Crank post

[Phil H]

Looking for some ideas on the best/cheapest way to resolve this one.

When we got Tom's bike, it originally had a double 53/39 chainset on - which I reckoned a bit much for a small(ish) boy. So in the shop they said they had a 2nd hand compact they could put on. It's a nice looking FSA job with a Hollowtech style BB so better that the original. That was fine for a while but recently the left crank keeps coming loose. No matter how much I tighten it, it will loosen - and it's getting worse. I'm assuming that the crank is worn where it clamps onto the spindle so no amount of tightening is ever going to really secure it. There are a bunch of options:
- Try to get a new LH crank arm
- Get another chainset that will fit the FSA BB
- Get another chainset complete with BB
- Get myself a proper double and give my Ultegra compact to Tom

At the moment I don't have any BB tools so I'd need to acquire if messing with that. Also I wonder about the wisdom of using 10 speed chainrings with an 8 speed chain - are there any wear implications there?

Of course, if anyone's got any suitable parts sitting at the back of their garage ...

[George]

hacksaw the groove wider

[Phil H]

[quote="George"]hacksaw the groove wider

[George]

give it a go clamp in the vice with a rag to protect the aluminium surface

[Paul H]

Is it an ISIS BB? What is the crank length?

[George]

no paul its the hollowtech one which uses a different bb from isis with external bearings

[Dan_K]

I've got a hollowtech BB wrench if you want to borrow.

[Phil H]

[quote="Dan_K"]I've got a hollowtech BB wrench if you want to borrow.

[Grahame]

A good slathering of threadlock might help as well. [url=http://www.loctite.co.uk/cps/rde/xchg/henkel_uke/hs.xsl/loctite-4087.htm?&countryCode=uke&BU=industrial&parentredDotUID=productfinder&redDotUID=productfinder&param1=brandRedDotUID%3D0000000389|x%3D0|subsubapplicationRedDotUID%3D|subapplicationRedDotUID%3D00000002IP|mode%3Dsmall|y%3D228|applicationRedDotUID%3D0000000276|pageIndex%3D0|action%3Dsearch|]Loctite 243 or 262[/url] ought to do it.

[Elliot M]

I believe FSA cranks are notorious for this...

[Dan_K]

[quote="Elliot M"]I believe FSA cranks are notorious for this...

[Dombo]

Might be worth looking on ebay for a used compact or even get a new one eg Sora/Tiagra from chainreaction/evans/gb in their sales and sticking your old one on ebay to part cover the cost. My old kit always ends up on there - just make sure you're honest about the condition and it'll always find happy buyers.

[Phil H]

Thanks all. I think I managed to widen the gap a bit last night and get it a bit tighter on the spindle. Will see how it goes next time Tom rides it.

An alternative option is maybe to get an MTB chainset (lose the small ring) that might give him race-legal gears. Hmm.