How does Full-Time ATV riders with Engine Braking, keep from flipping, when riding down steep grades?
I was riding my EBS SP500, in low-range, AWD was engaged (unknowingly) going down a very steep hill, my front tires started scooting, I hit a small tree root with front left wheel, and my SP flipped! I bailed instantly,(I'm recovering from surgery and several broken bones in my left arm).
My buddies and I turned my SP back over and I repeatedly went up and down that same hill, hitting that same root in 2-wheel with no problems.
Now anyone with any ATV\dirtbike experience knows that you never, ever, use the front brakes going downward. (duh)
The point to this TRUE story is: I'm glad I have my choice of 4x4 or 2x4; (I just need to remember to use it!) It certainly comes in handy.. Some "new buyers" might want to keep this in mind....... Ride-on Polcat

 

POLCAT your lucky you weren't hurt bad.I really don't see how the AWD could have effected ya,don't get me werong I'm not disputing your word.But would be hard to engage AWD without haveing back wheels spinning faster than front.Just because swich says 4 wheel it don't mean you are locked in,it's on demand,please don't take this wrong way,just trying to figure how it happened! CM

 

And how many soldiers were left in the coooler when this happened. Oh none now i see what happened .

 

COB, I'm not gonna get mad at you. I know You've been "flogged" for JUST answering Questions. (I've been reading a few of the posts).
Anyway, getting back to the AWD; I had engaged the 4x4 while going up that hill to find a short-cut. ( A 325mag.4x4 had a flat and I was looking for a better way back to the truck.) Well, I got off my wheeler to ask a fella if he had some air,(nope) turned around (with out thinking)and went right back down the same path I'd went up, front and rear wheels were scooting, I tapped the throttle to loosen the(EBS) brake but it was to late. I got off Scot-free, The SP needs two new racks though. Take care Polcat

 

The same thing happened to me on my CAT. The Cat is in 4wd all the time, so when you gear down the front wheels try to slow you down too.
Anyways, I was riding in West Point, Tn. on March 19, 2000. I was going down a VERY steep hill and geared from 2nd to 1st. Along with the gearing down, I hit an exposed tree root sticking up about 6". With those two combined, the CAT took a nose dive, threw me off, came back down onto me, and flipped one more time, landing right-side-up.
The only injuries that I suffered were a broken Clavicle (bone running from sholder to collar) and being sore the next few days. The CAT 400 4x4 only suffered a badlt bent rear rack (replaced), scratched fenders, bent front bumper and rack (bent back into place), and a missing bright/dim switch. All is fine now.

 

Just so I understand, is the premise:

Descending hills, with engine compression braking, in 2WD is safer than descending in 4WD?

If so, an explanation of the mechanism for this type of "disaster" would be appreciated.

While I previously thought braking, linked uniformly to all four wheels through the drivetrain, was an advantage descending hills in comparison to rear-wheel-only engine compression braking, I don't argue the point.

Instead, I respectfully ask the question: Why is rear-wheel-only engine compression braking superior to 4WD engine compression braking when descending hills?

Best wishes for a full and speedy recovery, polcat2!

Tree Farmer

 

I was using a power line to get back to my truck last week by GPS and had an exciting ride. I tried to lock my SP in 4x4 by backing up with my thumb on the override button. This seemed to really work because when I was going down a really steep part the front wheels would lock up (from the ebs without the brake) and I would loose controll. I then released the override but it seemed to stay engaged. I nearly lost it twice. You have to remember that we don't have a differential action on the front end. I don't ever remember my honda 300 4x4 ever acting like this because (I guess) one wheel could slide at a time. Anyway I beleive it may be for a reason that you can't (or should'nt) put the sp in full time 4x4.

 

I know Polarises have no differentials, Gardnr10; polcat2, in his initial post on this topic, asked about "full-time [4WD] quads with engine braking," excluding Polarises, I think, from that part of his discussion.

I was unaware full-time 4WD quads with engine braking posed greater risks than 2WD quads when descending hills, asking why this is so.

By the way, do Polarises have single-lever braking? Applying braking force to all four wheels simultaneously (and at the same time)? If 4WD engine compression braking is a threat, is not 4-wheel brakes? Just askin'!

Tree Farmer

 

Chickenman,
Sometimes when the AWD engages it engages with so much pressure on the hubs, it does not release easily. Sometimes, you have to put your bike in reverse. I have seen this several times.

Greg

 

I use only the rear Auxiliary (foot brake) when at all possible going down very steep hills. If my Wheeler(rear wheels) gets to sliding too fast; then I can apply the Hand brake(all-wheel braking). To slow it up a bit.
Engine braking is a nice feature, and 99% of the time, it is a great asset, but when descending down very steep stuff, be careful. later Polcat