Bicycle Mechanics - How tight do you crank down on the drive side of the BB?

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.
look171
01-13-11, 04:56 PM
It is Octalink 9 speed 105. I cranked down on it a little but but the spindle feels too tight. When you spin the spindle, it feels rough. similar to a over tighten old fashion ball bearing BB.
Old Hammer Boy
01-13-11, 05:39 PM
I'll make an assumption that you installed the non-drive side cup first. That's normal procedure. As I recall, the drive side should be torqued to about 25 ft/lbs. for most cartridge If the bottom bracket isn't quite as wide as it should be, when you tighten up the drive side with the non-drive side in place, you can put a bit of a bind on the bearings. To test this out, back off the non-drive side cup to see if things loosen up. If so, you have a couple options. Put some teflon tape on the non-drive side cup and leave it backed off, or obtain an appropriate spacer. I've experienced this with cartridge BBs.
DieselDan
01-13-11, 05:52 PM
You cannot adjust the bearing preload on a cartridge bottom bracket.
Old Hammer Boy
01-13-11, 06:29 PM
But you can put a bind on the cartridge by squeezing the cartridge too much. I've seen it several times.
look171
01-13-11, 06:29 PM
You cannot adjust the bearing preload on a cartridge bottom bracket.
I was thinking the same thing. The spindle spins freely when it was out of the BB. It look and feel good, until it goes back in with the none drive side tighten, then it runs really rough. sound like I need a new BB.
Why do they make the Dura Ace lock rings different from ultagra or 105? Weight? I have a DA crank and BB but it wouldn't work with the 105 because it is a triple. I have never had a triple, I am getting older, I feel I will need it.
operator
01-13-11, 07:46 PM
But you can put a bind on the cartridge by squeezing the cartridge too much. I've seen it several times.
This is completely false.
If the BB binds (the drive side cup torque is 50-70nm), then it's a facing/chasing issue with the bb. BB cups, like the 105 that sit flush against both faces will exacerbate any facing issues - which shows up as a binding problem on proper torque. Additionally, this can also be a coaxial problem with the L and R shell threads.
Again.
Solution = chase + face BB shell.
operator
01-13-11, 07:48 PM
I was thinking the same thing. The spindle spins freely when it was out of the BB. It look and feel good, until it goes back in with the none drive side tighten, then it runs really rough. sound like I need a new BB.
Why do they make the Dura Ace lock rings different from ultagra or 105? Weight? I have a DA crank and BB but it wouldn't work with the 105 because it is a triple. I have never had a triple, I am getting older, I feel I will need it.
Dura ace or not has no bearing on whether it works with your 105 triple. It's the length that's the issue. For road 109.5 is for doubles and 118 is for triples. There are two versions of the dura ace octalink bottom bracket. The one that features an adjustable lockring on the L cup is the "cup and cone" version of the BB. The other is the same design as the ultegra/105 octalink versions, 2 piece.
Old Hammer Boy
01-13-11, 08:49 PM
This is completely false.
Okay, I guess I need to be educated and will appreciate your suggestions. I'm always open to learing something new.
Here's my experience, and thus the reason for my response: On a few bikes I've worked on, including my own, a Surley LHT, I've experienced what feels like over-tightened bearing races when the drive side is properly torqued and the non-drive side is mounted flush to the face of the BB. When I've backed off the non-drive side cup just a mm or 2, the binding goes away. So I've resolved this by putting a small spacer between the non-drive cup and the face of the BB. My conclusion was that forcing (loading) the cartridge too much from both sides could create a bind, much like over-tightening non-cartridge races. That is the basis of my recommendation. Am I wrong because not enough force can be applied to the cartridge to cause this? I'm not a professional by any means, but I've been around bike wrenching and feel like I can handle most issues and always wish to learn.
Are you saying that because of a less-than-perfect BB face, or a non-right angle face, the cartridge can experience some binding?
look171
01-13-11, 09:52 PM
This is completely false.
If the BB binds (the drive side cup torque is 50-70nm), then it's a facing/chasing issue with the bb. BB cups, like the 105 that sit flush against both faces will exacerbate any facing issues - which shows up as a binding problem on proper torque. Additionally, this can also be a coaxial problem with the L and R shell threads.
Again.
Solution = chase + face BB shell.
I am not sure if I understand. The cone threads inside the BB shell. How does facing the shell help the way the cone sits? Still, if the BB spins freely out of the shell, then once I tighten the cone only on the drive side, then it feels like its too tight. But, I can't understand why it feels like its binding somehow. I haven't chase the threads inside the BB shell. It threads in there without issues by hand. This is the same BB that came out of there.
operator
01-13-11, 10:30 PM
Okay, I guess I need to be educated and will appreciate your suggestions. I'm always open to learing something new.
Here's my experience, and thus the reason for my response: On a few bikes I've worked on, including my own, a Surley LHT, I've experienced what feels like over-tightened bearing races when the drive side is properly torqued and the non-drive side is mounted flush to the face of the BB. When I've backed off the non-drive side cup just a mm or 2, the binding goes away. So I've resolved this by putting a small spacer between the non-drive cup and the face of the BB. My conclusion was that forcing (loading) the cartridge too much from both sides could create a bind, much like over-tightening non-cartridge races. That is the basis of my recommendation. Am I wrong because not enough force can be applied to the cartridge to cause this? I'm not a professional by any means, but I've been around bike wrenching and feel like I can handle most issues and always wish to learn.
Are you saying that because of a less-than-perfect BB face, or a non-right angle face, the cartridge can experience some binding?
Yes.
Sorry to come across that blunt.
Bottom brackets that have flanged cups (e.g op's BB-5500). If you attempt to run in both cups, with faces that aren't parallel. it will put an odd sideload on the left bearing - causing it to bind when tightened down fully. When the left cup is backed off even a tiny amount, so that it does not touch the face, it will not bind.
That's how you know there's a shell issue. An added complication is that non coaxial BB shell threads can also add to the problem. Meaning you might as well chase the threads, and face it at the same time. This will get rid of the problem.
Old Hammer Boy
01-14-11, 05:41 PM
Thank you. I've had this experience while working on my Surly LHT and 3 other LHTs + one 10 year old Serotta. I suspect it can't be good for the cartridge either. Of course, I've always known that there were no adjustments that could be performed on your typical sealed cartridge BB. Backing off +/- 1/2 a turn on the non-drive side smoothed out the bearings, hence my observation, but I've already said that. Guess we'll have to look at some facing and chasing; perhaps a group discount.
Powered by vBulletin® Version 4.1.12 Copyright © 2013 vBulletin Solutions, Inc. All rights reserved.