Will a double do me?
 

Just a quickie chainline question:

For a '77 Peuguot conversion (to fixed, of course) am I better off using a road double to get a decent chainline with, say, a 107 or 110 BB -- or will an old triple (which I happen have) do the job?

I know a new track crank would probably work best but I have access to used components. Hub: Harris Cyclery brand.

Any specific recommendations from those who have converted a bike like this would be greatly appreciated.

I'd rather use a double, but if you have the parts lying around, slap them on there and see if you can get it to work - I dunno about you but I love tinkering around and trying to get stuff to work when I'm not sure whether it will or not. If not, no harm done, right?

Besides, I don't really know the answer off the top of my head.

i imagine it Could be done with either but with a double it would be easier to sort any chainline issues

What BB length you need is upto you to figure out but if you are using a triple i imagine your going to need something shorter than 107, Or maybe i have no idea what i'm talking about. Set it up and measure.

Really, that's just the best advice. It's easy to give it a quick check, and there's info on Sheldon Brown's site regarding how to measure everything. Be aware that you may not have non-standard bottom bracket threading: http://cyclespeugeot.com/Threading.html. If it's not ISO, hold onto those bottom bracket cups if you find you need a different spindle length.

Three potential probs with a triple:

1. cosmetic. A crank can be a beautiful piece of metal. Unnecessary bumps and such would bother some people.

2. chainline. the two outer ring positions are likely farther outboard on a triple, and getting the chainline as in-board as possible is the name of the game in a conversion.

3. Rub on chainstay. If you bring the crank in by using a shorter spindle, you may find that the attachment points for the granny gear will hit the chainstay. Of course they can be ground off to avoid this issue.

jim

Fortunately, the BB shell is English threaded. I'm familiar with Sheldon's brilliance, having set up my other FGs according to his instructions. But today I wondered if the double was the best (and fastest) route to chainline happiness. Given everyone's helpful advice, I'll now assume it is.

Thank you.