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Old 09-17-10, 01:21 PM   #1
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Stiff bottom bracket

hi all,

Put my new frame together today and the bottom bracket is quite stiff. It's a Shimano R700 crankset and I used the bottom bracket that came with it. It turns ok, but doesn't spin freely and seems like it has a little resistance to it.

Could it be that the grease is just a little dried out and will loosen with use?

Thanks
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Old 09-17-10, 01:55 PM   #2
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New Parts?
You may not notice it after a few weeks of riding on it, some seal friction likely ..
lever of the crank is long..
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Old 09-17-10, 02:01 PM   #3
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Yeah, picked it up from a trusted vendor that I do business with.
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Old 09-17-10, 02:46 PM   #4
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No way to tell remotely what you mean by "it doesn't spin freely" but some resistance is to be expected on a new BB. If it does not feel outright rough and rotates with even resistance I would not worry about it. All bearings run better when broken in with some miles, as long as they are kept adjusted.
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Old 09-17-10, 02:55 PM   #5
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Bottom brackets these days are nothing like ye old days of cups and cones where you could spin the cranks with ease. With all the seals these days, they won't spin so freely. What matters is how they spin under load, and as long as that's fine there's no worry.
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Old 09-17-10, 03:46 PM   #6
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It spins and it's even. I've just never had one that was as stiff as this one. These are the outboard cup model so there is no adjustment. I'll put some miles on it and see how it goes. Worse case is I change them with the some known good one's that I have.
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Old 09-17-10, 03:57 PM   #7
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It spins and it's even. I've just never had one that was as stiff as this one. These are the outboard cup model so there is no adjustment. I'll put some miles on it and see how it goes. Worse case is I change them with the some known good one's that I have.
Outboard, or external bearing BBs, do tend to be a bit stiffer than conventional BBs. I wouldn't worry about it at all.
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Old 09-17-10, 08:17 PM   #8
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It spins and it's even. I've just never had one that was as stiff as this one. These are the outboard cup model so there is no adjustment. I'll put some miles on it and see how it goes. Worse case is I change them with the some known good one's that I have.
When I decided to put an XT crank with external BB on my touring bike, I ran into a 'stiff crank' situation. It turned out that I had not been able to tighten the drive side cup completely, and the non-drive side would make the setup 'stiff' when tightened. I chased the drive side threads, and now the drive side cup tightens completely, and all is well!

If you can fit a thin (.o12 or so) feeler gauge between your BB cup and BB shell, you MAY not have the cup completely tight. If a feeler gauge will NOT fit in between, then it is probably seal friction at work.
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Old 09-17-10, 08:31 PM   #9
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Did you have the bottom bracket faced? If the cups are not dead parallel the axle will not spin freely.
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Old 09-17-10, 08:41 PM   #10
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Did you have the bottom bracket faced? If the cups are not dead parallel the axle will not spin freely.
They need to be parallel AND square to the BB threads.
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Old 09-17-10, 09:16 PM   #11
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And coaxial with each other. Bottom line is to get the BB chased and faced to make sure the cups are properly positioned.
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Old 09-17-10, 09:43 PM   #12
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Did you have the bottom bracket faced? If the cups are not dead parallel the axle will not spin freely.
No I sure didn't. That may be a good idea along with them chasing the threads while they are at it.
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Old 09-18-10, 06:45 PM   #13
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well, I figured out my issue. It was my stupidity... Nothing wrong with the bottom bracket or shell. The cable guide under the bottom bracket had a bolt that was too long....... Removed that, cut it, reinstalled, worked fine... Live and learn.
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Old 09-18-10, 08:16 PM   #14
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well, I figured out my issue. It was my stupidity... Nothing wrong with the bottom bracket or shell. The cable guide under the bottom bracket had a bolt that was too long....... Removed that, cut it, reinstalled, worked fine... Live and learn.

Experience is the teacher who gives the final exam first. And you passed!

Glad you figured it out!
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