This is being over complicated. You are trying to equip a road double, with way too high of an inner ring, on a bike with 60mm tire clearances. You will need a crazy wide bb to do so. 125 isn't very long, old mountain bikes with high profile cranks used them (early 80s mb-1s among them).
The solution to bottom bracket issues is to, a) search for an answer b) try out combinations. A bike shop, in which you pay for hourly rates of labor, will have a variety of these bb lengths to try in order to find the correct length for the application. If you are doing your own work, in order to save money, don't expect that the answer will be there or that paid craftspeople will be able to help you without you taking your bike into a shop and allowing them to swap combinations (and hopefully, paying for that work). This is part of the craft of the mechanic work you elected to avoid by doing it yourself. DIY is often more expensive, when starting out. In architecture, we charge to answer requests for information from the contractor, because it takes a lot of time (imagine answering the phone on the thousands of custom setups that go out the door of shops like riv, that's a lot of hours). I wonder what an RFI system would mean for shops, but I digress. So, since your custom build means a) didn't work, you've finally arrived at b) which was the place to probably start in the first place as all hand made frames are slightly different. You will likely find that 36x48 works ok with a 125mm bb, but that your chainline is pretty bad. This is why wide range doubles, not road doubles, are what riv recommends and what the bikes are designed around. Instead of returning those bottom brackets, keep them for the next time you or your friends need to try out combinations. Super cheap bb's make the world go round, and are used on all of my bicycles, since this is a constant question for people who tweak their setups. Next time, if you don't know, just go with a crank that is recommended or prepare yourself for similar headaches. Not trying to run on about this, but at a certain point the answers are only to be found in practice. Custom parts on custom builds = custom headaches. Put on the 127.5 and ride your bike, it's working and you're on your way. When you wear out those rings, drop down your sizing and put on a smaller bb, or get a low profile triple if the 46 is important, or get a 30 if the 46 is important, or or or ad infinitum. e -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/d/optout.
