Wheel spacers or weights for slopes?

[rbtjr]

Just saw this thread. I am very interested in the subject. We also have a L3800HST 4WD, but we have R4 tires, and the R4 wheels on a L3800 can't be adjusted for width. We previously had a M5700. When we first got the L3800, it was very unstable compared to its predecessor. Our rear tires are loaded but our front tires are not. We put 4" spacers on each rear wheel, and it made a lot of difference. Our dealer said that he had never seen or heard of anyone having problems as a result of adding rear wheel spacers. My only thought on wheel spacers for a L3800 is that more width would have been better but for us would have caused issues with getting the tractor placed properly on our trailer (the wheels would have been wider than the inside width of the trailer fenders--and yes, I know that I could have backed the tractor on the trailer, but I couldn't always do that with the assortment of attachments we might have on the tractor).

Even after almost two years I am still getting used to the L3800, so I don't have a definitive answer for the OP or anyone else about the degree of slope that I think I can mow safely. I mow with the FEL on but very low to the ground. I do know that I mow some slopes that are 15% or more without a lot of discomfort, but I mow slowly and am very careful about watching for rocks and such on the high side and holes or depressions on the low side. We have some slopes we mow that look similar to those in the pics posted by the OP. If I am judging the slope in those pics correctly, I mow equivalent slopes with a zero-turn 66" mower, which has a much, much lower center of gravity than the L3800. We have a pond that we mow around. I mow the bottom of the steep slopes on the pond dam and steep sides around the pond with a bush hog by backing the tractor down the slope to the water. It is pretty tedious but it works well and is safe if you stay on high alert about not mistaking reverse for forward when you are close to the water.

 

[Brown Dog]

Just saw this thread... We also have a L3800HST 4WD, but we have R4 tires, and the R4 wheels on a L3800 can't be adjusted for width ...

Can u swap sides with your tire / wheel ?

I swapped left front ovr to the right front & vise versa - keepin the tires turning the same direction.

My JD rim centers were offset & made a needed wider stance.

 

[rbtjr]

No, we can't swap the rear wheels with the R4 tires. The rear wheels on the L3800 that have R1 tires can be changed around. They have different wheel rims. When we bought the L3800, I saw that the next size up in the Kubota L series had rear wheels that could be adjusted even with the R4 tires, but not the L3800. Our M5700 had several positions the rear wheels could be adjusted to. We had them all the way out to provide maximum stability. The L3800 felt very unstable in comparison, which is why I started investigating wheel spacers.

 

[Cord]

If all else fails, resort to a good wide front mount mower with 4 WD like the Kubota's or Toro's to mow those hills.

Gotta be honest, it's not in those mowers either. I've got a 328 with 4wd and the front tires are flipped around for a wider stance. This thing will crab pretty good on a 25 degree slope. I'm not sure how steep it was, but I got myself into a real pickle the other day. I was trying to mow above a retaining wall and approached it from the opposite direction than I usually do. There is a short segment where the grade really pitches down towards the wall. That darn mower was moving forward, but it was crabbing so bad that I was getting too close to the wall. Because of the crab, I couldn't turn up hill without the back tires going over either. I ended up punching the uphill wheel brake and that was enough to get the machine out of the spot. Even then, I've already had 3-4 incidents where I lost traction and the machine slide or didn't react the way I wanted. Buried the mower deck under a massive rose in the front yard once. Thankfully it was a front deck and I didn't get tangled in the thorns. I think part of the problem is the 4wd clutch. It just takes too long for 4wd to engage. When I get a chance, I'll convert the machine over to full time 4wd.

If I had to do it all over, I'd go with the Toro 3500 or Deere 7400. Those machines are factory rated for 25 degree slopes. But look at the width vs height of them. Big difference.

 

[Loadstar]

I put the spread on mine. Just need some Massey suitcases.

 

[vtsnowedin]

Greetings Vtsnow, turf issues might not be your concern, but they were for number9's point of view as he stated . . plus if you are ripping turf you are losing the traction stability beneath you. And certainly traction is all of our concerns and tire profile of an ag tire vs turf tire on a sidehill advantages the turf tire for roll over concerns (side hill).

But for all the science type of center of gravity ( COG) physics . . . I had mentioned when a unit adds either front torsion leverage or rear torsion deflection . . COG is also only part of the story. Often times in our battles to defeat gravity on tractors or motorcycles or atv or bicycles for that matter . . forward momentum (or inertia) helps keep people upright . . . And the loss of that inertia or a forced slowdown of that inertia hurts your "staying upright". A fel on a sidehill or a brush hog behind on a sidehill causes drag on inertia and torsion twist because of gravity. Those implements are at the influence of gravity . . and they are being "pulled down" while we are trying to go sideways on hills.

A mid mount mower or a "direct side" batwing can aid in keeping you upright on a sidehill . . but a fel or trailer/3 pt attachment is never your sidehill friend in the effort at staying upright. You might stay upright in spite of them . . but not because of them.

Those who say COG is the only thing that keeps you upright have apparently never seen a motorcycle race or driven a motorcycle where COG is regularly and continually defeated by "a controlled" momentum or forward inertia . . and the rider continues upright while their COG is far outside their wheels.

