Some other RZRs had added an aftermarket aluminum clamp over the exposed axle, that was supposed to eliminate axle flex, which they claim leads to CV failure. I am not sure that I can get my head around that idea, but will investigate further. The product is made by KNINE products, and it looked like a clean installation.
At this point in my investigation, I believe that I am leaning towards the Dragonfire Racing HD Rear axle half shaft/CV joint combination. Both the axle and the CV joints are beefed up, which should provide greater overall strength to the system. My only concern is that the transmission would now be subjected to more stress with the stronger axle/CV joints.
I will keep the thread updated as I proceed.
I'll chime in, I'm one of the engineers behind the KNINE's. I'm a big fan of Summers Bros stuff, and like a few others here, would recommed that set up in a heartbeat. They know what they're doing. The 570 joints are same material (55 cup/20Cr internals) as stock 900 joints, but have a bit larger range of operating angle, and larger splines, which allows more options with shaft diameter. More than anything, the axle shaft will determine how well your CV joints hold up. You can have the biggest, strongest joints on the planet, made from the best alloy...infused with Chuck Norris's DNA...but if the shaft design is no good (for the application), they'll grenade worse than the stockers if you're pounding whoops, jumping, etc...with the pedal down.
"Both the axle and the CV joints are beefed up, which should provide greater overall strength to the system."
...here's where you have to be careful, and most guys have this completely backwards. Beefed up CV joints are great, but a beefed up axle will provide LESS OVERALL strength to the system. Unfortunately, these 'heavy duty' axles have kinda taken over in the last couple years because they are actually easier to sell/market and cheaper to make...and that big 1" axle shaft fools a lot of people.
Summers Bros (and several other high end brands) look like the correct 'necked down' shafts below, same as stock 900 shaft profile/design, but SB are high quality alloy (4340 or 300M) and the stockers are carbon steel. Alloy is not 'stronger' in the sense that it will resist twisting more than the stock shaft; this is a good thing. Both the alloy and stock shaft, of same diameter, will twist to the same degree, under the same load. BUT, the alloy has the ability to go to an even higher degree of rotation and 'spring back' to normal when load is released. But, if the shaft is not designed to do this, it's just a waste of good alloy. Here's what it all looks like...
"...to eliminate axle flex, which they claim leads to CV failure.I am not sure that I can get my head around that idea, but will investigate further. The product is made by KNINE products, and it looked like a clean installation."
No worries, some guys seem confused by these yet. Even though there are a ton of them out there. We are taking the correctly 'necked down' shaft and going a step further with it. As you can see above, the necked down shaft is far superior in eliminating torshional (torque) loads to the joints, but in doing so...the shaft will bend/bow out of shape violently, but it's more of an impact, like getting hit with a giant hammer as the tire slams the dirt...and it's doing this constantly. It's a combination of both torque loads and the violent suspension cycle.
Imagine pounding a whoop section or landing a jump...here's what's really going on back there and the forces on the axle.
Now here's with the KNINE's. It's so simple and so effective. All we're doing is first allowing the use of a much smaller diameter, 'necked down' axle shaft...and secondly, we are 'dampening' the blow to the entire system...which shoots through the shaft. All we really care about is reducing as much stress to the joints as possible, however you want to describe it.
