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Old 08-11-05 | 01:54 PM
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Aeroplane
jack of one or two trades
 
Joined: Jun 2005
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From: Suburbia, CT

Bikes: Old-ass gearie hardtail MTB, fix-converted Centurion LeMans commuter, SS hardtail monster MTB

Originally Posted by eMwolB
Is there a chart or formula to figure out gear ratios, etc...I feel like I'm in trig...or was it calc??? - where's my abacus?
If you're not lazy, here's how it goes:

ratio = ring teeth / cog teeth

gear inches = ratio * wheel diameter = ring teeth * wheel diameter / cog teeth

gain ratio (some statistic that SB made up) = gear inches / crank length = ring teeth * wheel diameter *.5/ cog teeth / crank length

development = gear inches * pi = ring teeth* wheel diameter * pi / cog teeth

There's your formulas... FOREVER!
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