I’m trying to fit a chain device to a 68mm bb shell, however the only way I can get it to clear to cranks is to space out the rh cup by about 5mm, this leaves approx 7-8mm of thread in the frame on the rh cup and leaves the axle that goes into the lh crank about 10mm short of the end.

I suspect this i probably not a great idea, does anybody know how much you can get away with?
Cheers,
Gareth

Makes more sense to cut the granny tabs off. Apart from not being able to preload the bearings and (probably) only clamping one pinch bolt on the LH arm, your chainline would surely be way out. The pinch bolt issue could be a serious saftey issue.

What guide are you trying to fit?

Oooooh, that’ll end in tears!

How much do you like the cranks? Tried grinding the granny ring mounts off? You can still use a ring in the middle position plus bashring but you may be able to get the cranks closer to the chain device.

You should have 3 spacers, 2 on one side 1 on the other, use that to get the chainline correct. Then swap one drive/right hand side spacer for the chain device.

Each spacer is 2.5mm.

So 5mm is fine, unless your going 5mm plus the thickness of the guide.

Maybe your best bet is to try a different guide. Try something like the MRP X1 and a blackspire stinger used together if all else fails?

I wouldnt run more than 2 spacers and the guide though, as you wont be able to fir the preload cap into the threads for a start.

Gareth, doesn’t sound like a very good idea to me at all.

On an unrelated note, have you got the message about the Magura and Marzocchi bits? We’ve left a couple of phone messages but think we might have the wrong number for you.

Hi guys, thought this would well be the case. Time to admit defeat and try another chain device. I was trying a gamut double ISCG on the older style XT HT II cranks or old style saint with an adaptor for fitting it to a bottom bracket, was getting potentially getting into serious bodging territory!

Cheers Matt, will give you a bell in the next few days or I have an email in my profile