Tire sizes

[BoingBoing]

I just replaced my original Bontrager Jones ACX B 2.2 front tire with a Kenda Kinetics StickE 2.35. But the Kenda is smaller than the Bontrager was. The nominal difference is .15" that's more than an eighth of an inch! Are tires often this randomly "sized?"

BTW it's the Kenda that's off, not the Bontrager.

[bighit8]

You said it, some tires are bigger or smaller than what would seem standard.I have a 2.5 on my bighit ( Kenda klossal) and the thing is huge compared to the same size Maxxis I had!

[Pato]

The problem with tire sizes is that there is no standard for measurement. Different manufacturers measure differently. They may use different rim widths and tire pressures. Some measure the tread width while others measure the casing. This is why there are discrepancies in tire sizes.

The same tire on a 23mm wide rim will measure wider than if mounted on a 17mm wide rim. Same goes for tire pressures. Higher pressures will yield wider measurements.

Here's a third party site that gives a more comparable measurement of many of the more popular tires.

http://mtbtires.com/specs/index.html

Duc

[RED5]

Originally Posted by BoingBoing

I just replaced my original Bontrager Jones ACX B 2.2 front tire with a Kenda Kinetics StickE 2.35. But the Kenda is smaller than the Bontrager was. The nominal difference is .15" that's more than an eighth of an inch! Are tires often this randomly "sized?"

BTW it's the Kenda that's off, not the Bontrager.

Older Kenda tires, particularly the Kinetics, were not very true to size. however the newer models like the Tomac series are very true. Most Maxxis tires are another mfg that makes smaller than listeg tires, as are some WTB models especially the 2.4 Mutano Raptor.

[Schecky]

I like this rant from Shiggy:
The Semi-Slick Rant by shiggy
or how can they be faster if you keep falling off the trail?
Racing is about exploring your limits. Why lower them when you don't have to by using semi-slicks. I believe semi-slicks also contribute more to trail damage than full knobbies because of reduced traction. Semi-slick mtb tires are not suitable for 99+% of riders because they offer reduced traction when it is needed most: Under braking and descending.
Rolling fast is not worth it if you can not stay on the trail. Last year in a race I passed 4 or 5 riders as they touched their brakes, locked the wheels and skidded off the side of the trail. Not only did they lose time as they pulled themselves back on the trail, the riders left long skidmarks and a broken-down trail edge. Using full knobbies I was able to carry more speed, use my brakes effectively and stay on the trail.