Gix11

How to "recalculate speedo readings with non-standard sporckets" Submitted by Exben (Ben Shaw - Extreme Creations)

Principal You want to add a bigger sprocket to the back wheel to get better acceleration but you have no idea how your speedo will be effected by the change. Solution It works on a percentage. For example, if you have a 52 tooth rear sprocket and a 17 tooth front sprocket just divide 52 by 17 & you get 3.0588235, that means the front sprocket turns 3.0588235 times per every 1 revolution of the back wheel. If you were to change the rear sprocket to 58 teeth then do the same with 58 & 17 & you get 3.4117647. So, if you divide 100 ( being 100% ) by 3.0588235 then multiply the answer by 3.4117647 you get 111.53846, that is 111.5% or 11.5 % lower than 17:52 gearing. That means at 100km/h your speedo should be reading 111.5 km/h and at 60km/h your speedo will be reading 66.9 km/h. To calculate how far out your speedo will be, add 11.5% to the speed you want to know. Calculation Rear Sprocket teeth amount DIVIDED BY front sprocket teeth amount = X New Rear Sprocket teeth amount DIVIDED BY front sprocket teeth amount = Y 100 DIVIDED BY X TIMES Y EQUALS Percent difference on your speedo.