Tire Mounting Question

[rockgremlin]

The tires on my ride need replacing, and a relative has offered to gift me his slightly used tires....but they're not the same size.

Will I still be able to use his tires even though they're slightly larger than mine?

Sizing info:

His: 265-78 R18

Mine: 285-70 R17

Thanks in advance!

[devo_stevo]

Nope. The last number is the size of the wheels. His tires are for a 18" rim. You need tires for a 17" rim. So they won't fit.

The other numbers are a bit off too. The first number is the height of the tire. The higher the number, the taller the tire. The second number is the width. Again, the bigger number is wider. The R means it's a radial tire, and the last number is the size of wheel that it fits on.

hope that makes sense. it's a bit rambly, I know.

[rockgremlin]

Damn. Well thank you for clearing that up at least. :2thumbs:

[Iceaxe]

Sizing info:

His: 265-78 R18

Mine: 285-70 R17


Yeah, wrong size rims... and just for giggles...

265-78R18
Diameter 34.3"
Width 10.4"
Sidewall 8.1"
Circum. 107.6"
Revs/Mile 589

285/70R17 Tires
Diameter 32.7"
Width 11.2"
Sidewall 7.9"
Circum. 102.7"
Revs/Mile 617

[devo_stevo]

Looks like I have the info a bit backwards.If Ice's numbers are right (I've no reason to doubt them), the bigger the number, the smaller the diameter, and narrower the tire.

I got the rim size right, though. That's something....

[Iceaxe]

The first number is width of tire. Second number is height of sidewall given as a percentage of width. Third number is rim size.