Tire size

[William57]

Does anyone have experience with running a 140 on a 17 rim with the GL1000?

[William57]

Ok let me put it another way does anyone have experience with running a 140 wide tire on the back rim of a GL1000?

[wog]

I believe a 130/90-17 is the widest without cutting into the swingarm.
Here's a picture of one mounted on one of my '78's.

[Fred Camper]

My understanding is that grinding is required for every brand of that size. Some 130 width rear tires need to trim the right side swingarm. Some brands result in grinding right through and then closing it back off again. No real good reason to run a 140 other than the appearance.

[William57]

Thank you for the picture and reply Fred. As to grinding, are you saying you had to grind some off the swing arm to get the 130/90 to fit?

[Fred Camper]

Not me, but my 130 is on a 16 inch rim so it has a touch more room. I have heard one or two others mention a slight grind to use a 130 on a 17 inch rim, but it is certainly not the normal situation. But I am pretty sure all who run a 140 need to grind some, at least I have not heard of anyone to find it to fit without grinding.

[spookytooth]

Bumping an old thread! I need a new rear tire! What would be the widest tire I could mount without modification?

[Fred Camper]

130 is as wide as you can go without a specific brand. 140 width requires swing-arm mods to the drive-shaft side with many but not all brands. And since brands change molds, not sure any 140 will currently fit without mod. With a 16 inch rear, pretty much the same story. You get a bit more room, but not enough for a 140 to fit.

What brand are you thinking about. I am running a Spitfire on the back, but only about 2000 miles so far.

[spookytooth]

I'm not sure... Leaning toward Dunlop but for no particular reason.. I have a Bridgestone on the front.. I would like to get a matching set of RWL but can't really justify the cost of replacing the front which is probably only a quarter worn.. Here is a picture of the tire before the beginning of the season and another recently....

[jellyfishmoonpie]

anyone know if you can mount a rear tire on the front rim? i like the look of it.

[jellyfishmoonpie]

matter of fact, id like to be able to mount Either 120s (stock rear size) on both, or 130 rear 120 front.

[Fred Camper]

That has been done but you need to lace a wider rim on the front. I believe the most popular is 16 rear, 16 front using HD rims. The front has less limitation in width. You would need to watch the size of the front disc to the rear to see if the caliper would still fit, but if you follow what others have done then no problem.

Here is a link to a fabricator who just did the same:
http://ngwclub.com/forum/viewtopic.php? ... 37#p519637

[spookytooth]

Follow up!

So... I went with a Pirelli Sport Demon at 130/90-17. Got the Chinese tire off and found that it was a 140! The new tire is definitely narrower. It is my opinion that the bike could easily handle a 150 without modification. The real rub is in performance. The new tire is much taller significantly raising my final drive gear ratio. But that's not all! It also has raised the rear of the bike changing the suspension geometry. The fork action has definitely been affected. So recap... Acceleration reduced, front-end less smooth.

I suppose I'll just have to get used to it.