santafritz

I have an old Ritchie Logic mountain frame that I'm making into a touring bike. Because the chain rings are largerer, I have to get a wider bottom bracket--110 to 127--so the rings dont hit the frame. Has anyone does this? What are the pros/cons for different size bottom brackets?

shortbus

This is off the top of my head and I've never been accused of having a good memory (not for the actual truth, anyways).
I think the origin of your problem is the frame came with those flash in the pan chain rings where they were slightly oval in shape (the name is on the tip of my tongue but not quite there).
Waaaaay back I had one of those and I've always liked ruining my knees with excessive chain rings. I think it was a 52 I put on it. That's with the original bottom bracket.

climbo

you will need to re-adjust the shifting and derailleurs as the chainline will be different but other than that, the only difference is that your pedals will be 8.5mm further our on each side. This may be a problem or not, it depends on you, some poeple don't like to change this but really, I ride 4 different bikes and all have different "q-factors" and I have no problems. It's just something to get used to, 8mm is not much.

jeff williams

I just went to a 122.5..(Ritchey frame too.) umm, with my mtb triple, I'd still only get 40T ring mid in there..(have only a 38T ring mounted) and that would be very close to the chaistay.

I'd think 127.5 would put you too far out and mess your chainline.

What size rear cluster? Also..how about reducing the cogset teeth instead of increasing the chainring T amounts? If it's speed your after?

Roughly a 2 front = 1 rear ratio.

Now's when I get told to quit being 'creative' to solve problems.

Can I see a pic of the Ritchey? (love 'em.)