Totally different sprocket sizes – bigger or smaller – what’s the affect on efficiency?
Ultimate drive ratio.
Divide the rear sprocket tooth rely by the entrance tooth rely and you’ve got the ultimate drive ratio. For instance: 35 / 15 = 2.33:1
If you wish to change your gearing, you may calculate the affect of the change earlier than you buy the brand new sprockets.
For instance: your bike cruises at 60 mph / 4,000 rpm and has a last drive ratio of two.33:1 – if you would like extra acceleration, altering a 35 tooth sprocket for a 37 tooth sprocket and leaving 15 tooth on the entrance adjustments the ratio to 2.47:1 (37 / 15 = 2.47:1). Divide your cruising RPM by 2.33 and multiply by 2.47. Utilizing the instance from above, 4,000 rpm turns into 4,240 rpm at 60 mph. You’ll get extra acceleration, however will sacrifice
Altering sprocket diameter can current issues – sprocket clearance on the entrance limits how huge you may go, and also you wish to keep away from going too small because the tight flip wears the chain prematurely. Moreover, you may run into issues with the chain slapping the swingarm when you go too small on entrance and/or rear. That is one thing you can not all the time see when the bike is static, the mix of swing arm motion over the bumps, and acceleration or deceleration trigger the chain to tag the highest OR backside of the swingarm.
Altering sprocket sizes might impact chain size. As roughly 1/2 of every sprocket has chain touching it, every tooth added to inventory sizes would require roughly 1/2 hyperlink of further chain. Growing complete tooth by one or two tooth can normally be accommodated by shifting the rear axle ahead barely and maintaining the inventory chain size – however when you begin altering sprocket sizes multiple or two tooth, you have to to extend chain size. Going up 4 tooth would require a sequence 2 hyperlinks longer.