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New BB-UN300 defective??

Old 08-05-23, 11:41 AM
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New BB-UN300 defective??

Dear All,

I've just received a new Shimano BB-UN300. As I hold the cartridge housing and turn the axle, I feel soft, regular bumping. 6-7 bumps per turn of the axle regardless of the direction I turn the axle. Is this to be expected?

Best to all,

Recovering
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Old 08-05-23, 11:45 AM
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Originally Posted by recovering
Dear All,

I've just received a new Shimano BB-UN300. As I hold the cartridge housing and turn the axle, I feel soft, regular bumping. 6-7 bumps per turn of the axle regardless of the direction I turn the axle. Is this to be expected?

Best to all,

Recovering
no.. you have a defective part.. return it.
a good BB will turn smoothly with no restriction and zero play.
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Old 08-05-23, 03:18 PM
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I suspect that your feeling dried or hardened grease. It's bumpy because the BB was stationary in storage, so lumps formed between the balls.

This is par for the course, especially for stuff that sat around a long time.

If you're worried, bolt something to the spindle and spin it a while to see if it resolves.
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