'77 GS 750 Rear Tire

[rhoff71]

I'm looking at getting a new rear tire for my '77 GS 750.
The one I have is a 120/90 18. Is this the OEM size?
How wide can I go? I beleive the rim is stock at 2.15 X 18.

Thanks

[Romero]

i think the widest you can go is 4.5 inch wide back there

[ptm]

The stock tire was a 4.00 on a 2.15 rim. Most fitment charts I've seen show a 110 as the biggest tire you should put on a 2.15 rim, but the 120 I have on my 750 works fine. I measured the old 4.00 that was on the bike when I bought it and it was the same as the 120, although exact width will vary by manufacturer. I wouldn't go any wider - the 120 is really close to the chain guard.

http://www.avonmotorcycle.com/us/en/Product.asp?ProdType=TouringXply

http://www.motorcycle-karttires.com/product/fitment_guide_2003/index.asp

There's another non-manufacturer site, but I can't find it.

[rhoff71]

Thanks, I didn't think I could much wider but I was
curious what the original size was.

[earlfor]

I used a 120 on my 79 750E. it handled just fine with that tire. I dont think a 130 will fit as in checking measurements on a 130 on my other bike, it was so close, I couldnt predict for sure if it would rub or not. Besides, a 130 is probably not a good choice for a 2.15 rim.

Earl