For the past week ive been trying to work out what size bb i need for a set of stronglight 80s cranks riding with a single chainring!

If anyone has any information on this or previous experience with these cranks i would be ecstatic if they could give me some tips on what to go for!

Stronglight, huh? That makes it more complicated. I'm assuming that's an iso taper (like Campy) rather than jis (like Sugino). I have only limited experience with that.

What I've done in the past is to trial fit the crankset using any BB with the correct interface. That makes it easy to measure the chainline and to figure the spindle length that I need.

I donlt know how much help that is but it's the best that I can do.

I found a small comment on Sheldon's site about older Stronglight cranks being compatible with older TA bottom brackets (not sure if that makes your life any easier). Anyway, according to this (https://www.sheldonbrown.com/bbsize.html#ta) you need a 111.5mm BB.

Hey thanks for the replies! It says its ISO but there was something written about the possibility of using a JIS taper but going down a few mm's argh! its all too confusing haha!

I would only use a JIS spindle as a last resort. Mixing spindle tapers results in much less surface contact than the square taper interface was designed for. Perhaps if the bike is only lightly used you won't have problems but I wouldn't trust it on my every day bike.

i shall take your advice! cheers. I think i might have to just sell these on as i cant seem to work this out!