When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

1972 Super Sport Cup Question

-

SirMike1983

Riding a '38 Autocycle Deluxe
Here's something new to me - the drive side bottom bracket cup sits somewhat loose in the frame. The non-drive side is tight and would need a hammer to knock it out, but the drive side I can just pull right out with my fingers. Has anyone had this - where you have a loose bottom bracket cup with a one-piece crank? When I first got the project, the bottom bracket turned OK; the cup was not turning in the frame. Once I loosened the set, it became apparent that the drive side cup sat somewhat loosely in the frame.

What's the verdict? Should I do a bottom bracket conversion on it to modern three-piece? Or is this something people just deal with and ride?
 
And I suppose the alternative to conversion is a thin shim of some kind to tighten the cup fit up just a bit. Maybe a piece of soda can or sheet aluminum?
 
And I suppose the alternative to conversion is a thin shim of some kind to tighten the cup fit up just a bit. Maybe a piece of soda can or sheet aluminum?

I was thinking along those lines also, but I'd use a beer can. I'm betting the bottom bracket shell was probably a tad bit over sized from the factory. See if the non drive side cup fits sloppy on the drive side and that should give you an idea of what is off, cup or bottom bracket.
 
All cups are not created equal. I have run into loose cups from time to time and being well stocked with used replacements I find some that are tight fitting. If you don't have access to some replacements I would recommend JB weld. Follow the instructions for overnight setting up.
 
Back
Top