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-   -   BB Cartridge under torqued but over tightened (https://www.bikeforums.net/bicycle-mechanics/19101-bb-cartridge-under-torqued-but-over-tightened.html)

sakarias 12-22-02 07:38 PM

BB Cartridge under torqued but over tightened
 
I have installed a Shimano ES-70 bottom bracket cartridge on my bike (as part of changing from Shimano 105 to XT series to move my bike's gearing down for a better range for touring).

I have done this on another bike without problems. This time I have an unexpected issue.

My problem: When torqued to about 450 in-lbs (the specification range is 435-608 in-lbs -- from Shimano's literature), the spindle has an over tightened feel, not turning smoothly and being rather stiff. When I backed the lockring off to the point where the spindle just ran smoothly, the torque was only about 200 in-lbs.

All one bike maintenance book I have says about a situation like this is to "... try again." Ok, fine. What is this supposed to mean?

Anyway, I greased the right side threads before I installed the main body of the BB. I used anti-seize compound on the lockring (since it is aluminum alloy while the frame is cro-mo and the cartridge stainless(?) steel.

I tightened the right side tight against the BB shell.

In addition to the anti-sieze on the lockring threads, I spread a layer of Phil Wood grease on the hard rubber seal on the inside of the lockring.

Initially I tightened the lockring by feel using a 12" wrench. Then I checked the spindle. When I found the spindle felt over tightened, I brought out the torque wrench.

I am guessing the BB may be defective, though brand new. That is a bit unexpected. Any thoughts? Any similar experiences?

(I have searched the Bike Mechanics Forum and not found anything similar brought up before.)

sakarias 12-22-02 09:49 PM

Answering my own question -- I think.

A slight amendment to my previous post/question: It was actually my daughter who was installing the BB with my verbal assistance.

In checking things out, looking for a reason for the problem, I found that she has really tightened the fixed side of the BB cartridge. I did not think that was an issue at first. It is what I had told her to do. But, I loosened it and snugged up using my "calibrated" hands. Then I torqued the lockring side. NOW, the spindle turns freely, with just slightly more resistance that when I try it not tightened down, and there is none of the unevenness. So, now I am guessing that then the LBS prepared the shell, they did not perfectly face the shell. With a very, very slightly less tight fixed side, the lockring can better align the cartridge.

How's this for an analysis?

pokey 12-23-02 07:52 AM

I think you may be right.Was wondering the same thing.BB facing is not usually the issue with cartridffges it use to be with ball and cone,but there could be exeptions.


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