Does anybody know of a resource that will not only tell you the manufactures “advertised” tire size but also tell you the "true" measured size. If I pay for a 27” tire I want a 27” tire. Do you agree?

 

Just curious but doesn't air pressure effect tire size? If a manufacture sells a tires that claims 27" then you would need to run the same air pressure to achieve that rating. I don't know of any standard air pressure, tires are set at to be measured. There may be an article in one of the ATV magazines that would give this information. Good luck it would be interesting to see a chart that would not only give the tire size but the weight also.

 

I am or was leaning torwards the Titan 589's but real world comments like the one below really are making me rethink things. This isn't just limited to the ATV world either it happens with truck tires to. I just think it would be a good tool for deciding which tires to buy. And yes tire pressure will affect the measurement as will if the tire is on the bike or off. Rim size will effect this also.

Comments from: Maiden Voyage, CAT 500/Titan 589's

"The actual size of the 26" 589's is 9.5 wide on the front and 10.5 wide on the back. They are not even close to the 12" stated rear width as advertised."

 

Yes, tire pressure does effect how tall a tire CAN be-for instance, look at Boners 29" Tri-Claws. Granted, they're a stated 27" tire at the RECOMMENDED psi, but with 35 psi as Boner has, yeah, you can get a taller tire. The manufacturers claims I believe are under their normal suggested pressure on the wheel, but off the machine. As for the rest, to my knowledge the Bi/Tri Claws are the only tire that actually measures AT LEAST the stated 27" size at recommended psi. As I've said before, I say AT LEAST because at recommended psi, mine actually measure between 27 1/8", and 27 1/4"-thus, more than the stated 27". The new Titan 589 M/T's are claimed to be a "true" 27" size, which would be good to see, but as the width of the tire is now in question, I can't say for sure on that one.

Yes, I definately agree with you-if I'm going to pay for a tire that is 27" tall, I want a tire that actually measures 27" tall! I've seen a lot of guys with both mud bugs and the old titan 589's in the 27" size, which actually only measured a hair over 26", and not near the 12" wide rating either for that matter. Hell, my stock titan 489's which were claimed to be 25", only measured 24 1/8" at recommended psi. Does that make them a bad tire? No, in my opinion, the 489 is a great all-around tire. However, when you pay for a 27 incher, you want a full 27". Granted, 1" lower in true size may seem small, and the half-inch gain in clearance you'd get from that extra inch in size may seem even less significant, however I have been in places where that extra little half an inch of clearance meant getting through, or finding an alternate route around. It will be interesting to hear if the new "mudzilla's" are true to their claimed 28" size.

Best of luck in the search, look forward to your findings.

Mike

 

DakotaCat, do you ride with Mike, Rob, and them in Rockwall?

Tire pressure and rim size will both affect tire shape. My 27x12x12 mud bugs with 10 PSI on 12x8 wheels measured 27x11.

 

Yes sir I do ride with those folks, I see you guys had a pretty good time in Athens. I spent all Friday night wrenching on a SP500, Then he BURIED it in a drained pond. And I agree 100% rim size (width) and tire pressure will effect the measured size quite a bit.

 

Cool, I couldn't remember everyones names (I have them writen down at home and I'm at work).

 

You might try Goodyears web site it has the the sizes and specifications on the Mudrunners Check it out

 

I have 27x9 & 27x11 ITP 589's and they are 26.25x9 & 26.25x11, with 6.5 psi. on the factory rims of my 01 500a. I'm sure you could get 27 + with more psi. But they are alot closer than the 27" vamps I had on my 98 500. they also ride alot better and perform just as good or better in all conditions.

 

Because rubber needs to cure and compounds vary, so will tire size. I think I had one of my claws that was a 1/2" shorter than the rest at the same psi.

You can also stretch tires too. I am doing this to my claws now. You put alot(30+psi) and leave them out in the sun. The Sun softens the rubber and heats up the air inside them, this makes the tire grow. And in most cases it will hold this overall tire height with normal psi.

So if you are not satisfied with your tires, air them up to about 35 psi, set them in the sun for a couple of hot days, then bring them in the shade to cool for a couple hours, then let the air out. They should hold the larger size with normal psi.