mailmixer

So I have a Puegoet U09 conversion, and want to get a new crank set. its a square taper bb. Can i just get a new standard like eigthinch crankset and put them on once i get my existing cranks off?

MasterJoda

The eighthinch crankset is gonna have a recommended spindle size and my guess is that the spindle in the BB of your Peugeot is bigger. Also, you might be dealing with french threading, so instead of buying a new BB you should look for the correct spindle length. Use the existing BB cups with whatever new spindle you find. Also, i read somewhere that some spindles don't work with french cups. I'm kinda drunk right now. I know this question has been answered before, just search for it.

striknein

Unless you're lucky, the spindle on the bike will be either too long (increased q-factor) or too short (chainring clearance issues) for the crank you select. It's important that the spindle length match, or at least come close, to the crank manufacturer's recommendations.

The problem is, the Peugeot UO-9 can have either Swiss or BSA bottom bracket cups depending on the year manufactured, where it was built, and what market it was built for. Easiest way to determine threading is by measuring the thread on the fixed cup. Second easiest is by trying to install a BSA fixed cup. If it threads in but it's loose, you've got a Swiss bottom bracket. Your options at that point are to find a JIS spindle made for Italian bottom brackets (difficult), purchase a new Swiss bottom bracket (near impossible), or buy a threadless bottom bracket from Velo-Orange($) or Phil Wood($$$$).

I have a 1982 UO-9, made in France for the American market. It has a Swiss fixed cup. I'd also like to point out that it uses a French headset for the French sized fork. It's also got a 24mm ID seat tube, and the only modern replacement I could find was through https://www.yellowjersey.org for 70 bucks. I've had to replace nearly everything due to wear, and while I enjoy the bike a great deal, it's getting quite expensive to rebuild. You might want to consider purchasing something a little less... funky for a conversion.

mailmixer

ok, thanks. I know it is french threaded on the bb, but I am very concerned about frame clearence. And I would just buy a new bike, but the reason I have this one (my dads old bike) Is cause I lacked the money. Hopefully getting a job soon though So i can just buy a not french bike XD

ho_kazzen

I have the same crank conversion situation too. The frame is a 86' Fuji Absolute with its stock crank/double chainring. I currently use the inner-chainring because it gives a straight chainline to my cog. BB is square taper. I was just about to purchase a crank off a friend and just install it on my bike with the stock BB but I had second thoughts about it. Is it possible?

my bad about the thread jack LOL

striknein

You're certain it's a French bottom bracket? Have you removed the fixed cup already? What year was the bike made?