Is the rule of thumb, "if you can reverse up the hill, you can drive up the hill"?

rc51stierhoff

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I agree with Grandad…Where the limit is, honestly on a tractor I am not sure and don’t want to find out. I am sure it takes longer to turn my orange turtle right side up than to turn upside down. But from another perspective, in my youth I have done extremely dangerous and incredible things…sometimes on the safer side of a closed course track most times not. Sometimes a danger to only myself, sometimes to with someone on the back (I am talking motorcycles)…anyway there is a balance point whether on the front wheel or the rear…once you past it, the machine is riding you…on front wheel, touching brake will not recover it…rear wheel touching rear brake can bring it down, but usually sort of violent…On the way up (rear wheel), sure you can shift it and you can walk it into triple digits, but that makes the recovery more violent with the rear brake if go past the balance point. Where balance point is on tractor? I am not sure and don’t want to find out, I suspect the brakes on tractor have less touch than on a race machine. (Seeing ground below the machine as you transfer weight to the balance point is misleading….your eyes see ‘on the ground’ not the lack of traction transferring the weight to the other axle.

Side to side…let’s think off road 4x4 travel…generally once the wheel on Left side is above the wheel on R side you are at or approaching the balance limit…width of track and tire size has some impact on COG, but in general one wheel on one side higher than the other side you are near a balance point…tractor is sort of closer to 4x4 vehicle in my perspective than the 2 wheel machines. Off road vehicles also have suspension basically at the hubs (gain traction with some level of suspension compression vs only a center pivot on the front axle like a tractor without suspension.

Just sayin’…keep the rubber side down, and as fast as necessary and as slow as possible. Get a little happy with the throttle and or the machine starts to bounce, I am not sure how you recover a machine starting to slide, maybe sideways and, has a front axle with a center pivot…i did not say it’s impossible, but i would question are we lucky or good. Anyway keep the rubber side down. 🥃
 

troverman

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I mow a few dams. Here's one to give some perspective about a very steep dam with not much room for error. Back up with a flail mower raised; mow down. No loader attached as its too steep to back up with the added weight on the front. In this shot I'm doing it with an MX4800 but I have done it with the little B2920 at the bottom as well. Keep your tractor perpendicular to the top of the slope. If it starts to slide, be prepared to change directions to forward (downhill) immediately. Do not allow the tractor to get sideways at all, or you might die. Different grasses offer different levels of traction. Ferns are very slippery. Beware of morning and evening dew. The first time or two will stress you right out. I've done this property 7 years now, and I'm not bothered basically at all anymore. This is steep enough to where driving up would not be possible.
IMG_4507.jpeg
 
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troverman

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Completely aside from the safety considerations discussed so far here, folks need to recognize the potential consequences to engine and hydraulics of operating on extreme slopes. These tractors typically have pickup systems in the oil pan and also in the transmission to supply oil/hydraulic fluid. There will be some slope and orientation where those pickups may no longer draw fluid, potentially leading to starvation in the engine and/or hydraulics. Lack of engine lubrication is bad enough to consider; when the HST no longer has fluid, there is the potential for loss of traction and freewheeling.

I don't know what the operating limits are for these tractors, but I would not assume they are designed to safely operate on a 60 deg. slope or anything close.
I've very steep slope work for a municipality for 7 years now, dams, reservoirs, and heavily sloped capped landfills. I've run nothing but Kubotas - A B series, three different L series, and two MX series. You can't really go larger than an MX due to size and weight constraints based upon the job. I've put hundreds of hours on these machines and never had issues with the performance of the engine or hydraulic systems. All of my machines have been hydrostatic except one was a Glideshift. There are lots of reports of HST machines not being able to withstand repeated hard use in hot weather. I mow in 90 degree weather up and down hillsides all day long...transmissions have been fine. These are great machines, reliable workhorses.
 

pokey1416

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Wow! That is one scary slope. And I thought this dune hill at Silver Lake State Park in my truck was crazy. Goes to show you “one man’s comfort is another’s crisis”

