GS arm/Rear wheel fitment questions

Hopefully someone here can help with my questions.
I have installed the GS1100 swingarm on my Z1 frame. I have attempted to mount several different rear wheels from assorted ZX6s. On all of them the sprocket bolts rub the left inside of the arm which will not allow me to center the wheel on the arm. The ZX6 wheel size is 17x4.50.
Does anyone know if there is such a thing as a 17x4.0 rear wheel? It needs to be a three-spoke design so that it will somewhat match my front wheel.
Now I also have a GPZ rear wheel that is a 17x3.0 size. It allows much more clearance, but hell my front tire (ZX11C) is almost that wide!
I really don't want to go with the GPZ wheels because I like the look of the 3-spoke wheels MUCH better. And besides, the GPZ wheels weigh a hell of a lot more than the more modern wheels.
All thoughts and suggestions are much appreciated.
Jim

You will need to have the sprocket carrier machined down to move the sprocket inboard, and an offset front sprocket.
I again refer to Lorcan's site: 750turbo.com/zx6_rear.htm
This will give you an idea what is required, but none of the actual measurements will apply to the GS swingarm/ZX6 wheel combo.

Just a thougt but should´t you align the chain line, not the wheel in center of the swingarm? I got a GSX 1100 -arm and ZX9-R rim in my ´83 ELR and if I´d center the wheel into the arm the chain line would be way off. I believe the chain-line is much more important.

I used an off-set sprocket to move the chain-line as much left as possible to match the new wider rim and to align the chain-line as close as possible but I know that the wheel-line is a bit off. If you change from a 3" rim to a 4,5" the rear sprocket will move to the left and if you then align the rim with the arm your chain-line is way off and can cause some serious problems.

Fossil: It might be possible to machine the rim to get the sprocket inwards but then the chain has no clearance to the wheel. I got about 3mm clearance to the wheel.

Post edited by: Z1109R Fin, at: 2007/01/08 08:30

Z1109R, that would be helpful IF my engine was in the frame. I'm just trying to get all the chassis and electrical in order before I completely reassemble and install the engine.
I'll get it figured out.
Thanks,
Jim

you need the wheel centered so the front and rear tires are travelling in line. if your rear wheel is off to one side, you can throw handling out the window. get the wheels lined up and then figure out the best way to get the sprockets to line up. offset front sprockets, machined hubs or a combo.
Scott

77KZ650 wrote:

you need the wheel centered so the front and rear tires are travelling in line. if your rear wheel is off to one side, you can throw handling out the window. get the wheels lined up and then figure out the best way to get the sprockets to line up. offset front sprockets, machined hubs or a combo.
Scott

Absolutely right 77KZ650, but making mods is all about compromises. Getting wheel-line and chain-line absolutely in-line can be a bit difficult. What I meant was that you should start from the chain-line and then make the wheel-line as good as possible. Slight diff in wheel alignment is not so bad as a poor chain alignment. When you adjust the drive-chain how accurately can you tighten the rear axle? 1-2mm diff in axle position allready makes a diff in wheel alignment.

Don´t get me wrong, I´m not an expert in frame geometry att all. I´ve only´built one ELR and I think it came out pretty good and I just tried to tell my point of view based on what I did with my bike.