Folks, I am seeking your advice.
Several months ago, I discovered that my Hollowtech II BB non-drive side bearing was stiff. While the problem was cured by replacing the BB with a new one, I also noticed that the bearing facing surface on the crank spindle was slightly corrded. Cleanning this up seemed to cause no problems, and the new BB was a huge improvement.
Now however, less than 6 months later, the new BB has failed in the same place. The bike has had some reasonable use in this time, but probably less than 500 miles in total.
My question is - is this within normally expected limits for BB bearing wear? Or, could the minimal corrosion (smooth to the touch, no play) on the spindle be letting in enough water to cause corrosion on the BB. In reality, I cannot imagine this last, but cannot be sure.
How tight did you do up the funny retainer ?
Is it a shimano BB? I never get more than 12 months out of a shimano hollowtech BB. I do seem to be getting a lot more life out of the Hope BB's though.
Check the Hope Tech video for fitting these BB's. It may be that you are pre loading the bearings too much and reducing their life as a result.
The corrosion on the spindle shouldn't affect the bearing life unless there is enough material missing to effectively reduce the diameter of the shaft.
Jeff, thanks for that - useful input.
Weeksy - good question. As it was several months ago, I have no idea. I guess you are suggesting that I may have put too great a side loading on the bearing? If not - why do you ask?
PS - 2009 RF Evolve XC crankset - it does up with a "normal" crank retaining bolt into the spindle end. Hence, needs to seat the crank on the spines, and tighten to the correct torque, but it shouldnt be able to overly compress the crank onto the bb? Should it? (spot the un-trained mechanic!).
[quote=dogtiredandwired ]Jeff, thanks for that - useful input.
Weeksy - good question. As it was several months ago, I have no idea. I guess you are suggesting that I may have put too great a side loading on the bearing? If not - why do you ask?
PS - 2009 RF Evolve XC crankset - it does up with a "normal" crank retaining bolt into the spindle end. Hence, needs to seat the crank on the spines, and tighten to the correct torque, but it shouldnt be able to overly compress the crank onto the bb? Should it? (spot the un-trained mechanic!).
Ah. The Raceface cranks have a number of spacers on the actual crank axle. If you've left them all on, then there's a chance you're over-loading the bearing.
Druidh, I thought of this and (while it is not in front of me I cannot check though) am surprised that what was correct with the previous bb would not have been correct with this one. Will look when I get home though.
Ta,
DTAW
DTAW - it wouldn't take much. If the bearing or seal in the Shimano BB was just slightly thicker than the original RaceFace, then you would, indeed, have to remove an axle spacer or two.
I'd try fitting it with no spacers and then see how much lateral play you have.
Druidh, good suggestion - thanks.
