Since current UTVs all suffer from lack of power in the
dunes, we have decided to take a hard look at what performance gains can be
had with different tire scenarios.
There are a few principles that we will look at:
-
Tire + wheel weight: Plain and simple - weight robs
power. The lighter the rotating mass, the less power it takes to
make them spin.
-
Float: Tires need a large enough footprint to stay on
top of the sand. A narrow tire will dig in and be less effective.
-
Traction: Sand cars and high performance ATVs both
benefit from paddle tires in the sand. But UTVs weigh a lot more than
their ATV cousins, and don't really have much, if any more power. If
there is enough power to spin a paddle tire and stay in the power band,
it will help climbing and acceleration.
Fullerton Sand Sports has 12 x 10 Douglas Wheels specially
made for this application to increase the contact patch of the tire to the
sand.
Our "Test Mule" - Polaris RZR with stock engine, exhaust, intake and
fuel controller (ECU).
We used Test Hill near Gordon's Well for our hill climb test.
We cycled through several combinations of front and rear tires for our
tests.
For all the tires we tested, two wheel drive will get
you most everywhere except the steepest hills. For hill climbing,
All-Wheel-Drive (AWD) is much more effective and necessary for the steep
stuff.
For normal dune rides, I prefer two wheel drive over AWD.
In two wheel drive, the rear end will break free and power slides are
tons of fun.
1. Front - Stock, Rear - Stock
Stock wheels and tires do pretty well in the dunes.
Our Polaris RZR could go pretty much everywhere except some of the steep
hills. The benefit to a knobby tire is durability and the ability to
handle dual purpose terrain (dune & dirt).
If you are in the dunes for any period of time, and want
better performance in the sand, paddle tires can help.
Hill Climb - I was unable to climb Test Hill with stock
tires. I made it almost to the top, but just couldn't pull the last 20
feet. Air pressure was set to 4psi front and rear and the RZR was in AWD.
2. Rear 8 Paddle
We quickly determined that our "Test Mule" didn't have
the power to properly spin the 8 paddle rear tires. This tire is most
likely a good choice once you have added exhaust, intake and fuel
controller or done more significant engine work.
RPM was lowered in comparison to OEM tires and 7 paddle
tires. The 8 paddle tire definitely adds some climbing ability over
stock, but we felt the 7 paddle was better for a stock RZR.
Hill Climb - I was able to climb Test Hill with
8 paddle rear tires in AWD.
2. Front - Stock, Rear 7 Paddle
Hill Climb - I was able to climb Test Hill with
7 paddle rear tires and stock front tires in AWD.
3. Front - mohawk with paddles, Rear - 7 Paddle
Hill Climb - I was able to climb Test Hill with
7 paddle rear tires and mohawk/paddle front tires in AWD. This combo
felt like it had the most "climbing" power.
For normal dune rides, I did not like the feel of the
paddles up front.
4. Front - mohawk, Rear - 7 Paddle
Hill Climb - I was able to climb Test Hill with
7 paddle rear tires and mohawk front tires in AWD. Speed at the
top of Test Hill was just under 10mph on the GPS (slightly lower than
the mohawk/paddle combo).
Our Favorite:
mohawk and 7 Paddle
This combination looks great and performs well.
Hill climbing is much improved over stock. Two wheel drive is a
lot of fun. The rear end breaks free pretty easy and the front
mohawks help keep the front end tracking. The extra track width
definitely increases stability, even with a long travel kit.
