KR-1S.co.uk Forum

Just finished fitting an aprilia rear wheel, was going to go down the RGV vj22 route but weren't many available and when one did appear they were going for £60+ with no disc or sprocket carrier.
Anyway took a chance on the aprilia wheel for £25 with a good tyre, disc and sprocket.
I swapped the wheel bearings for ones with a 17mm bore and made a spacer tube the same as the aprilia one but with an 18mm bore.Then turned down the disc to 210mm and reduced the thickness of the flange on the top hat spacer that that holds the rear caliper by 5mm.Then made two new wheel spacers 35mm diameter x 17mm bore one 25mm long the other 9mm.These spacers keep chain alignment correct. The original caliper is fitted and is probably 1 or 2 mm off centre but because its a sliding arrangement should be able to accommodate this amount.

Have you got any pics?

thanks,
Charles

Have you had to fit it the wrong way round? I thought the rs125 had the chain on the wrong side?
Cheers
AL

Yes the 125 does run the chain on the "wrong" side and this means the wheel is reversed on the KR1S but when you consider both front and back wheels have the same spoke pattern and direction on most bikes and yet the forces are in different directions on each wheel ie braking on the front and acceleration on the rear so it should be ok to run them in either direction.

DAMO666 wrote:Yes the 125 does run the chain on the "wrong" side and this means the wheel is reversed on the KR1S but when you consider both front and back wheels have the same spoke pattern and direction on most bikes and yet the forces are in different directions on each wheel ie braking on the front and acceleration on the rear so it should be ok to run them in either direction.

I know the MZ racing boys use them the wrong way round, so shouldnt be a problem I was just wondering about the cosmetic thing really what does it look like?
Cheers
AL

I've got the zxr400 front end fitted with the 3 spoke wheel, so they don't match, but its a track bike anyway and it was a performance upgrade rather than aesthetic.It would look better with the standard KR1S front wheel though.

Just got round to taking a few pictures.

it looks "wrong" , but luckily that has no effect on laptimes

Out of interest what size width is the rear wheel?

Not sure, it does have a 150 section tyre fitted.

Done a drawing of wheel spacers for Aprilia wheel on Autocad, but photobucket doesn't like pdf format so had to take a screen shot.If anyone wants a version to print i can email.