www.zxrworld.co.uk

Hi, any ideas what sprokets I should get for my bike? I want to bring the revs down a bit on the open road, I have a lot of motorways and dual carageways around my way.

cheers

well, I think you are changing them the wrong way, particularly for a 400 with not much midrange!

but anyway...

Standard is 15 front 45 rear, which gives about 7000rpm at 70mph, 10000rpm at 100mph (in top)

16T Front, 45T Rear would give about 6500rpm at 70mph, 9400rpm at 100mph

17T Front, 45T Rear would give about 6200rpm at 70mph, 8800rpm at 100mph

by which point you have gained a bike which doesn't really accelerate, and you will get beaten away from traffic lights by kids on 50cc peds. and the rpm at legal speeds won't be that much lower.

as you might guess, I wouldn't recommend this, but each to their own.

raising the gearing a touch doesnt really hurt the midrange as much as you'd think, as there isnt any to start with

I ran 15/44 and 15/43 quite happily on a zxr4 when i was despatching on one a number of years back (yes, it hurt) and was doing lots of motorway runs.

15/43 being responsible for my 143mph ticket on the M40 .. lol, wasnt even near the redline

currently running 14/45 as the bikes now more about fun than practicality.

there's a gearing calculator on this forum somewhere now where did i put it?