I measured my tires two different ways and came up with the same figure for the Trail Tech. Tires are at stock pressures, 4.4 lbs in the front.
First I put a straight edge across the front of the quad and measured up from the ground. I got 20.55 inches. I multiplied that by pi, then by 25.4 to get 1635 mm.

Then I took it out and did the tire rolling measurement. Marked the tire and the ground. Rolled it one rotation and measured. I thin it came out to 64.5 inches, but I don't have that with me. Multiplied by 25.4 and came up with 1638. So, by cross checking I came up with what I'm going to use, 1635.

Hope that helps all of you guys.

 

Due to the tire having very little weight on it and tire growth at speeds I have come to
1703 as my setting on a Raptor ( which has the same tires on it ) and have checked
the readings with a Radar and GPS many times and they are all right on.
Hope this helps you out. Don't know if you have anything to check it with ??

 

Same tires? I didn't know that. You checked with GPS? That must be right then. I know for sure the tire hard to grow, so this helps a lot. Tire pressure and rider weight might affect it too.

I'll try 1703! (It'll mean I'm going faster).

Last night I got it way up over 60 with 1635. Looks like about a 4.1% increase. 70 something for sure.