Gearing for two wheels

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Old Jun 2, 2016 | 03:06 AM
  #1  
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Default Gearing for two wheels

I just recently acquired a second rear wheel to use for on road. I was very happy with stock 14/42 for road, and like 13/42 off road, but wouldn't mind going slightly lower.

My question is; is it possible to get the equivalent of these ratios from the rear sprockets only and use the same chain? Or will I have to switch back and forth? Idea's?
 
Old Jun 2, 2016 | 04:42 AM
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Try this app-you should be able to get the answers you need. Gearing Commander: Motorcycle Speed, RPM, Chain & Sprockets Calculator
 
Old Jun 2, 2016 | 11:30 AM
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My street setup is 14/43 and dirt is 14/45. I think the dirt is perfect for my riding style
 
Old Jun 2, 2016 | 11:40 AM
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All you have to do is divide the rear sprocket tooth count by the front sprocket tooth count to find the ratio for the 13/42, then multiply it by the front tooth count you want, in this case 14 to find the closest sprocket tooth count. Round by rule of 1/2 or decide if you want to have a shade higher or shade lower gearing when picking.

42/13=3.23 (rounded for print, not rounded in next calculation for increased accuracy... like it makes some huge difference... just did it, that's all)

3.23*14=45.23 Use the 14/45.

So there's the "math" to know what to do.

You could consider going to a 15T countershaft sprocket if you are near enough to buying a new rear sprocket. Bigger wears better, less chain wrap and load distributed over more teeth.
 

Last edited by klx678; Jun 2, 2016 at 11:44 AM.
Old Jun 2, 2016 | 01:38 PM
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Originally Posted by Tacoma660
My street setup is 14/43 and dirt is 14/45. I think the dirt is perfect for my riding style
That's not much of a change, only .4%.


if you went with a 13 front the change would be 7.1%.
 

Last edited by cmott426; Jun 2, 2016 at 06:21 PM.
Old Jun 2, 2016 | 01:40 PM
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So now with a 42/45 rear combo, that is 3 teeth difference.
Since the chain only sits on 1/2 the sprocket, the total rear wheel difference would be 1.5 teeth.
Look at your rear wheel chain adj, can you move it forward 13/16" (1.5x5/8"pitch)?
 
Old Jun 2, 2016 | 02:45 PM
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Old Jun 3, 2016 | 12:23 AM
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Originally Posted by durielk
So now with a 42/45 rear combo, that is 3 teeth difference.
Since the chain only sits on 1/2 the sprocket, the total rear wheel difference would be 1.5 teeth.
Look at your rear wheel chain adj, can you move it forward 13/16" (1.5x5/8"pitch)?
The 07's have a snail type adjuster. But the 14 tooth sat about the 4 mark. Think there is 8 numbers.
Thanks for the math, that will help. But I also don't know what will fit the rear before I have to edit the chain guide. I would like the lowest gearing possible to use the same chain and front sprocket for both.
 
Old Jun 3, 2016 | 01:39 AM
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Don't forget to take the tire sizes into account, street rubber being smaller.
 
Old Jun 3, 2016 | 12:55 PM
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Originally Posted by Matt88-8
I just recently acquired a second rear wheel to use for on road. I was very happy with stock 14/42 for road, and like 13/42 off road, but wouldn't mind going slightly lower.

My question is; is it possible to get the equivalent of these ratios from the rear sprockets only and use the same chain? Or will I have to switch back and forth? Idea's?
I run a 47 rear sprocket with either a 13(extreme offroad), 14(good dual sport ratio), or 15 front(good on the highway) all on the same chain.
 



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