A machine with IRS will way outperform a solid rear axle machine in all of the above, especially rough terrain. This past labor day weekend, a group of us were riding in the Big Horn Mountains of Wyoming. One hour into the first day, one of the guys riding a Honda Foreman tipped his quad over on the rocks and broke his arm. He now owns a quad with IRS.

 

that is not true, and I'll take some of what I posted from a different thread on this subject.

There are some disadvantages to IRS such as when ridden aggressively or side hilling as they feel tall and tippy, and even with sway bars they have a lot of rollover in corners, and the extra weight from all the additional drive-line and suspension parts - and maintenance.

The roll is accompanied by a moment working to the bad side of the COG on side hills.

bigger roll, softer ride, bigger moment, less stable (current ATV IRS)

less roll, stiffer ride, less moment, more stable (current ATV SRA)

The IRS ATVs I’ve driven obviously have a roll center that is not the same as the CG height, so there is a roll moment. With current ATV independent rear suspensions that do not limit the roll as much as an SRA (so they ride better) - there is less roll resistance or roll stiffness. So you get more roll and you come closer to your rollover threshold due to a higher roll moment, a lateral shift (and increase in height) of the CG, and suspension compression on the low side that leads to a further shift in the CG by moving the contact patch closer to the body reducing the track width. Shifting your weight can shift the CG back some, but there is still more roll and roll consequences with the current ATV IRS. SRA is more stable in off cambers and pushed to extremes the one with less roll will be more capable in off cambers.

As this roll moment is upsetting to the vehicle control system (driver), many find this an undesirable situation and feeling when riding off camber.

If your buddy rolled an SRA, he'll be more likely to roll an IRS with his skills.

 

Propnut, thanks for that explanation. Thats seemed similar (but easier to understand when in writing) to what the sales guys were saying.

We are really excited to get some seat time on these. It's funny, now I am just waiting for a big snow so I can have some fun clearing my driveway for once! We were also impressed with the Honda tranny and reliability. We had ridden a friend's Foreman before and did not find it uncomfortable at all so that is ultimately why I got the Rubicons when considering everything else.

Thanks again for the input. Helps confirm the decision.

 

On the Rubicon if you haul a heavy trailer the hitch is hooked to the rear diff. and with a solid axle the rear of the quad will not squat and make the front end light. An IRS hitch is hooked to the frame a heave trailer will make the rear of the quad squat and the front end very light.

A straight axle quad is best suited for hard work.
IRS quads are best suited for cruising around on and some light work.