Too low of gear choice !!

TonyV · Jul 22, 2005

Eric, I'm not sure that the dynamics of a soap box derby style vehicle is germane to tractor dynamics. Since a soap box derby car is relatively symetrical from front to rear, from side to side and top to bottom, the moment of inertia is also centered, also the 4 tires are the same. With most tractors, the moment of inertia is going to be quite different, and impossible to generalize on. If my tires are loaded, for instance, then the moment of inertia is skewed to the rear, or if there is a FEL, without any substantial rear loading, then we're skewed to the front. In any event, I don't believe that you can make an adequate generalized prediction on sway characteristics in slippery conditions without analyzing the individual tractor, since there are a number of variables involved. I suppose this is why intuition prevails in the circumatances. Intuition tells me that 4WD is better than 2WD, and that if I have a differential lock, then use it. Intuition also tells me that even in 4 wheel drive, my rear tires are likely to grab better than my front. What this means exactly if I'm sliding down a hill wondering if I'll get a chance to change my shorts, I'm not sure. /forums/images/graemlins/shocked.gif I'm thinking though, If one were to anicipate these operating conditions, to at least unlatch the brake pedals (on newer models) so that individual rear wheel braking can be used to help keep the tractor under control in the event of a skid. Heres hoping I never really have to find out. /forums/images/graemlins/smirk.gif

...Tony

woodlot · Jul 22, 2005

Many moons ago I had a Jeep that would sometimes lock-up the rear wheels when braking. Wow, was that ever a wild, scary ride. I can tell you directly that your soap box tests hold true in a Jeep!

California · Jul 22, 2005

Another emergency response to a downhill slide might be to raise the mower, which will load more weight on the rear tires.

ChuckT · Jul 22, 2005

And you're sure that a Yanmar 2000 has brakes on all four wheels?
cvt

JerryG · Jul 22, 2005

where if you lock up all four, than its just like a sled down the hill, but pointing the right direction. 
Exactly or a lot better chance from my experience.

Soundguy · Jul 28, 2005

( And you're sure that a Yanmar 2000 has brakes on all four wheels )

Yanies will have brakes on the rear. if it is a 4wd version (denoted with a 'D' ) you might get some braking action thru the drivetrain rear to front.. etc..

Soundguy

SteveInMD · Jul 29, 2005

Wouldn't backing down the hill be a good choice? It would put more weight on the rear wheels.

slowrev · Aug 1, 2005

Backing down a hill "can" be very dangerous, hitting the brakes while backing down a hill can cause the tractor to flip back on you very rapidly! It is mush less likely to flip oner it's "nose" going down the hill forward.
Ben

BXRICK · Aug 1, 2005

My parents' house (the one I grew up in) was on a very steep hill with a driveway that was a challenge in the winter. After I learned to drive, I learned that in my 4WD trucks, the best bet was to pick a low gear, and use some throttle to keep things under control on the ice.
Inching down on the brakes only worked until a wheel broke loose and started sliding. Then you just hung on for the ride.

In general use whatever gear it takes to keep the wheels rolling (as opposed to sliding). By using a slightly low gear and then adding some throttle, you can slow things down a bit by letting off the throttle.

This same idea seems to work for me with my tractor on, for instance, wet grass while heading downhill. Though it works much better in 4WD than with just the rear wheels.

Boomerang1 · Aug 1, 2005

A sliding tire travels faster than a rolling tire. Lock up the wheels on a trailer when you are on ice and it will try to pass you. I grew up in the midwest driving trucks with trailers and have seen many accidents because of this. If you lock up all four wheels on a car while driving on ice or a slippery road, it will actually pick up speed.