This debate looks like it could get to be interesting I am no engineer in metals but it does appear that square tubeing would be the stronger. looks like it would be harder to bend than the round tubeing, exactly what kind of bending and where does this happen at on your bike I have had mine in some hell of places and have never felt the frame give any....

 

I too have heard from my years in the mountain bike world that square tubing is stronger than oval, but square tubing looks foolish on a bike frame. As for flex wow I have never felt it and I drive pretty hard. Though to be honest I have sene people doing things with there atv's that is almost borderlining on atv toture! LOL

 

Ok, Let me be a little more specific.... If you compare the quality of the round tubing Yamaha uses to build their ATV frames with the quality of the square tubing that Polaris uses to build THEIR ATV frames... POLARIS FALLS WAY BEHIND!!!!..
It kills me to say these things (because of my disgust for yamahas) But, it is the truth. Maybe Polaris could continue to use square tubing... just get some better quality stuff or maybe redesign the frame geometery?????.. Im not greedy, just make them feel a little more rigid and you can build it out of recycled beer cans for all I care...
My bike seems to "sag" when Im really trying to move at a good speed thru really rough terrain. such as when the mudholes are drying up and youre riding on old rock hard mud... And when you are IN a deep mudhole and the bike is "torqued" out of shape... By that I mean rear of bike almost under mud, rut is meeting dry ground, and your bike is leaning so far to one side that its about to fall over.. One front wheel is WAY off the ground..and youre clawing your way out...
Ok, better Idea, just build an "East Texas Bubba Mudder Special" equipped with a cooler, 34" tires, no exhaust, CB Radio, Rebel Flag flying from rear, Dual drinkholders..(THANKS PFLECT!!!) More PVC Pipe than most of us have in our mobile homes... ETC...

 

The reason (actually, this is what I think) polaris doesn't use round tubing is because it is almost imposible to have a robot do a good quality weld on round tubing. Just check out the article under product reviews on atving.com about the company who makes after market 250r frames.