18" rear wheel?

[vilguy]

Anyone know if its possible to squeeze an 18" on the back?

i just got 2 back hubs that im going to get powdercoated black and i know a guy who has offered to build the 18" rim on them. But im just wondering if its going to work! I want to be able to get some decent offroad rubber on it.

 

[Paul Young]

It's not clear which model GS you're talking about, but I've had an 18" 3-spoke alloy fitted to the back of my 1150 in the past. It used a 160/60-18 tyre & came from a K1 but the K1100 & R1100R/RS/RT all used the same 18" rear wheel size/design.

 

[vilguy]

ah sorry mines also for an 1150.

Want to make it more capable offroad and some proper tyres would go along way. Just need to ensure that the knobbles wont foul on the swingarm.

 

[Paul Young]

Well I know that you can fit up to a 190 sports tyre without it fouling the swingarm, so you shouldn't have any worries up to a 150 or 160 knobbly. There are rear wheel spacers available from Motorworks, which BWM use on some combinations of swingarm/wheel. They're about 2-3mm thick & you put them between the wheel & the FD, then tighten up the wheel bolts as normal.

 

[vilguy]

oh ok.. ill have too look into them and see if that would put the centre of the wheel out of line. Cheers buddy

 

[Paul Young]

Wheel alignment won't be an issue to within a few mm, so not something to worry about unduly. Factory tolerances on this are quite surprising & what, with torque reaction & the other quirks around these bikes' design, you'll never notice it. Some Boxercup race bikes used the spacer in order to get the 5.5" rear wheel to fit, & they didn't seem to suffer for it.

 

[Paji]

Anyone know if its possible to squeeze an 18" on the back?

i just got 2 back hubs that im going to get powdercoated black and i know a guy who has offered to build the 18" rim on them. But im just wondering if its going to work! I want to be able to get some decent offroad rubber on it.

I changed the front wheels to 21" in both my GSs (1100GS and 1150GSA) and I also try to change my rear wheels to 18" and I faced to the very seriouse problem.

Withou some dramatic changes is poïssible to make this change in 1100GS. The destination between pneu and the the rear monoblock is cca 8-10 mm in this case (not work for all tips of offroad tyres !!!)

But seriouse problem linked to 1150GS. The extension of the rear "kardan" part has to be done. It is possible to buy the special kit for it (some NL company did it I remember). Other problems is more force to the rear monofork having negative impact the the relability and service live.

I finaly resignated to do these changes in my bikes from these reasons.

 

[vilguy]

ah i have seen something similar from hpn, doing an extended swingarm.

Hmmm alot of work then... and more importantly alot of cost!

Maybe i will just start with 21" front and go from there

anyone need a spare rear wheel hub?