sprocket sizes

5 replies to this topic
  • WilfulLemar20

Posted March 12, 2015 - 07:55 PM


okay so i am not great when it comes to figuring out sprockets but me and my buddy have been having a debate my 450 has a 45 tooth sprocket when the stock should be 48 tooth, I believe the 45 tooth sprocket would make it go faster he says it will give it more torque

  • grayracer513

Posted March 12, 2015 - 09:32 PM


The 45 increases your potential speed.  The 48 would increase the delivered torque in each gear.


It's simple leverage, and it's the same deal with a bicycle.  The smaller the driven sprocket, the faster you can theoretically go.  The bigger the rear, the more load you can pull, climbing ability, so on. 


It's all a matter of how many revolutions of the output shaft it takes to produce one revolution of the driven wheel.  All motorcycle drive chain and sprocket sets are reduction ratios, that is that the transmission output turns faster than the wheel does.  The more the speed of the wheel is reduced, the more advantage the engine has over the wheel, so, more torque is delivered to the ground.


Just divide the rear sprocket by the front, and you have the ratio:


48/14=3.43:1 (3.43 to 1) "lower" gearing, more torque, less top speed


45/14=3.21:1  "higher" gearing, less torque and acceleration at low speed, higher top speed

  • WilfulLemar20

Posted March 13, 2015 - 06:01 AM


Thanks a ton gray racer I never heard of dividing them to get the ratio that's awesome lol
I will just leave the 45 on then wanted to try and loss some of the torque anyway

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  • grayracer513

Posted March 13, 2015 - 06:10 AM


You probably won't like the 45 if you do much trail riding at all, or maybe even all track stuff.  Low gear will be pretty tall with that setup. 

  • WilfulLemar20

Posted March 13, 2015 - 04:34 PM


I will have to try and ride the bike in the woods prob before I jump into getting a new sprocket but most likely will end up going to a 50 tooth or more maybe I want to be able to run 2nd gear though the woods but not lose all my speed bc I have the occasional road

  • howdydooty

Posted March 13, 2015 - 06:24 PM


That is awesome for this noob I have to change my sprockets and that makes more sense that what everyone else has told me.

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