Classic & Vintage - Bottom Bracket size on 1974 Schwinn LeTour

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oceanhai
11-10-04, 11:01 AM
I would like to convert my 1974 Schwinn LeTour to a fixed gear bike. However, I've been unable to find any specs on the bike to aid me in ordering parts. I've checked with Schwinn and the new owners (as of the mid-ninties) don't have any documentation on this bike.

What I'm currently trying to find out is what type/size bottom bracket does this bike have. I'd like to order a new crank set and single chain ring off ebay or elsewhere but I want to make sure that I don't end up with incompatible parts.

Thanks for any advice or direction you can give on converting this era of bike.

note: this also posted in Single Speed/Fixed Gear forum.

jemoryl
11-10-04, 12:00 PM
Chances are this bike was made in Japan by Panasonic, so anything you can find on mid-70's Panasonics might help.....
powers2b
11-10-04, 01:34 PM
If it has a large american bb you can purchase a conversion kit for a 3-piece crank.
If it already has a 3-piece crank it has english threads and should be compatible with modern cranksets. In either case you will need to measure the distance between the bearing cones on the bb spindle.

John E
11-10-04, 06:31 PM
BB cups are definitely 1.37x24TPI English-threaded.
They may be thin-walled or thick-walled, which will affect the distance between the bearing races on your spindle.
Proper overall spindle length is a function of the cranks as well as the spindle itself. You can use a standard road double spindle and mount your single chainring on the inside surface of the crank spider.