Motorcycle wheel size: 80/90?

Question

I want to buy a new tire for my motorcyle (honda xrm, wheel size = 17) but im bothered about the 80/90 written on the wheels. Is the 80 = width, 90 = height or vice versa? please enlighten me.

Answer 1

80/90-17

Tire is 80mm wide, height from rim is 90% the width (1st #) and rim is 17" diameter.

None of these #s have anything to do with tread type.

Answer 2

80/90 is type of tread Probably sport touring thats what i use to use on my dynawideglide. i know 70 is same but more agressive like road bike tire!

Answer 3

similar to car tyre sizes...185/60/14...185 is the tyre width  60 is the profile[hight]  14 is the dia[wheel size]...best bet is to stick to the same size thats fitted.