Will ZZR600 Front wheel fit in KR1S Forks ?

[Mohawk]

Hi Guys,

I'm new here because I'm trying to graft a KR1S front end onto a ZZR250 !
I know wrong bike, but that's another story.

Anyway I just bought a set of good condition KR1S forks & calipers, plus what I thought were KR1S wheels, but turns out they are KR1 wheels, so pretty much useless to me.

I've already found out via the search engine that the KR1 wheels won't fit in the 1S forks, as the calipers will hit the wheel, so I need to find an alternative front wheel. The ZZR600 appears to use the same forks as the KR1S but I don't know if they are mounted at the same width.

Whilst on the subject does anyone know if a ZZR600 top yoke will fit with the KR1S bottom yoke ?

Thanks

Chris W.

[Bikemike]

I think you are out of luck here.
My neighbour has a zzr600 so out of curiosity I measured up the front wheel.
Unfortunately the front discs are spaced a fair bit wider than on a Kr-1s.
Sorry to be the bearer of bad news,
Mike

P.s. On the positive side the zzr600 wheel ain't too pretty anyway.

[mgtkr1]

good news here. all is not lost re the kr1 wheel into kr1s forks. you will need kr1s spacers (i think, doing the same my self on a ypvs based race bike??) spindle, discs and bearings same id as kr1 rear but with od same as kr1. not sure if kr1/kr1s have same id. the above is the way ive done it. i found that calipers JUST clear the spokes but with flex under race/track conditions to account for will remove a bit of material from both the calipers (inside face) and the spokes. too much may afffect strength dangerously but only a fraction is needed for safe clearance. .5 mm everywere should suffice. that gives 1mm each side. or poss 1mm off the calipers (need to measure the wall thickness first) and .5mm off the spokes. i think the wheels wall thickness are pretty substantial but saying that they are pretty light. someone else has done this on here to the spokes. in the offending area theres writting cast onto the wheel about .5mm high so removing that gives you .5mm headstart without affecting the structure of the wheel in anyway. you will also need to a. machine a spacer which sits between the bearings in the wheel same length as std or b. use std kr1s sleeve. a cut to size rear wheel one can be used btw.

[Mohawk]

Thanks Guys, All very helpful info. The reason I considered the ZZR600 front wheel is because its the same style as the zzr250 wheel, thus leaving me a perfect 17" rear wheel match !

MGTKR1 in the KR1 front wheel, is there a bearing shoulder on the left (speedo drive) side ? There is no apparent left bearing in the wheel, the right one has a bearing & a shoulder for it to install against. Looking through the wheel from the other side does not show any damage, so I guess it has not been over pressed & the edge is smooth.

I'll take a picture & post it for your assessment, if anyone know the length of the bearing spacer that fits over the wheel spindle, but between the bearing that would be really helpful. I'm hoping the speedo drive from the ZZR will fit as they are from the same design era.

Thanks

Chris W.

[Mohawk]

Good news indeed mgtkr1. I got the calipers I'd ordered yesterday & mocked up the KR1 wheel with some old bearing I had & discovered that it will fit with a minimal 1-2mm clearance on the spokes. I suspect this is due to the larger 300mm disks from the KR1S, I believe the original KR1 had 280mm discs.

Whilst looking at the setup, I found a better way for you to make clearance without shaving the spokes as you intended. There is approx 1mm of rise in the calipers mounting points where they join to the slider, have this milled down & that will mount the calipers 1mm further away from the spokes. This will still leave the discs within the working range of the pads. If new pads cause drag on the inner side, then space the discs off the wheel 1mm to match the new caliper position !

Happy building

Mohawk.