Cranks not going on fully/enough

bg44097

So after a lot of work and effort I finally got my bike built, after my second ride the left hand crank arms square tapper connector literally shredded (side note, why did this happen?) Anyway after buying a cheap replacement from halfords... I put it on to find that the gap in between the bb and the cranks was 1cm+. I understand that it's supposed to have some space, but this seems unsafe to ride and I don't want to have to splash out on a 3rd crank arm. How do I fix this? am I doing something wrong? I'll attach a picture.

nicklouse

Looks like you have the wrong cranks for your bottom bracket.

Or wrong BB for your new cranks.

They need to be correct.

For that you need to know the axle length and the axle length required for the cranks.

bg44097

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19729844#p19729844]nicklouse[/url] wrote:

Looks like you have the wrong cranks for your bottom bracket.

Or wrong BB for your new cranks.

They need to be correct.

For that you need to know the axle length and the axle length required for the cranks.

no the cranks are for a 110mm bb, the right hand one go's on perfectly. This isn't the problem

cooldad

Square taper goes if it loosens, mainly on the non drive side because of the way it turns - unscrews the bolt.

Cheap ones especially.

Maybe cheap is why it doesn't fit, or what Nicklouse said.

The Rookie

Either the crank is duff or it's designed for a narrower axle.

If you have a wide (say 123mm) axle you do get a big gap by design anyway.

nicklouse

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19729845#p19729845]bg44097[/url] wrote:

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19729844#p19729844]nicklouse[/url] wrote:

Looks like you have the wrong cranks for your bottom bracket.

Or wrong BB for your new cranks.

They need to be correct.

For that you need to know the axle length and the axle length required for the cranks.

no the cranks are for a 110mm bb, the right hand one go's on perfectly. This isn't the problem

and the axle length is? and no axles are not positioned centerally in the BB.

cooldad

My commuter with cheap and nasty cranks - looks ok to me.

bg44097

I'll just file it a bit so it goes on a little better, after all this is only a temporary replacement. Ill be getting new ones at Christmas hopefully. Will some sort of screw sealant/adhesive stop the bolt from unscrewing? I can pick some up next weekend. for the mean time Ill carry a set of allen keys to make sure it's not coming loose.

penguin_of_death

It's because it's a generic replacement to work with as many options as possible, if its on and tight with no movement then its goo, the gap isn't a problem

The Rookie

If you file it you may as well just throw it away and save yourself the effort now, you'll never match the taper profile well enough to use them safely again.