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Bottom bracket swap out
I've been all over the Sheldon Brown site as well as forum posts without success. I was hoping that someone here might have the specs comparison to help me determine if I can remove my current Sugino VP double crankset (and bottom bracket) and replace it with a Shimano double 6700 setup for my Univega Supra Sport frame.
Any help would be greatly appreciated. Thanks. |
Univega = English threading 68mm width + 1.37"*24tpi threading
Sugino = square taper BB 6700 = external So you'd have to swap out the BB as well (which you indicated). But make sure you get a standard English threaded crank/BB setup, not one of the BB30, BB86, or whatever the newest solution in search of a problem is. |
Originally Posted by Ex Pres
(Post 16864419)
Univega = English threading 68mm width + 1.37"*24tpi threading
Sugino = square taper BB 6700 = external So you'd have to swap out the BB as well (which you indicated). But make sure you get a standard English threaded crank/BB setup, not one of the BB30, BB86, or whatever the newest solution in search of a problem is. |
Originally Posted by Rickalodeon
(Post 16864774)
Do you think that there would be any chainline, chainring clearance or crank clearance issues? I.e. Do you know if the specs are the same for both models? Thanks.
I've put external style cranks on a couple of bikes that were from the square taper days. Admittedly a small sample of 2, but ran into zero issues - besides needing new tools. |
Originally Posted by Ex Pres
(Post 16865126)
Chainline is set by the crank/BB and the frame would not affect this - excepting some oddball [no-dish] frames and the like. You're putting a road bike crank into a road bike. Clearance should almost never be an issue with an external-type crankset, as there are not multiple spindle lengths to choose from. The spindle is part of the crank itself.
I've put external style cranks on a couple of bikes that were from the square taper days. Admittedly a small sample of 2, but ran into zero issues - besides needing new tools. Ex Pres....That was exactly the insight that I was looking for....Many thanks. |
...Just a follow up note in hopes that this might help another newbie like myself. The new crankset fit perfectly. So far, this was the easiest upgrade I've made. Had a bit of a challenge readjusting the front derailleur, but all is well.
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I was getting ready to reply, to mention that these new cranksets are all designed for 130mm rear spacing, but likely your freewheel isn't quite as wide as the intended modern cassette, so won't cause noticeable cross-chaining noise/friction.
I tend to prefer minimal "chainline" (as it is called, the distance from chainring/chainset center to seat tube center). I like to make use of the big/big cog sprocket combination with frequency, as when cresting our many rolling hills. So I usually prefer older bottom bracket designs that give me the freedom to select the chainline dimension at the chainrings. Very glad to hear your new crankset works well on your older bike though. How does it look? |
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