Author Topic: Moving crank (Read 615 times)

Voodoocars · « **on:** June 11, 2007, 10:08 PM »

Anyone got any ideas on how to stop my one piece cranks moving and clunking between the threads of the crank and bearing cones.The locknut is as tight as I dare get it without it jumping threads.Its doin' my head in! Its almost like the cones are too big.This is the same on my Mongoose and my Diamond Back.Cheers, Ian.

Dark Diggler · « **Reply #1 on:** June 12, 2007, 07:03 AM »

Sounds like you need some spacers, but knowing what the cranks are and a picture or two will be usefull for diagnosis

Voodoocars · « **Reply #2 on:** June 12, 2007, 07:32 AM »

No, it doesnt need spacers- its like the threads on the adjusting cone and lock nut are just a slack fit.They are both normal american fit one piece crancks with unsealed berings.Bottom thread limit on the crank and top thread limit inside the cone probably.I'm going to try out different cones.I dont remember having this sort of problen BITD.

pickle · « **Reply #3 on:** June 12, 2007, 10:40 AM »

what crank is it? Sugino? Mongoose? Takagi? what BB is it? Odosey? DB? To be honest i've never had a problem with 1 piece cranks and non sealed BB but without details it's very hard to make a diagnosis mate??

Maybe you've got the wrong thread TPI (?) for the crank?? a Mongoose crank has to have a mongoose BB (i think) $:-\$

Get a few piccies up mate......someone will be able to put there finger straight on it then mate

theRuler · « **Reply #4 on:** June 12, 2007, 10:58 AM »

what pickle said -

some mongoose bb's/cranks have a different thread to normal 1pc's

also make sure your bearings aint in the wrong way around

crazy foool · « **Reply #5 on:** June 12, 2007, 07:40 PM »

backwards bearings sound right, make sure the cage is in the cup with the bearings facing out

Voodoocars · « **Reply #6 on:** June 12, 2007, 09:52 PM »

One is a mongoose with mongoose BB and one is a diamond back with diamond back BB.My other bike with a GT crank and diamond back BB has no trouble.Of course the bearings are in the right way round! It seems to me to be poor tolerances on threads.A friend of mine who runs a bike shop agrees- its not aerospace manufacturing,but mass produced forged cranks and bearing cones.Anyway, I've solved the problem.I just put an extra lock nut on to solidly clamp it.Seems to have done the trick. Ian