Singlespeed & Fixed Gear - Chainline Challenge

building up my new fix, need some help on ordering parts. Normally, i wouldn't bother you all with asinine techy questions, seeing as how i work in not one but two bike shops, but this one has been a debated question.

bianchi pista frame, 2001. Phil wood rear track hub. for the cranks, i got some old campy victory (either that or triomphe) cranks. a double. NOW. what bottom bracket do i need to use to get a proper chainline, which will also fit the crank taper so as not to ruin them.

Current suggestions are campy track BB, or a phil BB as it's adjustable. I'm leaning toward the phil. You folks tell me what you think, with all your q factors and such.

correction: they're most likely victory cranks, as they have the self extracting bolts like c record.

I'd look up (if possible) the spindle length for Campy's track BB of that era and then get a Phil in that length. The adjustible cups are great, but you'll need a good vernier caliper if you want to be very accurate (does one of your shops have one?).

since it's difficult to find good information about what bottom bracket the victory cranksets take (one site says 109mm, one says 112mm -- might be double vs. triple if there are even both), you're going to want something with some adjustability. the phil wood campagnolo taper bottom brackets come in 102, 105, and 110.5. if like almost all doubles, the default chainline (middle between the two rings) is 43.5, then you figure that if you want to go with your chainring on the outside (so that it looks nicer) you're going to be at ~45-46mm with the standard bottom bracket. Assuming that the proper bottom bracket when used as a double is a 109mm, you're going to want something that is (also assuming that track chainline ideally is about 42.5mm) ~104mm-102mm symmetrical. since the phil wood site says that their cups are 5mm adjustable, you could go with either the 105mm or the 102mm. i'm thinking that i would go with the 105mm and just adjust it a bit to the non-drive side so that you get the tightest chainline possible without any fear of the crankset bottoming out on the spindle (as is possible, perhaps, with the 102mm). if it's supposed to take a 112mm, you should still be kosher, since the effective difference is only 1.5mm chainline and should keep within the 5mm adjustability. hope this helps.

hope this helps.

i love you shants. I hope the french bike brings only happiness to your life.

it brings me nothing but happiness.

one thing of note -- the phil hubs have a 36.75 center-shoulder distance on the track models. it seems that with most cogs, your chainline ends up being ~43-44ish as opposed to the theoretical 42.5mm. this is all the better for the 105mm as opposed to the 102mm.

Do you know which taper would suit Nuovo Gran Sport cranks? I'm also going with a Phil Wood bottom bracket on my current project.