[Sicko]

Hi....I have a 1979 GS1000.

I want to up size the rear tire. Can any one tell me what is the biggest size tire I can fit onto the stock mag wheel;
The lettering on the tire says MT 90 B17 76H.
It looks like a fair amount of room. By the way it's a chain drive in case that matters.

Thanks so much

 

[Section_59]

Hi....I have a 1979 GS1000.

I want to up size the rear tire. Can any one tell me what is the biggest size tire I can fit onto the stock mag wheel;
The lettering on the tire says MT 90 B17 76H.
It looks like a fair amount of room. By the way it's a chain drive in case that matters.

Thanks so much

One size up from standard is all that's safe on standard wheel

We dont use those Tyre sizes over here in the UK (No one does after 1991) so i had to look up the tire size .... and thats easier said than done lol


MT90 is a 130/90

B is Belted Bias

17 Rim Size

The 76H is the load Index 76=882 Pounds and speed index H=130mph

So converted into the sizes we use in the UK Its looks like standard is a 130/90/17 HB

The 90 in the size can be changed as that's the height of the walls and the most common for that size of tyre seems to be 80

So you should be able to use either

120/70/17 Smallest
130/80/17 Standard
140/80/17 Biggest

 

[Jackstand Johnny]

I agree with Section. Sometimes what you have is as wide as you can run but in most cases you can go one step or. In fewer cases you can go 2 sizes up but then you run into problems like the side profile crowning which can be disastrous through a turn.

Also one thing to keep in mine is that two different tire manufacturers with the exact same width tire, will sometimes actually bear two slightly different widths. What I mean is some brand tires run a hair wider than others with the exact same profile stamped on them both. I hope my rambling has helps a bit...SHO US PICS OF YOUR BIKE!

 

[little13]

Why don't you consider putting on a wider rim?