Needing help to figure out where and what I need as far as bottom bracket sets for opc. Going in a 1970 schwinn 10 speed with diamond crank. Also have two murray montereys. Also need fork for schwinn and headsets for all three. After that should be easy, just can't seem to wrap my head around all the bearing sizes, I do get schwinn 28tpi and the murrays use standard 24tpi. Thanks for any and all help.
one piece crank advice
- Thread starter b52fizzle
- Start date
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American bottom brackets are the same size... but vintage Schwinn one piece cranks have different threading (28tpi) than most common one piece cranks do (24tpi). If you're going to use the Schwinn crank, you'll need a vintage Schwinn specific BB set.
However, a Murray crank and BB set will fit a Schwinn bottom bracket, and vice versa.
Older headtubes typically take 1" threaded headsets and forks. Some can fit the slightly larger old school 1" threaded BMX headsets and forks, too. The Sheldon Brown website has a lot of info on all this.
However, a Murray crank and BB set will fit a Schwinn bottom bracket, and vice versa.
Older headtubes typically take 1" threaded headsets and forks. Some can fit the slightly larger old school 1" threaded BMX headsets and forks, too. The Sheldon Brown website has a lot of info on all this.
^^What he said, except that you can get new 28tpi OPC BBs: http://www.niagaracycle.com/product_info.php?products_id=508936 You're probably better off if you can find an older one in decent shape and rebuilding, but that'll do in a pinch.
As for the cup/bearing sizes: do your frames not have any cups in them? I'm willing to bet that you'll need the fatter, 32.5+ mm cup headsets, rather than the standard 1" with the 27mm+/- cups. Always best to measure first, in my experience. If your bikes already have headsets or even just cups, you might be best off using what you've got to the best of your ability.
As for the cup/bearing sizes: do your frames not have any cups in them? I'm willing to bet that you'll need the fatter, 32.5+ mm cup headsets, rather than the standard 1" with the 27mm+/- cups. Always best to measure first, in my experience. If your bikes already have headsets or even just cups, you might be best off using what you've got to the best of your ability.
Some 1-pc cranks have a slightly (1/4-1/2") longer or shorter shaft. They can often be centered by adding or removing spacing washers that are sometimes found between the sprocket and sprocket-side inner bearing race. If you're trying to use a short shaft in a wide bracket, there may not be sufficient threads for the outer locking nut. :|
Cups were badly rusted pretty much just have frame to work with. Fork is trashed want to replace with an original when I find one not sure what headset looks like have to cut old one off, thanks for all the input thus far.
