Having just gotten back from a very "rocky" ride with cowboy, I can tell you that an IRS set up would have sucked. It would have been better for comfort, but beyond that I wouldn't have wanted it. When your in the big rocks, with a straight axle if you lift one, or both sides, the whole axle raises. With an IRS, the outside wheels go up, and the center goes down. Then along comes Mr. rock. Can you spell dent, bent, or broken?[img]i/expressions/face-icon-small-smile.gif[/img] Not only that, when I came to a very high rock in the path, I just off centered it on the rear and I had lots of clearence. An IRS would have hammered the A-arm in the rear! This isn't to say that an IRS is a bad set-up, I just think that it has its weaknesses. Rocks are one of them. Mud is another story.

Rick

 

The irs always has 2" more ground clearance to start with, so if you dodge the rock with your diff the ind wouldn't have touched anyway!!! I have a 300 Cat w/ind & it clears any rock the 500 Cat does. The act does have advantages for work related stuff, but for ride & clearance IND sus is always better. At least in my opinion.

 

Pechmial

Arctic Cat claims 10.75" of ground clearance at the frame on the 400, and I personally measured 11" at the frame. The rear diff is something liked 8.25-8.75," I have it in my tablet. But I don't have my tablet with me.

 

sxr6,
I wasn't sure about the clearence figures between a straight axle vs. an IRS from the inside wheel hub to the differential skid plate. So when I was at the Yamaha dealer this afternoon to buy another CV boot for my quad, I took some measurements. From the ground up on my quad to the axle housing next to the inside wheel hub is 11.75" On the IRS Griz its about 8.75" to the a-arm connection. That is 3" less than what I have. More than enough room for a rock to do some damage. 6" in from the wheel my quad is still at 11.75".The IRS Griz is at 11" there. I didn't even bother to measure the IRS Griz at the center, as it was clearly better then I was. The point I'm making here is that those rear a-arms coming down from the center to a point less then half way up the rear wheel center is a limitation in certain circumstances.

Rick