1980 GS 450 Tires

[John Mellencamp]

Okay I was ready to order my tires after looking at the Haynes manual and converting the old size to the new metric size giving me Front - 90/90-18 and Rear - 110/80-18 . So just to check to see what was on my bike and they are completely different . I have 90/90-19 am20 on the front and 130/90-16 Challenger tire on the back . The front looks to be the correct size but the rear only has a few mm clearance from the swingarm and bracket on the other side . On the avon site it lists 130/90-16 as the correct size but looks a little close to me . The rim says 2.15 X 16 .

[Steve]

As for the difference in sizes, are you sure you are reading your manual and your bike correctly?

The sizes you say are correct in the book sound like they might be for the 450 or the 450S.

The sizes that you say are on the bike sound more like a 450L.

Obviously you can't go any bigger on the back, but you don't want to anyway, with that 2.15 rim.
Not sure if anybody makes a 120/90-16 rear, but as long as you have clearance with the 130, go ahead and get another one.

For the front, the stock size might be 90/90-19, but many of us run 100/90-19 to reduce (or eliminate) the typical speedometer error in these bikes.

.

[John Mellencamp]

You are correct it is a 450L . I was just a little concerned about the clearance in the rear not use to having a bike like this .

[SqDancerLynn1]

It would probably be happier with a 120/90/16... 16" rim should be wide enough for a 130

[bwringer]

Duro, Kenda, and IRC make 120/90-16 tires, which would be somewhat closer to original.

130/90-16 is a helluva lot easier to find.