Bike Forums - View Single Post - Is it normal for a crank to purr?

05-28-15 | 11:21 AM

#7

FBinNY

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Joined: Apr 2009

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From: New Rochelle, NY

Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter

Quote:

Originally Posted by rocdoc

Thanks everyone. Yes, I did test without the chain, it seems to come from the BB-crank complex alone. However, there is no vibration to the hand, everything is spinning very solidly. Just, purring...

You MIGHT be hearing the effect of excess preload, or some other issue like rubbing someplace. There's no way to diagnose via the internet, so ask a knowledgeable friend to give it a look (or listen), or check with a pro.

Odds are it's nothing, but we can't give any assurance of that.

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