Integrated Bottom Bracket
 

I have searched and not found the exact question/answer to my problem.

I am converting my late 90's (I think 1999) Cannondale F500 Fram to a full time commuter and would like to put a compact double on it. It will never see anything more than a tow path again and even that is rare.

I bought a Shimano FC-R600 Crank with the corresponding BB cups. Tourqued the cups, seated the driveside crank, fit the non-drive crank; everthing was going perfectly.

When I gave it a spin, I got just the slightest "ting" from the 50T on the chainstay.

I understand chainline and setup and know what I can and cant do with regard to those seettings. The question is; can I put a spacer behind the drive side cup? Is there tolerence in the BB length to accept 2.5mm? Will the shim from a Shimano XTR crank fit behind a road cup?

If I am out of luck, let me know

sound like it does indeed need the spacer(s).

don't know much about this setup except my chainset/bb wanted two spacers on the drive side & one 'other (68mm shell) - the extra spacer is there to cover the non-bb mounted front mech (seat tube clamped mech)

This is an external BB crank, right? If so, then won't the crank axle be too short for the non-drive side crank arm to fully seat?

Thats what I am not sure about. What I am trying to figure out is if there is enough extra axel length to accomodate a spacer.

I did call an ask Shimano Tech. A lot of good that did me. As soon as they heard Road crank and Mountain frame, I was told it wouldn't work.

So, does anybody think it would work? How much of the axel needs to be in the non-drive side crank?

The problem with mixing the two is that a mtb frame uses a 73mm hanger tube and a road frame uses a 68mm tube. As I recall, some Shimano cranksets include a spacer and can be fit to either, but the R600 doesn't. I wouldn't try to use the two together. 5mm is a significant fraction of the retaining bolt threads.

You could try 'facing' the tube down 5mm, but if you're already hitting a stay that would just make it worse.

What chainline are you targeting? 42mm?

Are you changing from a triple or a double?