[extra300]

Why is it in every video I see, when this thing goes off a jump, the nose instantly points towards the ground. I have watched about 10 different videos and this thing is way out of balance? No?

 

[clemson726]

i believe its supposed to be biased to the back 55%. I dont know what it is with the driver in it.

 

[rwillden]

This has been discussed before... If you jump anything, and let off the throttle after the jump, the inertia of the tires stopping,or slowing nose dives the vehicle you are jumping. I jumped my Rhino (which is way front heavy) all the time, and as long as I maintained the throttle through the jump, it landed smoothly every time.

Every video you watch where someone jumps a RZR and it nose dives, if you listen, or watch closely, you can hear them let off the throttle either right before, or right after catching air. The inertia is what causes it a majority of the time.

Newton's first law: An object’s inertia causes it to continue moving the way it is moving unless it is acted upon by an (unbalanced) force to change its motion.

Read this thread for more info, videos, etc...

http://www.rzrforums.net/general-rzr-discussion/31489-rzr-goes-big-wrecks.html

 

[SomeGuyFromOlympia]

its all in the gas....

 

[Chino]

depends on the jump too.. short steep ones will buck you.. long gradual lips will throw you farther and more even..

 

[leadfoot2]

i have to back my 2010 on to my tilt trailer , if I drive it forward the trailer won't tilt,,,,,,,,,,,,,,I'd say it was back heavy

 

[FunRide]

Why is it in every video I see, when this thing goes off a jump, the nose instantly points towards the ground. I have watched about 10 different videos and this thing is way out of balance? No?

Too funny. I was literally just about to starting typing the EXACT same post. I've seen nothing but RZRs nose diving into the dirt as well. I've seen them flip over nose first (endo)....ugly driving.

Here is what I think is happening, in many cases:

The driver picks a jump then heads for it.....he's on the gas until the last critical second and lets off the gas. This mild engine breaking causes the nose to drop when the front end tries to lift off. I've seen it over and over on You Tube. The machine needs to be launched forward so that the rear tires are pushing you right off the edge.

If one is jumping a dirt bike you need to keep it hammered all the way off the end of the jump. You can't let off the throttle until the rear wheels are clear. It gives the machine that slight little push to propel the front end forward. It's similar to skiing....When one leaves a jump, you give a little push forward that help project your body so you don't start to drop immediately.

I think one should be on the gas upon landing as well to help smooth it out. If the wheels are virtually stopped (engine breaking) it makes for more stress on the transmission on impact and less control.

This is just a concept from what I've noticed in the vids....others may have a different idea.


Edit: Looks like others agree with what I'm saying. Posted this before reading others.

 

[cwspfx]

 

[caulk04]

Ehh, I think it's just as much the stiff rear suspension that does it. Not that I do much jumping, but I understand the throttle concept.

Anyone ever notice how if you sit on the front bumper, it just about bottoms out but if you sit on the bed, it barely moves?

 

[cwspfx]

The fly great .... with the right launch pad and enough speed!!

watch ... you can see where I lifted off the throttle .... about half way!!!

 

[Langford]

The fly great .... with the right launch pad and enough speed!!

watch ... you can see where I lifted off the throttle .... about half way!!!

Exactly...if you have a long enough "ramp", and you keep on the throttle...they fly great. I made the mistake of not letting off of the throttle at all...lucky I didn't grenade the rear diff:

 

[Sparafucile]

It definitely has to do with throttle but just as much to do with the actual jump. With a short jump, as the rear suspension compresses from the transition onto the ramp the jump ends (air time) just as the rear suspension is rebounding from the initial compression, basically pogo-sticking the back of the vehicle upon takeoff which results in the nose dropping. On a longer jump the suspension has time to fully rebound from the transition onto the jump before the jump ends which avoids the pogo-stick effect.

Actually the rear-weight bias of the Rzr makes the problem even worse. The more weight over the rear means more compression of the rear suspension from transitioning onto the ramp which in turn means more rebound force and, well, there goes the back end into the air again. It's one of the reasons I very much wish there was a rebound adjustment in the suspension as increasing rebound damping would greatly help this problem.

The same thing happens on a motocross bike--if your weight is too far back on the bike on takeoff the extra-compressed rear suspension will cause you to endo. Thankfully a nice handful of mid-air throttle has a very pronounced effect of bringing the front end of the bike up. The Rzr has the same ability though nowhere NEAR as pronounced as with a bike.

 

[FunRide]

It definitely has to do with throttle but just as much to do with the actual jump. With a short jump, as the rear suspension compresses from the transition onto the ramp the jump ends (air time) just as the rear suspension is rebounding from the initial compression, basically pogo-sticking the back of the vehicle upon takeoff which results in the nose dropping. On a longer jump the suspension has time to fully rebound from the transition onto the jump before the jump ends which avoids the pogo-stick effect.

Actually the rear-weight bias of the Rzr makes the problem even worse. The more weight over the rear means more compression of the rear suspension from transitioning onto the ramp which in turn means more rebound force and, well, there goes the back end into the air again. It's one of the reasons I very much wish there was a rebound adjustment in the suspension as increasing rebound damping would greatly help this problem.

The same thing happens on a motocross bike--if your weight is too far back on the bike on takeoff the extra-compressed rear suspension will cause you to endo. Thankfully a nice handful of mid-air throttle has a very pronounced effect of bringing the front end of the bike up. The Rzr has the same ability though nowhere NEAR as pronounced as with a bike.

Good explanation.....definitely more than just throttle going on. Avoid short jumps with a standard RZR (no adj. rebound damp) and stock suspension. I guess you can just leave it mashed the whole way down and try to bring it back a bit.

 

[FunRide]

The fly great .... with the right launch pad and enough speed!!...lucky I didn't grenade the rear diff:

Nice smooth jump and landing. So Lang you are saying to let off on impact? I would think you'd want the rear wheels spinning some so there isn't as much force on the diff when it hooks up? Let say in dirt conditions.....not sand.

 

[Langford]

Spinning some is fine, but you don't want to land at wide open throttle bouncing off the rev limiter like I did...very good way to snap an axle or grenade the diff or trans. If you keep on the gas until right before you land, you should be good...it wont buck forward on you and you wont be so likely to break things.

 

[FunRide]

.....If you keep on the gas until right before you land, you should be good...it wont buck forward on you and you wont be so likely to break things.

Roger that.

 

[cwspfx]

Let me just say ...

That jump is one in a thousand ... I have been to allot of tracks out here on the west ... and 99% of the jumps dont fly or land like that one! 99% of them ... we are landing on the front tires !!!

I dont care what you do with the throttle ... if the jump is not right ... you just load the suspension wierd!

Just like Sparafucile posted!!!

plus a broken back CV doesnt help!! thats why it turned off the jump!!

you should have seen the camera guys eyes!!! he missed a few frames!!

 

[FunRide]

Let me just say ...

Brutal landing......Don't know how the machine withstands impacts like that over and over in a racing situation. You'd think it would just fold in half and send the driver through the windshield.

 

[cwspfx]

its not as hard as it looks ... but things do break ... I have just about chased all the gremlins away ... I HOPE!!!

lets just say .... there is nothing from Polaris on my suspension ...LOL!!

 

[FunRide]

its not as hard as it looks ... but things do break ... I have just about chased all the gremlins away ... I HOPE!!!

lets just say .... there is nothing from Polaris on my suspension ...LOL!!

That is impressive engineering. The forces those components endure is hard to comprehend. That third photo is just scary.....literally looks like the machine is about to break in half. -That's a sick ride.