I was doing some digging in to bottom brackets this weekend. I am trying to get a quad chain ring adapter to work.

What I have now is a 118mm square shaft bottom bracket. On the drive side I have 5mm of spacers so the crank is shifted over to the right (drive side) 5mm from stock. I still don't have enough room on the frame side for the derailleur to move in far enough to drop the chain on the 4th ring. I think I need another 4mm. I measured it just now and I think 3mm may get it, but it would be awfully tight.

This weekend I found some other bottom bracket sizes. Most of them top out at 127mm.

So here is where I am. If I take off the 5mm worth of bottom bracket spacers and put a 127mm bottom bracket on (9mm wider than what is on there now) that leaves me with 4.5mm, if it is centered, on each side that I am wider than stock - a bit narrower on the drive side than I am sitting now with the 5mm worth of spacers. If I add back in the spacers (all of them) I can get up to 4.5mm past where I am now - 5mm spacers on top of the extra 4.5mm space that the wider bottom bracket would give me. I am still shifting the whole crank over to the drive side 5mm past center, though = less thread engagement and off-center pedaling.

Thoughts? Are there any wider bottom brackets than 127mm that may be out there that I have not come across? If I could get up over 130mm (like a 133-134mm?) that may be a lot better for me.