-cartridge bearings. Instead they have a fixed cup, & an adjustable cup with a lock ring. The adjustment likely needs to be revisited.

The exact tools needed will vary depending on the bottom bracket you have. https://www.parktool.com/en-us/categ...bottom-bracket

Probably HCW-4, or HCW-5, a pin spanner of some variety and maybe a crescent wrench.

For a simple adjustment you might need to remove the non-drive-side crank arm to gain access. CCP-7 is a good tool. For a complete overhaul/rebuild, you'd definitely need to remove both crankarms.

The adjustment is an easy 2 minute job. But for a one-off job, a bike shop is cheaper than the tools.

And if it is an inexpensive btm bracket, the shop could install a better one, so future problems might be avoided.

Yes square tapper bb