GS1000G oversized rear tire

[Guest]

I just bought a like new 1980 GS1000G with 17k from the original owner. He was good enough to point out that although the tire tread looks great and that he had replaced the factory tires, the sidewalls are checked and they should be replaced. I totally agree and when looking at the tire sizes on the bike I was quite surprised. I owned a 1980 GS850G which had the same rear tire size as this bike, 130/90-19. However, this bike has a 140/90-19 mounted at present. I noticed this after I got the bike home and remembered that the tire width is limited by the driveshaft housing.

I checked and sure enough, the sidewall is rubbing against the housing, and it's likely been that way for 10 years. There is a heavy rather sharp "edge" for lack of a better term on the sidewall of the tire that's doing the rubbing.

My question is- is it common for guys to do this and let the tire rub? Is it possible, thought not likely, that this is not a problem? It seems to me that the tire size that the bike was designed around would be best, although it would be nice to have that extra rubber on the road albeit only 10mm.

Any input would be appreciated.

MickeyMoe

[Brendan W]

What's the bet it has removed material from the swing arm. I wouldn't have rubbing tyres.

[tkent02]

They handle like crap with fatter tires on skinny rims. Go with the proper size.

[John Park]

They handle like crap with fatter tires on skinny rims. Go with the proper size.

The more I ride wide tires on wide rims, the more I think wide tires handle like crap. Could be one of the reasons we're still here, riding thirty year old bikes.

I ride an SV650 from time to time, mostly because it gives its rider a chance to ride my GS. I'm happy to switch back; I notice he's not so eager….

Wide tires just don't dance. They 'work' better in some ways - especially for lap times at the track - but for just plain riding I'll pass. Unless you're willing to drop the inflation pressure you won't get more 'rubber on the road', just a shorter and wider contact patch. That handles more power, more weight and cools better, allowing stickier rubber compounds. It also highsides more easily, puts more offset loads into the chassis and steering. So they put the frame where the gas tank used to be and put the tank in front of your chest. COG goes higher and so on.

Not my idea of progress.

[ShadowFocus603]

First of all I'd like to point out that your tire should be a 130/90-17 not 19 just in case you try to order the wrong tire. Second, I'd absolutely go back to the stock size for all the reasons stated here.

[Mickeymoe]

Good catch Shadwfocus, I got it mixed up with the front tire. I agree with you guys, the proper tire size(s) are going back on the bike. Also, I was really surprised when I saw the rubbing because the guy I bought it from was as picky, finicky and as much of a perfectionist as me. Turns out I could slide a few pieces of printer paper between the tire and the driveshaft tube, which made me feel better. Doesn't matter though, a 130 is going to replace it...

Thanks for the input

[Steve]

And when you replace the front, consider that, while the stock front tire is a 3.50 - 19, which translates to a 90/90-19, using a 100/90-19 fits quite well, works well with the stock wheel size and removes most of the usual speedometer error.

I was going to ask how you got that 19-inch tire on the rear, but ShadowFocus beat me to it.

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