Have i ruined my crank?

AC20030_1

Hi. I've have just installed a new sram red crank on my bike and when i was tightening up the nut it went loose just as i was about to stop tightening. The crank arm seems to be secured onto the bike but the bolt in the middle just spins in either direction. Have i ruined my crank arm from tightening it to hard? Is it safe to ride on for now? Any ideas how i could remove it when i need to? Thanks.

rake

dont ride it. sounds like youve stripped the threads from the alloy bolt.the crank will likely be ok being cromolly steel. put a new bolt in. you may have to drill the old one out, or glue an old allen key in the slot and pull while undoing.

ddraver

It's phenomonally easy to strip these as they re made so delicately in order to be light, try and get it out (it probably won't be that difficult but may be a bit of a faff) and then make your way to a friendly bike shop or Fisher (UK SRAM distributor). They really don't need much tightening, I found his out the hard way too

AC20030_1

Thanks guys. Took it down to my lbs and they have managed to remove the bolt. Fortunately it was just the bolt that threaded not the crank however they dont have a replacement bolt. Does anyone know a place in London that might have one?

ddraver

Try condor cycles, its not something that is commonly available. Maybe try scouring the webshops, otherwise e-mail or ring fisher, they re a bit slow but they ll reply eventually...

Yossie

Go to your local trade nuts and bolts man - they will be able to sort you out.

Any friendly garage/motorbike shop will point you in the correct direction.

They will generally only stock stainless though.

Alternatively, source details on the size you need then order a Ti one from someone like Sean at The Tuning Works (www.thetuningworks.co.uk) or Tasty Nuts and fit that after copperslipping it up and torquing into place.

AC20030_1

Thanks. Just before i go on my search is this the correct part...

Page 19, part number 11.6900.002.160
http://www.sram.com/sites/default/files ... _rev_a.pdf

Or.......
http://www.farnhamcycles.co.uk/Shop/p/3 ... lack-1-pc/

Yossie

That gives you the length of the bolt (M18/M25, whatever), but you also need the pitch (the distance between the threads)

Best bet is to take your old bolt (so long as its all in one piece) to the bolt man and either a) say "Can I have one of these please" and he will measure and hand over, or ask him nicely what the pitch and thread is, he will tell you and b) You call/email Sean at the Tuning Works and ask him for an M18 whatever pitch and he'll sell a lovely shiny Ti one to you.

You can get pitch/length measurement scales for a couple of Pounds, but if it's a one off I wouldn't bother.

racingcondor

Condor and Sigma are always worth a try, I'd also suggest Fudges Cycles as they have a close relationship with SRAM.

keef66

Buy or borrow a torque wrench. I'm guessing from your situation that you weren't using one??

AC20030_1

Tried Condor, Fudges, Bicycle Work Shop, few others and eventually found one at Cycle Surgery Shepherds Bush!!! Got them to fit it as well to avoid a repeat situation!! Keef, yeah i wasnt using a torque wrench, never had any problems in the past but this really didnt need much to strip it.....beware all!!! Or use a torque wrench!!

rake

dont oil the new one, it will give false torque readings.i wouldnt use a common bolt, the hardness may affect something else like the soft crank arm etc.

Yossie

Copperslip the new one - the slightest change in torque settings (if any, which is a point that has been debated to death on here) is miniscule compared to the faff of getting a seized bolt out. And it will seize in there very nicely considering where it is.

You can use any bolt you want so long as you are careful and torque it in properly.

ddraver

Good, glad it's sorted!