Front and Rear Sprocket sizes (Pointy 09) Fully Faired?

[jambo]

Originally Posted by nikon70

this is actually quite interesting, as I am getting pants mpg on the motorway at the moment, mind you I do pelt it up the m1

If I had the time and money I would swap the chain & sprok depending when I am going but that's just too much of a faf...

I might go up a few teeth on the rear and down one or two on the front when I change the chain....

good read

Up at the back, down at the front is lowering the gearing. So your fuel economy on the M1's unlikely to improve

A larger front and / or smaller rear raises gearing for lower RPM for a given road speed & gear combination.

at 15/45 as a baseline, the rear is 3x larger than the front, so 1 tooth up or down at the front is the same as a 3 tooth change at the rear.

Jambo

[aesmith]

Originally Posted by nikon70

I might go up a few teeth on the rear and down one or two on the front when I change the chain....

Have a look at this web site, you can try different combinations and see the resulting speeds at different revs ...

Gearing Commander

I don't know if the absolute figures are correct as it predicts slightly higher speeds than I actually see, but it should help see how much difference a given change would make.