I have been thinking about various after market tires and have been wondering just how much additional weight would effect the over all performance of my ATV.
(2007 Griz 450)
We know that the diameter of about an inch is not too bad, but more then that will suck up low end torque, sometimes by a lot. But how about tire weight?

My stock tires I believe weigh about 75 pounds for all 4. The Radials I'm considering are about 120 pounds for all four. 45 more pounds for 1" taller tires seems like a lot. However it's being done so frequently by so many people I am wondering just how much of an issue is it?

On my Honda 300 I jumped a tire size and it ran just as good as the stock tires. I don't recall the weights but they were much bigger tires. It was no issue at all.

So who's gone up in size and what did you notice for power loss..........Anything? Nothing to consider?

 

You can overcome the power loss easily with jetting/filter/air box adjustments. . I went with 10x12x26 front and 12x12x26 in the back.....I wish I would of went narrower ....hope that helps

 

Also remember that a tire's stated size and it's actual size are not always the same. My 25" Kenda BearClaws are actually only 24" tall. Kenda's website shows this on their tire spec sheet and my tape measure confirmed it. So the overall effects of going from 23" stockers (which are a true 23" tall) to 25" Bearclaws (in reality only 24") were very minimal. I really can't tell the difference.

 

And that works the other way to. I stuck with stock size 26" tires when i ordered my swamplites, and i gained an inch of Ground clearance. I dont regret it at all, as i have enough power to not notice any difference.

 

I just upgraded to better tires this winter on my 06' Sportsman 500 EFI, the stocks were 26" high and I went with 27x10x12 Maxxis Mud Bugs all around, I wish I woulda went a little wider in back but I like the wider tires up front. Didn't seem to take any power away and maybe gained a 1/2"-1" of ground clearance.

 

You'll notice the difference in racing, whether you are racing side by side with another quad, or against a stop watch. Handling, suspension, braking, and acceleration are equally affected, but you need to be at the limits of the ATV to notice the difference. Just cruising with a typical utility ATV is not going to be enough to be able to tell much of a difference. Put 27" radials on your quad and drag race a stock one, and you'll loose, even with aftermarket air filter, exhaust, and jetting changes. Don't drag race, or GNCC race, and it wont matter. [img]i/expressions/face-icon-small-smile.gif[/img]

We have 27" radials on our Grizzly 700, and its just fine if I don't act like Mr. Cross Country Racer Dude across the sand whoops. So if you use your utility ATV like most people use their utlity ATV I wouldn't worry about it.

 

It's kind of an interesting process this "ATV" machine. The actual name ATV gets pushed in the direction of the needs of the owner. It's called "All terrain Vehicle" but many are built for Speed, Mud, rocks, etc. Seems few are actually built specific to handle "all terrains"

For my needs the use of "all terrain" is critical. I may not be swamping it with deep mud, or racing it. But I do have every kind of situation to drive over that would be expected. I think the most important feature for me is low end grunt with minimal tire slip to climb steep hills on loose surface with slow careful speeds, often with a load of meat on the racks.

So I really don't want to lose any low end torque. My Griz comes with 25" tires so 25-26" are certainly the maximum I would use. High floatation and lots of grip are critical on the hills as well. So an inch or two wider is also good for me.

Only one tire is made 25X12X12 for the rear matched to a 25X10X12 for the front that I know of, ITP mudlights. These would allow me to keep the final drive ratios factory, but greatly increase traction and floatation. With my Griz in Low range it climbs very good( ie Perfectly). I don't want to lose that for any reason. So I could also go with the Bighorns in stock 25" tire size, however they run about a size larger then they are listed at. I have 25X8X12 Bighorns on my Rokon 2WD bike. Parked next to the Grizz the bighorns are much bigger then the 25X8X12 Maxxis factory tires even though they are marked as an identical size tire.

I guess the bighorns are about as good an all around tire as has ever been made. The mudlights give me wider tires at the same diameter though. This is a tough call, too many options!

 

i have no interest in racing, but also need to get anywhere i point it. i go to over 10,000 feet or more pretty much every weekend in the summer (usually riding double). so when we say you will have a very hard time telling the difference, it means on the difficult trails, too. i went with 27" Bighorns to get over bigger rock piles and more floatation on snow. i can climb better with them than before because the limiting factor is NOT the machines low end grunt, but the TRACTION. the larger tire provides more traction.

my first aftermarket tires on the brute were 25" Bighorns and they were dandys. but when i had a hard time getting over some rock in ticklish places, i gave the 25s to a friend i owed a favor, and put the 27s on mine. but anyway when i bought the 25s, i agonized over tire size and decided that the 25s would reduce stress and keep the gear ratio low. now i know the larger tire is better for me. just don't worry about the machine not having enough power to turn a larger tire or you may wind up giving a set to a friend and buying another set for yourself like i did.

but there are also lots of guys that do not need a big tire. so i guess it just depends on your needs.

monty

 

Thanks Monty, My 2007 Yamaha Griz is a 450, it's not one of the huge buggers many guys are running now. Maybe the 26" bighorns are the way to go? That is still over 50lbs more tire weight then I have now. In low range I have lots of power for hill climbs. I know that that unsprung weight is a lot of stress to the axles. I just don't know where the limits are at.

These Factory Maxxis tires are so thin and light. Maxxis does not even list them on their website to see what they do weigh.

The Bighorns are a very large tire for the size marked. I'll bet those 27's your running are much bigger then most other MFG's 27" tires.

 

ok, i understand about your concerns a little better. you may be on the right track with the 25s. i was thinking grizz 700.

one trick to save some weight is to use the narrower front tires on all four corners.

the 25s i had and the 27s i have now are pretty close to true height with the lower pressures i like. 3-5 psi usually.

monty