The weight difference is more of a concern than one inch change. Also, going to a 14 inch rim and only one inch bigger will result in a rougher ride due to less sidewall.
Tire weight makes a huge difference in performance. Like was stated, the 570 has a harsh ride already so adding lower profile tires is not going to make it more plush.
Yes, tire weight in conjunction with taller tire is a huge factor. In the other thread, I said that was exactly why went from a heavy 35lbs/tire RipSaw set up to a 21lbs/tire setup. With the heavier setup, if you run it in high and take long steep hills, your machine will lose steam without a clutch kit. Problem is, the clutching only does so much. It give and take. I had to compromise my top end and hit Rev limiter at 48mph (10 mph less than stock setup), but my low and mid power band was fantastic, arguably faster to 30 than stock. I started running with more 900 groups and wanted a bit more speed on logging roads as that's what these groups preferred. I went to Denniskirk.com and research a lighter rolling stock setup and came up with a setup that was only 1/2 shorter tire but shaved a total of 65+ lbs in wheels and tires. With only 45hp, it allowed me to change clutching so that my power and was very even all the way across as well as my 58mph Rev limit.
Think about what your driving preferences are, terrain you travel, and how you use your machine.
I use mine to hunt in the fall, but run mountain road and trails with a kayak strapped on top to fish during the summer, and desert running in the winter. My entire setup including doors, windshield, etc are setup to meet these preferences. I never went for a look. I'm more of a function over form kind of guy.
I run 27x9x12s Terrabites on all four corners. I pull 57 mph all the time - the last 2 mph come on slower than the the first 55 mph. When I 1st took out my 2017 570 EPS I was bummed out by the lack of clearance and put a 2 inch hi lifter kit on an changed out the tires - 3000 miles later I couldn't be happier. No clutch work and run all over the inter mountain west at elevations up to 12,000 ft.
Most of my riding is in Southern Az so I love the 8 ply tires - cactus spines and sharp rocks and no flats yet.
Incase you were looking at the Tusk Terrabites I just ran across the weights for the sizes you would most likely run on a 570. I have these on my 570 and like them but I wish they were a bit lighter. I went from a set of 26" bighorns to the 27" Terra's and my first thought was "Woah, these are heavy" as compared to my bighorns on the exact same wheels. I never felt I needed a clutch kit with the bighorns but I am looking at getting one now that I have the Terrabites.
From Rocky Mtn Q&A:
Will these tires be to heavy for my 570 rzr? I currently run 27" Bighorns Brad on Aug 25, 2016
BEST ANSWER: Here are the weights of the different tire sizes from which you can determine if they would be appropriate for your application.27x9-12 - 30 lbs.27x11-12 - 32.7 lbs.28x10-14 - 32.8 lbs.30x10-14 - 34.9 lbs.
Thanks a lot I am lookin at the 26 x 9 12 for the fronts tusk trilobites they look like big horns do you think they are pretty light an a good one to pick .
Look at the Maxxis Ceros they are super light and very capable. Only downside (if you want to call it that) is that they are a directional tire. Here is the data sheet from denniskirk.com
Maxxis Ceros
Thanks do they ride choppy on hard ground or pavement an are they a lot smooter than stock tires im lookin for something that rides good an handles well I like the way they look.
My Maxxis Coronados are radial, and ride like a radial tire ie: they track well and stable at speed. I've never driven with the stock setup, mine had Sedona RipSaws on it when I bought it. I think the Coronados ride differently than the ripsaws partially due to the Coronados being a rounded shouldered tire like Bighorn, and the RipSaws haveing a definate squared shoulder. That's also why the 26" Coronados are only less than 1/4" shorter than the 27 inch RipSaws, but the riding dynamic with different shoulder shapes are only part of the experience.
My suggestion is that you research verious types/shapes of tires and see what type of tire works best with what you do and how you ride. Either way, it's $400+ for a set, you might as well get what you want, not just how they look. Function over form.
To answer your question tho, they ride very smoothly, but I'm also running Bandit shocks which contribute more smoothness than the tires.
Well there is a pretty big difference between rotating weight, sprung weight, and unsprung weight, so yes you can tell a difference with heavier tires vs lighter tires and riding alone vs having another adult in the vehicle with you.