18" wheel options for GS1000

[triffecpa]

Just recently bought a '78 GS1000 set up as a vintage racer. Unfortunately it comes with the standard 19" front, 17" rear wheels (standard X spoke Suzuki cast wheels). The problem here is that most bias ply race tires are 18" front and back. Future plans for the bike are CBR600F2 wheels (I already have a couple of sets) so that I can run late model radials, but I'm interested in a short term solution of running 18" wheels. I'm not interested in spending the cash to build a set of spoked, aluminum rim wheels as the long term plan is for the F2 wheels. Anyway, did Suzuki make a X spoke mag that was 18" for either the front or the rear? I did see a GS425 front wheel on Ebay, but it was only 1.6" wide, and that's way too narrow. I know that the mid-late 80's GSXR's had 18" wheels (at least on the back), but I'm not sure of compatibility with the existing GS wheels and rotors. Anyone ever run across this problem?

[HiSPL]

The 80-81 GS750E has an 18" rear. I don't know of any bikes that had an 18 on the front though. A pair of Lester mags could fix you right up though....

[SqDancerLynn1]

I have a stock 81 750 18" rear wheel if you need one, your existing brakes & everthing will fit

[humhead]

77-79 GS 750e also used 18" rear wheels. The early GSXR models used 18" front & rear wheels. Not sure about rotor mounting bolt pattern.

[triffecpa]

Thanks for the info guys. SqDancerLynn1 I sent you a PM asking for a price on your wheel and a question about the rim width. humhead I was able to find a couple of early GSXR rims on Ebay, but the rotors have a different bolt pattern than the GS ones. I'll probably work on swapping the F2 wheels that I've already got before I'd go to the time, expense and trouble of tracking down a set of early GSXR wheels (which appear to be somewhat dear) to install.

[Don Lobacz]

You will find that the 18" wheel is very narrow, so you will be taking a step backward even with the best rubber. The 17" rear rim brought a noticeable increase in tire width to the GS, and there are some very nice tires that will work very well on your rims. The Metzlers come to mind first: I had a pair and found them to be wonderful for handling, especially at high speed. I now actually have the Lester rims on my bike, but the rear is a 16". I have a 140 tire on it and it just fits in the swingarm. If you go with the F2 or GSXR wheel you will need to change the swingarm too. Your target horsepower may be the best indicator of how big a rear tire you need.

[triffecpa]

thanks Don Lobacz. The bike already has an aluminum GS1100 swing arm. Not sure as the the tire width capabilities though until I get the bike home. What model of Metzlers were you using on the 17" rim? I understand from reviews of the Avon AM22/AM23 race tires, that you can safely run a 130 rear tire on a 2.15" wide rim (which is how wide the 18" Suzuki rim is I believe). I've also got a 3"x18" Honda Interceptor rear wheel, which should hold a 150 Avon. Not sure though as to axle sizes etc. If it runs the same size axle as the Suzuki, then it should just be some spacer issues to get it hooked up. Anyway, I'll keep everyone apprised of progress. Thanks Tracy

[robinjo]

GS1100 swing arm will fit a 180 wide tire, at least mine does.

[massakins]

Don't forget that the 1980 GS1000S (cafe racer model with the little quarter fairing) came with an 18" rear mag. Heavy as the others and not sure of the width. Other year S models probably had one also.