does it make a difference on how many teeth you have, what would be good for hillclimbing.

 

The # of teeth you run is called gearing. Stock is 13/40. If yo put on a 41 rear you get more torque with less top end speed. Just the opposite if you put on say a 39. SOmeone will eventually come on here and explain the ratios since I'm not good with that.

 

13/40 means 13 in the front and 40 in the rear if you want hill climbing you need more low end go up one to two teeth you will notice a difference by just adding one. I would either just leave the front one the same or change it out with one that has the same number of teeth. If you go up in the number of teeth in the front it is more top end if you go down then it is low end.

 

To know your gear ratio divide the front sprocket number of teeth into the rear sprocket number of teeth. In other words 13 divided into 40 is a 3.07 gear ratio. The higher this number the slower you go but you have more torque. The lower the number the more top speed you have but less torque. The only reason you would lower your gear ratio for hill climbing is if you are bogging the engine down. If your engine can handle it stay with the same gear ratio that way you have wheelspin.
Let's say you want to lower the gear ratio and you went with a 12 tooth on the front. 12 into 40 is a 3.33 gear ratio. If you want to change the rear sprocket and get the same gear ratio you would have to have a 13 on the front and a 44 on the rear. 13 into 44 is a 3.38 gear ratio.
Changing 1 tooth on the front sprocket makes a big change in gear ratio but a 1 tooth change on the rear sprocket is a smaller change in gear ratio. It is also always cheaper to change the front sprocket. put a 12 tooth sprocket on the front and see what it will do. You should be able to do this for about $10.00