loosening crank

mustchat

I have a Kona Kula Primo 2006 with Race Face Deus XC BB and cranks. It started off OK but now the cranks have started coming loose. I use an Allen key to nip it up and it's OK for a couple of hundred yards then it comes loose again and I get all the usual symptoms of play in the crank / chainrings.
Any ideas?

lordhelmet

use loctite 243, otherwise known as threadlock
http://www.bearingshopuk.co.uk/index.as ... EgodU1gC6g

its expensive so if you know anyone who's a fitter or works in engineering ask them to get you some

if not, try a local backstreet garage

dave_s

If it's the ISIS version of the Deus cranks I think it's a common problem because I had some RaceFace Prodigy DH cranks which did the same thing on the non-drive side.

Best thing to do is get a longer allen key and really apply some pressure rather than just nipping them up with a multi-tool allen key. That worked for me anyway.

Something like this allen key would give you the leverage or check with your LBS
http://www.chainreactioncycles.com/Mode ... odelID=136
http://www.chainreactioncycles.com/Mode ... elID=10208

You need the 8mm allen key obviously

John Stevenson

Usually a loose crank needs replacing. As it loosens, the taper, spline or whatever gets damaged by the loads from using it. No amount of fitting force or threadlock will compensate for the fact that two parts that are supposed to be a very close fit are no longer so.

Get a new crank, and tighten it to the recommended 30-50 ft-lbs. Borrow a torque wrench if necessary. You may be surprised just how much force this requires.

mustchat

Cheers for the tips guys.

I think I will try the loctite first then if that doesn't succeed then I'll try new crank and BB combination.

When I said nip it up, I was probably being a bit diplomatic, out on the trail you can only tighten it as much as a mukti tool will allow but back in the garage I loop a hefty ring spanner over the end of the allen key which gives me a good eight inches of leverage.