Shimano cable guide "large" diameter hole
 

Many years ago I converted an early-90s Specialized Hard Rock to singlespeed. I'd like to run it in geared mode again, and though I have a bottom bracket cable guide that seems to fit-- a Shimano SP-18-T-- I can't find the mounting screw.

The hole in my BB seems to be a perfect match to the larger of the two holes in the guide:

http://www.universalcycles.com/shopp...&category=1613

Any idea if the adapter typically comes with both size screws? And if not, is there an easy workaround out there?

I have another cable guide (from a different frame) that just uses a plastic post to keep itself in place, rather than a screw, but it shifts around in the (too large) mounting hole a fair amount when I test-fit it on the Hard Rock. I wonder if this will affect index shifting crispness.

Those come with a metal washer that resembles a top hat without a top. It reduces the size of the large hole to fit a typical 5mm bolt. If you don't have it, that's OK, the important thing is to have it fastened against the BB shell so it doesn't shift around.

Awesome, I think I've found a picture of the top-hat / washer thing:

http://www.moruyabicycles.com.au/con...%20sm-sp18.jpg

Yeah, that's the one :)