Bicycle Mechanics - Bottom bracket

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View Full Version : Bottom bracket


Halfmast
06-08-09, 12:17 PM
[I have read what Sheldon has to say and am still a little confused.]

I have an old style American bottom bracket (frame's from 1981). One piece cranks. Am I doomed in my hope of getting nicer cranks/chainring? I also would really like foot retention but the pedals are like half-inch or something and nothing fits. If I could get new cranks obviously this would solve that problem, but do they make modern crank-sets that would fit my giant bottom bracket?


hernick
06-08-09, 12:46 PM
Well, there's a solution, but it's expensive. You could use an American-to-Euro bottom bracket converter (http://harriscyclery.net/itemdetails.cfm?ID=1335). Then, you could install a conventional bottom bracket, to which you could attach a new crankset, and new pedals.

This is gonna be pretty expensive unless you have the crankset and bottom bracket already.

Considering that most bikes with american bottom brackets are cheap bottom-of-the-barrel bikes, it probably isn't worth it.

You could also use step-down pedal adapters (http://harriscyclery.net/itemdetails.cfm?ID=1330), which are also quite expensive but would let you keep your existing crankset and bottom bracket.

Halfmast
06-08-09, 01:20 PM
Very helpful. The converter looks like a better bet in the long run since my chainring sucks and i'd like a new one anyway. I would just get the pedal thread step down thing, but jeeze 45 bux for two hunks of metal?


hernick
06-08-09, 01:59 PM
Yeah, two hunks of metal that have been machined by hand in America by an american. That's expensive indeed! But I figure the demand for that step down adapter is so low that nobody wants to order a couple thousand units from China...