Hey guys, quick question.
What would be the wheel size or general number that I would put into my cycle computer for a “Duro wildlife leopard 24” x 3.0".
Thanks.
I use 196 cm for my 24" x 3.0" Nokian Gaz.
You could measure it pretty easily…
I use a piece of chalk and mark the tire and the road, right down there where the rubber meets the road. Then roll the wheel until the chalk line on the tire goes around once.
Take a tape measure and measure from the first mark to the second.
Convert to metric as necessary (cheat with an online converter).
I don’t know if there’s a standard for cycle computers, but I think most take either millimeters, or millimeters/10, or millimeters*10, or something.
It should be pretty obvious based on the default number that the computer starts with, or by looking at the general chart in the manual.
Of course with a fat muni tire like you have, the number will be closer to a average 26" tire.
I’m told that you will get a more accurate reading if you are on the uni when measuring the line. Depending on your weight and the amount of psi, any compression of the tire will change (reduce) the length of each revolution.
This is how my lbs determined the proper calibration for my cycle computer on my 36er. To make sure it was accurate, I compared it to readings on my garmin, and it was spot on. It would have been off considerably if we had not measured the full revolution without me on the uni.
An easy way to do this by yourself is to put a dab of something on the tire (sunscreen, yoghurt, toothpaste, etc) then pedal a bit and measure the distance between the spots left on the ground.
I just start with the tube stem at 6 o’clock and go one revolution to the same point.
On my 24"x3" muni, I found a 2" reduction when I moved my uni one rotation with me on it, versus without my weight. So I confirm the above.
Then I tried a high psi (35) and a low (20), both with me on it, and I again saw about a 2" difference, from about 78" to 76".
That’s a 2.56% reduction.
So, if I calibrated with a different PSI, my computer might say I went 10 miles, when I actually went about 0.25 miles less.
In 100 miles, I would have gone about 2.5 miles less.
Not a big deal to me, but I did the math so I thought I’d share it.