anyone running shimano 105 cranks? what size bb for 42mm chainline?
I'm doing another cheap build for my daily commute. For those of you running Shimano 105's with 130bcd chainring, what BB size are you using get a 42mm chainline? I want to run the ring on the outside if it's possible.
What Soil Sampler said for octalink---afaik there isn't a shorter one available. If you have some old square taper 105, you can get a 107mm bb and run your ring on the outside at 43~ mm. Slamming the crank in that close can create clearance issues depending on your frame---you'll just have to try it and see. I had to file the horizontal tabs that hold the inner ring back a mm or so on my 600s. But it does work fine now.
You might just try whatever BB you already have, if it is on the cheap. My quietest bike has the worst chainline--- some square taper that just happened to be in stock when I was running it with gears (attached to a Stronglight road crank). Go figure.
On my roomates bike I set up a single speed drivetrain using 110mm Shimano Octalink BB and the chainline is just fine. I have never taken the time to measure it, but eyeballing it is close enough. 1 or 2 mm does not matter
^^ Yes twitcho, Shimano doubles + their recommended bb generally put the inner ring at close-enough-to-42, outer ring at 46ish. The trick for people like op is to find a short enough bb and sufficient clearance to get the outer ring to 42ish.