Just got my new 26" GBC dirt devils, disapointed that they only measure just barley 25" with 6lb's of air, Anyone else found these or other brands to be so far off stated sizes? Any solution to get the stated size? Whats bad is I really like these tires!

 

I have heard of that from several different sources. So I thought I'd look in to it for my self. What I found is that it is the same as with pick up truck tires- a 31x10.50x15 is suposed to be 31"tall 10.5" wide and fit a 15" rim. BUT most are only 29.5" to 30.5" tall. So thats at the very least a half an inch shorter than listed.
I've had people tell me it depends on what style of rim they are mounted on, how much air, or even how they are stored, but non of it true. They are labeled 26" as a maximum, if a tire comes off the assembly line and it is over it is a defictive tire. So this made me think about what if all tires are not the same size even from the same company???? Wouldn't hurt to check and make sure all your tires are the same size.

 

I can say there Dirt Tamer series which come from the same maker as the Big Horns, according to a tire person, are true to size, as are the bighorns, I know my 27" mudlites were not 27" ,more like a tad over 26, just wish they were sold as what they are, I wanted 26", paid for 26" got 25".