# Tire size

I’ve been doing alot of searches and reading but still have a question. My 29" unicycle tire is 29". My 24x3 is 26". It is a duro tire…so how tall is a 26" with a duro? I’ve also read that the 26 Oregon is about the size of a 29 and just as hard to handle. It’s confusing.

If I remember correctly, my 26" duro is around 27" or 28". Not quite 29er size, but not far off. I think they measure the diameter from the inside wall to the inside wall, so the wall thickness and tread will make the tyre thicker than it should be.

Yep, wheel size depends a lot on the tire being used. My 26" with a 2.4 Continental Trail King measures 27.5". The Large Marge / Larry combination is right about 29" but a hair smaller than the 29x2.2 wheel I just built up to use in the same frame. The ride difference between the Large Marge / Larry wheel and the 29" wheel is huge. The 29er handles and climbs much easier but Larry devours obstacles.

I have a theory about the true diameter of a tire. The theory is that the diameter of the tire is (diameter + tire width - 1). So for example, a 24"X3" would really have a diameter of 26". A 24"X2" tire would really be 25". A 24"X1" would truely be 24". Same idea goes with 26" and 28" tires.

What do you guys think? In my experience it turns out fairly accurate.

A fairly accurate way of estimating what the diameter of a wheel will be is BCD + 2x width.

The actual BCDs of 20, 24, 26, and 700C/29 are: 406, 507, 559, and 622mm respectively, or approximately 16, 20, 22, and 24.5"

I’ve got a 26 x 3.0 duro on my 26er and a 29 x 2.3 stout on my 29er. There’s about an inch and a half difference.

My 24 DX is ~21/21.5" outer rim to outer rim.