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.

Replace 1970s Vintage Bottom Bracket with Square Taper?

-

Martin Bike Nut

Look Ma, No Hands!
I just purchased a 1973 Continental that I'm converting to my daily-rider townie. It has, of course, the cheap, 1-piece crank and loose bearing bottom bracket. I'd like to convert this to a square taper, cartridge bottom bracket so I'd have more choices about crank arm lengths and chainring sizes.

Is this possible? Impossible? A stupid idea? :)
 
Welcome to the Cabe, there is never a stupid question here on the Cabe. There are many experts to advise you on good or bad ideas.
 
Is this possible?
Yes, adapters available. Check your BB inside, likely a beveled lip about 15mm from edge. Depending adapter may interfere inserting flush. Modification, shaving, etc may needed.
Here pic my 1972 Continental, see lip.
1627723
 
Welcome to the CABE!
Yes it is doable, and the sealed cartridge bearings and a square-taper spindle might be separate or independent improvements. A few interfaces: adapter to fit bottom bracket; adapter to fit bearings type; bearings to fit spindle diameter; spindle length?
 
Why didn't you pick up a different bike that didn't need all the modifications to fill your certain wanted requirements? How much will a BB conversion cost including all the time messing with it? Starting off with a higher end Schwinn road bike that doesn't have the one piece crank would save you some grief and probably for the same money or less.

They're only asking a 100 for this.
 
I just purchased a 1973 Continental that I'm converting to my daily-rider townie. It has, of course, the cheap, 1-piece crank and loose bearing bottom bracket. I'd like to convert this to a square taper, cartridge bottom bracket so I'd have more choices about crank arm lengths and chainring sizes.

Is this possible? Impossible? A stupid idea? :)
I'm also curious to know what was wrong with the one piece crank that it came with? Those are bulletproof cranks they used on thousands of bikes for years. Sure you could convert it, but as a daily rider, why would you want to complicate it with more parts?
 
I'm also curious to know what was wrong with the one piece crank that it came with? Those are bulletproof cranks they used on thousands of bikes for years. Sure you could convert it, but as a daily rider, why would you want to complicate it with more parts?
Good question; good point.

After decades of cycling, my knees are pretty "finicky". However, I find that if I can dial in crank length and chainring size - perhaps even a BioPace ring! - I can cruise around on a heavy town bike all day, pain free. Plus I'm lazy; I'd rather swap out a cartridge BB every few years rather than maintain the original BB.
 
Can I simply replace the 1-piece crank with a vintage spindle - like a Le Tour or Sports Tourer? (And use all the existing bearings, cups and races?)
 
Back
Top