A60309FA-A3A6-4EE3-83C8-A4BD36536543.jpeg
 
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Grandad4

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Apr 5, 2016
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I've very steep slope work for a municipality for 7 years now, dams, reservoirs, and heavily sloped capped landfills. I've run nothing but Kubotas - A B series, three different L series, and two MX series. You can't really go larger than an MX due to size and weight constraints based upon the job. I've put hundreds of hours on these machines and never had issues with the performance of the engine or hydraulic systems. All of my machines have been hydrostatic except one was a Glideshift. There are lots of reports of HST machines not being able to withstand repeated hard use in hot weather. I mow in 90 degree weather up and down hillsides all day long...transmissions have been fine. These are great machines, reliable workhorses.
I've very steep slope work for a municipality for 7 years now, dams, reservoirs, and heavily sloped capped landfills. I've run nothing but Kubotas - A B series, three different L series, and two MX series. You can't really go larger than an MX due to size and weight constraints based upon the job. I've put hundreds of hours on these machines and never had issues with the performance of the engine or hydraulic systems. All of my machines have been hydrostatic except one was a Glideshift. There are lots of reports of HST machines not being able to withstand repeated hard use in hot weather. I mow in 90 degree weather up and down hillsides all day long...transmissions have been fine. These are great machines, reliable workhorses.
Totally agree with that. You can safely work on grades if you are careful and stay within the limits of the equipment. But there is a limit to what is safe with every piece of machinery, considering how it is designed and the laws of gravity.
Years ago I tried to help a guy (remotely), who had taken his new Grand L several miles into a hilly West Viginia trail and couldn't get it back out. He evidently had the tractor at such a steep angle that the HST would not function because it was not getting fluid.
 

troverman

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Thanks! I'm liking it so far.
 

Henro

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For posterity, if anyone views this thread in the future, a visual look at degrees and percent slope.

1BAA3AF5-4114-4256-9139-9B7C5EF2FFAB.jpeg
 
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BigG

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For posterity, if anyone views this thread in the future, a visual look at degrees and percent slope.

View attachment 81920
Could you explain where these numbers come from? 5.71 degrees is 10% of what? 45 degrees is 100% of what? I am not saying this is wrong rather, how did they come up with the numbers?
 

bird dogger

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Could you explain where these numbers come from? 5.71 degrees is 10% of what? 45 degrees is 100% of what? I am not saying this is wrong rather, how did they come up with the numbers?
Perceent of slope is the vertical rise divided by the horizontal run x 100. Thus, 1' rise in 10' horizontal run = 1/10 x100 or 10%
The angle comes from simple trig function: opposite side / adjacent side (of a right triangle) = tangent of .1 which is 5.71 degrees (where opposite side is the height and adjacent side is the run of the right triangle.

In a 100 % slope: 100 ft run with 100 ft rise.......100/100 x 100 = 100% slope
The angle: opposite over adjacent.......100/100 = an angle with a tangent of 1 which is 45 degrees.
 
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jyoutz

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I mow 40-60% slopes on my hilly property and that’s steep enough. I couldn’t imagine trying much steeper than that.

Mike
40-60% is pretty steep, unless the slopes are short
 
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bcp

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Don't try mowing forwards or backwards, up or down a 60 degree hill. :)
60-degree-angle-triangle.jpg



When you measure straight down from the end of a level 8ft board (about 100 inches), the inch measurement will (about) equal the grade percent. "About" is good enough since your slope is not perfectly angled anyway.

Bruce
 
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DaveFromMi

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When I was a teenager, I had a pretty bad-a** Yamaha Enduro 125. It had dual sport tire tread, more towards the dirt. It would go up a dry/rocky 45° hill, with a driver and passenger. At that point, we leaned forward on bike as much as possible; the danger being the front tire coming off the ground.
Other similar bikes had front ends that were too light to make it up the grade.