Hello brycegtx, Now were comparing apples to oranges. The jeeps 4wd is nothing like the polaris 4wd. It uses gearator pumps in the differentials, and on a polaris, there is no differential. When you go around a corner in awd, its actually in 2wd. Just because the switch is in the awd position, doesnt mean its in 4wd. The reason the front tires can spin at different rates, is because the hubs are disengaged.
Ive never had the front jump and slide going around a corner in 4wd...i have both yami and honda. I can even go on dry pavement, in 4wd and it goes just fine. The steering resistance is only slightly higher, but the tires do just fine.

"Seems to me that true 4 wheel drive provides power to any wheel or wheels when any of the others start to slip. "
This is true, but the polaris system is all or nothing, it cant selectivly put power left and right in the front, ...if the hubs are engaged, the two front tires are locked together. It would need a differential in order to transfer power back and forth.

 

I have been reading the post very good answers.
Here is my question on this if you say the front travels 20% or 17% slower so if you could change the ratio you should be able to have it lock in full time when engaged like on a scrambler with the rear chain drive tou should be able to slow the speed of the tires in the back by adding a tooth or two to the rear spocket does this seem right?
Maybe someone can answer this for me

 

Alpine2
Because the front is gear driven, and the back is chain and sproket...it might not be possible to get the ratios exact. They could probably be close, but on the polaris there is no built in slip...no center differential or front and rear differential. This would lead to some binding of the drivetrain if there couldnt be any slip, in awd. Now if it were a pure mud machine, and didnt go in high traction areas, it would work just fine, because the tires would provide the slippage.
Even if you could get the front and rear to the same ratio...the front would still be locked,side to side, whenever its in awd, and steering would be difficult and tire wear would be bad.

 

> Ive never had the front jump and slide going around a corner in 4wd...i have both yami and honda. I can even go on >dry pavement, in 4wd and it goes just fine. The steering resistance is only slightly higher, but the tires do just fine.

Hondabuster,

Correct me if I'm wrong, and no disrespect intended, but from your Bio it looks like the models of Yamaha and Honda you own (Honda Foreman and Yamaha Kodiak) do not have a locking front end (unless the Kodiak is brand new). If they do not a have a locking front end, then they have a front differential, which means two things:

1. They have three wheel drive (instead of four)
2. They will not bind, or "jump" in tight corners on high traction sufaces, because only only one front wheel is being driven at a time. This binding will only happen on a 4wd ATV if it has a locker front end, and is on a high traction surface, with the front end locked.

Take care,
Lorrinl

 

I just don’t get were you are going with this:

The comparison with the automotive differential is nonsense for reasons I won’t go into here.

You do not need all four wheels locked up in unison unless you are going straight ahead and even then it’s difficult to control.
The beauty of the Polaris clutch system is even with the switch on IT IS NOT LOCKED this is an advantage not a shortcoming like some of you have stated!

This system works great in theory and I have plenty of problems with the upkeep on these hubs. But for lightweight applications like ATV’s it is a good system. When you get into specialty applications like mud bogs or rock climbing then lockers may have some advantages. But for 99% of the riders it allows the POTENTIAL of all wheel drive without the shortcoming of wide turning radius and that heavy steering feeling.

 

I agree with ZBart. For true all-terrain, this system is ideal. But if you are just a mud bogger, "tricking" this system or using it how it is may not be the best solution. This system is designed to allow the best traction in most any type of terrain, instantaneously.

I, for one, have had no problems with my hubs. The occaisional jam of one hub, but in thousands of transitions from forward to reverse, this is bound to happen sometimes.

The simplicity of this system makes it useful as well. It is not possible to get more traction than four locked wheels (from a standard four-wheel quad). So competitors' systems may get equal traction, but probably not better. And the Polaris system is probably the easiest to operate, requiring the least input and know-how.

Tyler

 

Your tires do in fact slid when your quad turns a corner. Sometimes it will jump and jerk, sometimes the tires will only slip without you noticing. This happens because you have no center differential in those quads. If you lock the front end it will be even worse. And yes, your stearing will be heavy. The Polaris however, will allow the wheels to free wheel when it goes into a corner, so the steering will not be heavy. Quite frankly, I think the Jeep is quite similar to the Polaris in that the Active four wheel drive system will not start working until the wheels actually slip. The idea of transfering torque on high traction surfaces with a center differential happens when you least need it; on high traction surfaces. So I don't see the big difference or any advantage.
Until you loose traction, I think that it may not matter much where the torque is applied. Particularly on a quad where both rear tires are locked together. Fact is, at all but the lowest acceleration, most torque is applied through the rear wheels on a quad anyways. Unfortuantely, no quad manufacturers are able to selectively apply torque to the front wheels. However, Polaris has the distinction of not forcing the front wheels to be tied to the rear or to each other. This is the closest you will ever find to a center differential on a quad.
Whenever you lock the front and back wheels together as on most 4wd quads, torque actually transfers from the front tires back to the rears when the quad turns the corners (drive line windup). Besides causing the front tires to slid in the corners, it also reverses the torque bias on the front end so the engine is no longer driving the front tires. When you come out of the turn, the rear tires must slip before torque is reapplied to the front tires. The Yamaha and others put a compliant member in the front drive that causes even more driveline windup. So the sublties of what tire slips when becomes even more complicated with non-Polaris systems.
Now the fact is, very few people realize what is happening, they only see a quad that can't make sharp turns or the steering gets heavy, but clearly these points are why that happens.

 

hondabuster
Thanx for the answer to my ? it makes sense for most applications for it to react the way it does I myself have had no problems with the system I was just curious if it could be done on a Scram because of the chain drive

 

Thank you for the clarification, BryceGTX. It irritates me when people do not understand these systems and begin to promote or demote them. If you spend thousands of dollars on a toy, you would think that people would take the time to learn how they work.

But then again, I bet a good chunk of licensed drivers have no idea how an auto transmission works....

 

Hey tyler711. Thanks for the vote of confidence. You made my whole day. [img]i/expressions/face-icon-small-smile.gif[/img]
BryceGTX