Crank measurement Q
05-19-08, 07:45 PM
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Crank measurement Q
When you are looking at cranks and it says 110 BCD, is that the measurement beetween any 2 bolts holes for the chain ring?
05-19-08, 07:47 PM
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https://www.sheldonbrown.com/gloss_bo-z.html
"On a crank set, the diameter of the circle formed by the stack bolts."
"On a crank set, the diameter of the circle formed by the stack bolts."
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05-19-08, 07:57 PM
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^^^That doesn't mean a whole lot to me? On a 5 bolt crank, what are you supposed to do, guess what the actual diameter would be? Since there are not an even # of bolts?
05-19-08, 08:02 PM
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I guess I do not understand the question...
Try this...
https://www.sjscycles.co.uk/article-B...t-BCDChart.htm
Try this...
https://www.sjscycles.co.uk/article-B...t-BCDChart.htm
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Last edited by Hammertoe; 05-19-08 at 08:06 PM.
05-19-08, 08:19 PM
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^^^That helped, you don't actually measure from a bolt to a bolt. You have to imagine a circle that connects the chain ring bolts, then measure it.
05-19-08, 08:27 PM
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If your crank has a 110mm BCD, the distance between any two adjacent chainring bolts will be 64.7mm
If it's 130mm BCD, the distance will be 76.4mm
