Clydesdales/Athenas (200+ lb / 91+ kg) - Bottom bracket importance
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I enjoy MTB and road biking very much, but are an athletic 250#. I've read through this forum and the links in the pre-read section, but am unclear on bottom brackets. Seems to me that in non-shock situations, nothing takes more stress than the bb itself. It seems to me that if one thing makes sense to swap out (besides a good wheel build, which my mavic 317s seem fine), the bb is the thing to worry about. Anyone concur? I've heard good things about Chris king, any suggestions or negatives?
08-02-09, 12:20 PM
I wouldn't bother to upgrade a bottom bracket if the one you're currently using is working. I'm not an engineer, but it seems to me the bottom bracket actually takes very little stress. Even bottom brackets that use outboard bearings are well supported by the bottom bracket shell. I've used a number of different bottom brackets, from cheap sealed-cartridge units to high-end outboard bearing models and I honestly can't tell a difference between them.
If you ride in wet and/or muddy conditions and find that your bottom brackets wear out quickly, it might make sense to upgrade to a higher-end model with better seals and bearings. Otherwise, I wouldn't bother...
You didn't say which BB you were using, or how old it is.
on my roadbike it is a truvativ unit, on my MTB it is a no-name "power tools" item. It is noisy.
I figure getting up out of the saddle, standing up, etc., all of my weight is supported first and foremost by the bearings in the BB. Of course the pedals take the weight first, but the BB is a unitized part that takes all the force.
08-02-09, 01:00 PM
As long as it is installed properly the shell should relieve the bottom bracket from being subjected to unusual amounts of force. I've been told to stay away from titanium BBs because of weight but I have yet to experience any catastrophic failures on them. That being said I have gone back to cro-mo as I don't see a lot of benefit to Ti BBs.
One thought for my MTB, since more often than not it gets wet/muddy, is to use a stainless system. I'm not keen on Ti because I've seen all the weight issues... for BBs and particularly pedals.
08-02-09, 01:22 PM
Stainless is probably a good choice. I am using a cro-mo BB but my pedals are stainless for that very reason. My mountain bikes BB axle doesn't seem to much the worse for wear despite being subjected to wet, mud, snow and salt water on occasion. I always thought it would rust but it doesn't, at least not before it is time to replace. If I wasn't using a cartridge BB I suspect I would eventually encounter rust.
08-02-09, 09:56 PM
In considering my next bike there seems to be a lot of talk of the advantages of BB30. Does anyone know if it's really that much better? Would it be especially important for a clyde? Don't mean to hijack the thread, but it seems like the natural progression of the topic at hand.
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