What size BB for correct chainline?
 

I have an old frame I'm converting to SS/Fixie. I have a rear wheel with the White ENO to help deal with my vertical dropouts. Sheldon says it has a 47.5mm chainline. I'm looking to buy a new ISO square taper BB and crankset (probably eBay for both) to go with. My BB shell is 68mm, and I see there are tons of Shimano cartridge BB's on the 'Bay for (I think) reasonable $$. There are different axle lengths, though, and I want to get one that will work.

Or do I have to pick the crankset first? In which case, looking for recommendations there as well. Not looking for fancy colors, or awesome finish. Just plain silver and competent (i.e. round).

Thanks for pointers!

Shimano doesn't use ISO, so if you are looking @ shimano bottom brackets, you should look at a crankset that uses a JIS tapered bottom bracket. You're pretty much limited to a small group of cranks with ISO anyways, a good chunk of them are pricey.

If its on the cheap a 110mm axle cheap shimano cartridge will get you in the ballpark of the correct chainline, but it is dependent on the crankset you use

Sorry; guess I didn't mean ISO, at least not in terms of taper. I was attempting to refer to the "bottom bracket to frame" interface, which on Sheldon's site is labelled ISO. Sorry for the confusion. How about this Sugino XD + Tange 110 mm?

http://bikeforums.net/attachment.php...hmentid=215562
I use this Sugino BB with an 1/8th inch "track" crank. 120mm rear hub. Chain lines up nice. Replacing it today, lasted about 2000 miles before it started knocking.

The more I read, the more confused I get. For instance, on the White Industries FAQ it says chainline is 47.5 on the freewheel side but 43 on the fixed side. Should I be aiming for a 45 mm chainline then so that both are similarly off the ideal? What exactly would a 110mm BB yield for chainline? And how does one calculate it, other than by asking here? The Sugino site shows 45mm on the XD2 when used with 110 mm BB, and when configured as a double. Isn't the chainline on a double measured between the two chainrings? How does this help me when calculating for a single? Also, that's the XD2. I wasn't able to find the XD on their site.

Phew! Thanks again for any help...

I'd get the Sugino crankset and bottom bracket and call it a day. Or you could get a Shimano square taper bb at 105mm and the Sugino crank. Or get a 109mm. Amazingly, it won't make much difference at all, especially if you use a standard road chain.

What's the distance from the rear hub to the bottom bracket? 350-400mm? and you might be off perfect chainline by 5mm? Not worth worrying about.

I've been up and down Sheldon's page on chainline. But of course, always pick up something new on a re-read. And I get that everything will probably work OK, it's just that it makes sense to me to try to target the "correct" chainline. Ordered the Sugino and a 107mm BB. Fingers crossed...

Since u bought the eno hub I understand why your doing this bass-akwards. I owned a set that I gave to my father on a SS I built built for him if this helps I ran it on the FRee wheel side mated to a campagnolo 10sp road crankset with a miche track ring in the outboard position on a chorus 102mm BB ... Dead on.