20mm axle speedometer drive to fit a GS hub?

[Chuck78]

Any idea if any 20mm axle speedo drives are adaptable to GS wire some wheel hubs? & any of them close to a 110/80-18 tire size for speedo accuracy?????

[Chuck78]

I am going to run a set of Honda VTR1000F Superhawk (Firestorm outside of USA) 41mm cartridge forks that are nearly the same height as a GS1000 fork. It uses a 20mm axle. I want to pretty much always run wire spoked wheels, and a multitude of Honda CBR/VTR/VFR/CB/etc rotors are available in the same bolt pattern as our GS hubs use, so the taller VTR1000 or VFR750 94-97 forks seemed the logical answer. The VTR forks run 4 piston calipers, which are VERY CLOSE to the GS spokes, but can be clearanced, or you can run the smaller piston 01-02 gsxr1000 6 piston calipers that give more clearance, but are finicky and need the pistons cleaned every fee thousand miles. The cbr600f4i nissin & gsxr 750 tokico calipers with the same 62mm mounting dimension are the best bet, larger piston bores, more leverage than the tiny superhawk calipers, but tighter to the spokes and need angle milled slightly on the bottom inside piston bore edges. The VFR750 forks are much easier to use on wire spoke wheels, but run 1 sided 2 piston calipers that stop far better than any GS brakes but not as good as the newer 90's & 2000's 4 piston & 6 piston calipers that the Superhawk can run with little or no mods.

This is most likely going on my newly acquired ex-racer Rickman CR900 frame that has been modified with GS1100E engine mounts and extra bracing & gussetting.

I considered sticking the axle in a lathe and having it turned down to 17mm except for one end, and have a machinist make a bushing sleeve adapter with a slit in it for clamping force, or just doing that for both sides if I could find the right axle width in a 17mm.
The 20mm speedo drive seems like it would be by far the best option, custom hub spacers and bearings with the same dimensions except for 20mm i.d.


Do any of the later gs's use a 20mm front axle? The 88-91-ish GSX1100 katana may, but it looks like maybe they use a different hub interface, a plastic cross looking piece. Can anyone confirm the GS1150 etc front axle size being 17mm or 20? GSX1100 Katana 88-91?