New knobby sizes

[gasgasman]

I must have been under a rock.
There is a new tire size measurement for knobbies.
The old way was knobby width.
The new way is carcass width.
Here's the conversion.

Front:
Metric Old ....................... Metric ......................... Inch
60/ 100---------------------- 90/ 80----------------- 2.50/ 2.75
70/ 100----------------------90/ 90-------------------2.75/ 3.00
80/ 100---------------------100/ 80-------------------3.00/ 3.25

Rear:
Metric Old.........................Metric....................Inch
80/ 100-----------------------80/ 90------------2.50/ 3.60
90/ 100---------------------110/ 80-------------3.60/ 4.10
100/ 100--------------------120/ 80------------ 4.00/ 4.10
110/ 100-------------------130/ 80--------------4.00/ 4.50
120/ 100-------------------140/ 80---------------5.00/ 5.10

 

[ScottyR]

Dunlop, Bridgestone, Maxxis etc... all use the old way of measuring a tire for regular off road knobbies. Michelin is the only company that I can think of who uses the newer way to measure their tires, but at least they put a sticker on them with the old measurements so the buyer isnt confused.

FIM/DOT tires are another story. I think all the manufacturers of FIM approved tires are using the new way of measuring tires. I also have noticed that their isnt a 110/100-18 offered in a FIM tire most companies only offer a 140 (120) or a 120 (100) tire.

 

[jeffd]

Note that the michelins that come stock on the gasgas are "metric".

In the U.S. - for a few model years - someone mistakenly spec'ed out a 120 width off-road michelin tire as oem on the DE/XC models. This is a 100 width tire in traditional measurements - suitable for a 125cc bike.

Just a note to those at BMG/dixie sales - the gasgas off-road configuration should come with a 130/80 X 18 off road michelin tire in the rear - I prefer s-12.

jeff