Would you put out some examples with the math to demonstrate your point?
Tractors are not motor cycles and when driven by intelligent operators never experience G forces sufficient to cause roll overs. ( YES I know idiots roll them doing J turns on highways on a regular basis.
But to determine the maximum slope a tractor can work on safely you have to assume a prudent slow speed. Cowboys can roll anything on a flat parking lot given enough horse power and speed but if you want to get the weeds mowed on a steep slope you need a setup that is stable in parked position and not needing forward momentum to keep it from rolling over.

 

[AxleHub]

Would you put out some examples with the math to demonstrate your point?
Tractors are not motor cycles and when driven by intelligent operators never experience G forces sufficient to cause roll overs. ( YES I know idiots roll them doing J turns on highways on a regular basis.
But to determine the maximum slope a tractor can work on safely you have to assume a prudent slow speed. Cowboys can roll anything on a flat parking lot given enough horse power and speed but if you want to get the weeds mowed on a steep slope you need a setup that is stable in parked position and not needing forward momentum to keep it from rolling over.

Examples "with the math" is am interesting response. When center of gravity is calculated in a vacuum of any other issues except gravity . . you can have a pure geometric relationship. but when you add in centrifical force . . then center of gravity takes on a different relstionship. "Speed " in your post assumes fast . . while speed in my post assumes movement. So here's an example many people can identify with. Take an 800 pound motorcycle and a 200 pound driver and try to keep it upright (and not feet/foot on the ground . . going 1/2 mile per hour - Virtually no one can do it by "balancing". But let the driver go 2 miles per hour and most bikers can keep it upright. Its because motion helps stabilize gravity's pull to some extent.

Just today I was cutting a sidehill in a downward direction (compound angle). With 3 mph speed . . The focus is on continueing the movement direction. If I'd be going only 1 mph gravity effect on the sidehill takes over. Similarly had I gone up the incline while sidehilling . . Gravity intensifies the battle and wins because momentum is slowed to meaningless gain.

"G forces" is not an equal to forward momentum in the gravity issues . . unless you want to refer to a fraction of g force.

Similarly . . in that same sidehill example . . in that very same location going the same speed . . if I had a fel on the front or pulling a trailer on the back . . I could never maintain a straght line of direction and also stay upright. Why? Because gravity's pull overcomes direction momentum when there is a drag on that momentum.

This also is exactly why a big bump or hole can play heck with sidejill movement . . because it alters forward momentum.

 

[dragoneggs]

Examples "with the math" is am interesting response. When center of gravity is calculated in a vacuum of any other issues except gravity . . you can have a pure geometric relationship. but when you add in centrifical force . . then center of gravity takes on a different relstionship. "Speed " in your post assumes fast . . while speed in my post assumes movement. So here's an example many people can identify with. Take an 800 pound motorcycle and a 200 pound driver and try to keep it upright (and not feet/foot on the ground . . going 1/2 mile per hour - Virtually no one can do it by "balancing". But let the driver go 2 miles per hour and most bikers can keep it upright. Its because motion helps stabilize gravity's pull to some extent.

Just today I was cutting a sidehill in a downward direction (compound angle). With 3 mph speed . . The focus is on continueing the movement direction. If I'd be going only 1 mph gravity effect on the sidehill takes over. Similarly had I gone up the incline while sidehilling . . Gravity intensifies the battle and wins because momentum is slowed to meaningless gain.

"G forces" is not an equal to forward momentum in the gravity issues . . unless you want to refer to a fraction of g force.

Similarly . . in that same sidehill example . . in that very same location going the same speed . . if I had a fel on the front or pulling a trailer on the back . . I could never maintain a straght line of direction and also stay upright. Why? Because gravity's pull overcomes direction momentum when there is a drag on that momentum.

This also is exactly why a big bump or hole can play heck with sidejill movement . . because it alters forward momentum.

AxleHub, while I am with you in spirit... I am having a hard time believing that the slow speeds we are talking about while mowing are going to significantly affect (counteract) the effect of gravity. Your argument while theoretically correct is not realistic for the case at hand in my opinion. The math can be done but your motorcycle analogy is flawed. The rider leaning over to the side is 'fighting' angular momentum not linear momentum. I don't care how fast you are going in a straight line, you can't 'lean' over such that the C of G of the combined weight of you and the vehicle are outside the footprint for long and remain upright... I take that back, you could be flying.

 

[vtsnowedin]

I wouldn't ever want to be in a position or on a slope where I could not come to a stop or change directions without tipping over.

 

[IslandTractor]

Those who say COG is the only thing that keeps you upright have apparently never seen a motorcycle race or driven a motorcycle where COG is regularly and continually defeated by "a controlled" momentum or forward inertia . . and the rider continues upright while their COG is far outside their wheels.

Try leaning a motorcycle over to turn while traveling under 5 mph and let us know how much dynamic stability you experience.

Tractors at typical hillside mowing speed depend primarily on COG. The only significant "dynamic" forces of importance are bumps and holes that raise uphill or downhill wheels suddenly.