86 87 GSXR750 or GSXR1100 wheels on a KZ1000

I'm curious if anyone here has tried to run a set of wheels from a 1986 or 1987 GSXR750 or GSXR1100 on a KZ1000 (77-80).  

I thought I recall some folks doing the swap, but searching didn't turn up much.  I found 577nitro mention it here:

kzrider.com/forum/11-projects/586776-bet...ike?start=360#781713

But it's been about a year since they have been active.

I thought maybe I recalled slayer61 doing the swap, but those were Kawasaki wheels that look a bit similar.

kzrider.com/forum/11-projects/614473-mrs...rade?start=60#838768

I'm mostly curious about how to fit the rear wheel.  I happen to have a GXSR750 rear wheel, with sprocket carrier and rotor included.  The KZ1000 rear axle is the correct size for the GSXR bearings, it right right in, I test fit the wheel GSXR  into a CALFAB swingarm I happened to have handy.  The wheel assembly fits between the arms of the swingarm, but it's a bit tight.  There isn't much room left for a bracket to hold the rear caliper.

The real issue is that the center of the wheel is substantially offset to the right side.  Comparing it to a KZ1000 LTD rear wheel I had handy, the GSXR sprocket is offset much farther away from the center of the wheel than the KZ wheel.  Just eyeballing it, It looks like I'd need to take between 1/2" and 1" off of the GSXR sprocket carrier to bring the wheel back to center, when using the stock KZ1000 sprocket and chain line.

However, the sprocket carrier is cast with relatively thin walls, and cutting that far down into the carrier would basically remove the mounting surface for the sprocket.  I don't think it's really practical to cut it down so that it has a similar offset to a stock KZ wheel.

Without making a custom swingarm, or finding one that was much wider, I guess then next option would to be make a custom sprocket carrier?  That seems possible, but not trivial.

I guess a middle ground option would be to cut the GSXR sprocket carrier down as much as possible, and then try to use an offset sprocket on the engine side?

So has anyone actually tried do put a GSXR750 or 1100 wheel on a KZ1000?  I really do think I remember folks here discussing this swap.  But maybe they hadn't actually tried it?

I need to take some pictures...


 

I a using a 600 bandit wheel in my 82 build- I have 13mm offset 530 sprocket on the front but still had to take 11.5mm off the sprocket carrier to run the wheel central

577nitro lays it out clear enough in his post. It sounds like it is gonna take a a bit of machining and fabrication on many components but fairly straight forward - assuming the GPZ1100 is reasonably close in dimensions to KZ1000. How much lighter are the GSX-R wheels than the KZ?

DOHC wrote:

I'm mostly curious about how to fit the rear wheel.  I happen to have a GXSR750 rear wheel, with sprocket carrier and rotor included.  The KZ1000 rear axle is the correct size for the GSXR bearings, it right right in, I test fit the wheel GSXR  into a CALFAB swingarm I happened to have handy.  The wheel assembly fits between the arms of the swingarm, but it's a bit tight.  There isn't much room left for a bracket to hold the rear caliper.
The real issue is that the center of the wheel is substantially offset to the right side.  Comparing it to a KZ1000 LTD rear wheel I had handy, the GSXR sprocket is offset much farther away from the center of the wheel than the KZ wheel.  Just eyeballing it, It looks like I'd need to take between 1/2" and 1" off of the GSXR sprocket carrier to bring the wheel back to center, when using the stock KZ1000 sprocket and chain line.
However, the sprocket carrier is cast with relatively thin walls, and cutting that far down into the carrier would basically remove the mounting surface for the sprocket.  I don't think it's really practical to cut it down so that it has a similar offset to a stock KZ wheel.


 

To the best of my knowledge you will definitely need an offset sprocket to allow the wheel to run central. The GSXR sprocket carrier looks very similar to the MK2 bandit item I am using (20mm axle) I have included a pic of my cut down carrier compared to a GSXR unit. The red line shows where the sprocket mounting bolts sit so still plenty of meat to secure the sprocket with 11.5mm removed. The MK2 bandit calliper hanger also has plenty of meat to allow trimming

DoctoRot wrote:

577nitro lays it out clear enough in his post. It sounds like it is gonna take a a bit of machining and fabrication on many components but fairly straight forward - assuming the GPZ1100 is reasonably close in dimensions to KZ1000. How much lighter are the GSX-R wheels than the KZ?


 

Not really.  He mentions milling the from wheel to fit, adding spacers, and the rear brake caliper.  But no details about what may have been done to the rear wheel or sprocket carrier.

As for the weight, here is what I measured for the wheel itself, with nothing but the wheel bearings installed:

78 Z1R rear 18x2.15:  6.070 kg
86 gsxr1100 rear, 18x4:  6.690 kg
Lester rear kz1000 (4 bolt disc):  6.730 kg

so it's not about the weight (clearly).  I just want a wider 18" wheel.  Even the Lester I have is the same 2.15" width as the stock wheel. 

The rear wheels from the GSXR750 is 18x3.5", and GSXR1110 is 18x4".  The fronts are also 18", at 2.5" and 2.75" width.

Wookie58 wrote:

To the best of my knowledge you will definitely need an offset sprocket to allow the wheel to run central. The GSXR sprocket carrier looks very similar to the MK2 bandit item I am using (20mm axle) I have included a pic of my cut down carrier compared to a GSXR unit. The red line shows where the sprocket mounting bolts sit so still plenty of meat to secure the sprocket with 11.5mm removed. The MK2 bandit calliper hanger also has plenty of meat to allow trimming

 

That sprocket carrier of yours does look like it's pretty much the same design.  I added a green line to your photo. 

 

That green line follows a surface that slopes out (increases in diameter as it gets closer to the base).  The casting wall thickness is roughly constant, so the inside wall follows the outside.  If one were to continue to cut that center hub surface (centering surface for the sprocket) straight down, at some point it would cut through the casting wall and the entire center bearing carrier would fall off.  It may still have enough meat for the bolts that hold on the sprocket, but I think it wouldn't be very useful without the bearing. 

I still need to try to figure out how to take some real measurements.  It's not so much about the chain location, but how much the wheel needs to move over to the left in order to be close to centered in the swingarm.  If it needs to move 10-15mm, that's probably fine.  If it needs to move 30 or 40mm, then things probably get harder.

I've never tried this swap on a Kz, but I did put 87GSXR750 wheels on my 82GS1100, which was a popular thing back in the day. CalFab swing arm, spacers and offset sprocket did the trick.