How dod you know what tire size fit's your rim?????

OK, I have an Excel rim that’s 2.15 X 18. Through searching this forum I have gathered that means its 2.15 Inch’s wide with an 18 inch diameter. Right?

The bike came stock with a 140/80-18 tire

Again I believe that means the tire is

140 MM wide, the sidewall is 80% of the height, and an 18 Diameter. Right?

Here’s where I get lost. I need a new tire; however there is a very limited selection of tires in the stock size. So, how do you know what size tire will fit on what rim? Searching this forum I found multiple posts suggesting that you could use different width tires, (IE 130/80-18) how is this possible? How does a 130mm wide tire fit on the same rim that a 140mm tire did? And how would you know?

OK, I have an Excel rim that’s 2.15 X 18. Through searching this forum I have gathered that means its 2.15 Inch’s wide with an 18 inch diameter. Right?

The bike came stock with a 140/80-18 tire

Again I believe that means the tire is

140 MM wide, the sidewall is 80% of the height, and an 18 Diameter. Right?

Here’s where I get lost. I need a new tire; however there is a very limited selection of tires in the stock size. So, how do you know what size tire will fit on what rim? Searching this forum I found multiple posts suggesting that you could use different width tires, (IE 130/80-18) how is this possible? How does a 130mm wide tire fit on the same rim that a 140mm tire did? And how would you know?

right... right... and i'm not sure...

you could probably run the 130 without any problems but i've never tried...

same reason why my 450f could run a 110/90-19 or a 100/90-19 or even a 120/90-19(thats if it doesn't rub on the swing arm or chain) the beads should all be the same size, the only difference is the tread size there is more tread on a 120 than a 100, meaning there is more knobs on the side to get more traction, thats why 250f racers race with a 110 and not a 100 that comes stock.

hope this helps.

same reason why my 450f could run a 110/90-19 or a 100/90-19 or even a 120/90-19(thats if it doesn't rub on the swing arm or chain) the beads should all be the same size, the only difference is the tread size there is more tread on a 120 than a 100, meaning there is more knobs on the side to get more traction, thats why 250f racers race with a 110 and not a 100 that comes stock.

hope this helps.

That helps, but does that mean that ALL 18 inch diameter motorcycle tires will fit that rim? No matter what the width is?

That helps, but does that mean that ALL 18 inch diameter motorcycle tires will fit that rim? No matter what the width is?

no, you could have a tire with too much width to where it hits the swing arm, rubs on the chain or when you bottom out it just dents the pipe. my dads old xr 500 runs a 110/90-19 only because the 120 is too much meat and rubs on the swing arm.

Thanks for the help.

Since my stock tire is already 140 wide I would be looking at getting a smaller tire. So it sounds like my choices are many.

Correct. I know for the XR we use 2.15X18 rear wheels.

Stock is 110/100/18

I've run a Dunlop 606 at 120/90-18 and a Maxxis IT Desert at 120/100/18 with no issues.

Look around the XR forums as thats the same size rear rim we all run and you can see a large variety of tires.

Now mind you some manufacturers use their own size system. Notably Michelin which I'm guessing is what you are running as from my understanding the only way you'll get a 140 on the rear is with a 2.5 in wide rear.

Copy and pasted according to RMatv:

Michelin size 140/80x18 = 120/100x18 Conventional sizing

Michelin size 90/90x21 = 80/100x21 Conventional sizing

Hope that helps.

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