Mowing Nervous about mowing this hill with my new BX1870

[brasco426]

Lots of great info on this particular thread. That's one of the great things about TBN and the people that contribute to it. The best advice I might be able to give is to start easy by going up and down hills first until you learn what the machine can and can't do. Seat time is the best schooling one can get, just ease into it and don't take on more than your skill set can handle.

 

[dgraves49]

Wondering out loud if you might not have as much clearance as you want if you lower the whole tractor with smaller tires (?) One of my complaints with small Kubotas is that you can't lift the MMM very high to clear things. That's especially a nuisance when doing something besides mowing & sometimes trying to load onto a trailer with a raised threshold. The duals would certainly give you more "anti-tip-over" margin. Of course spacers are made for Kubota wheels to get wider stance in the mid size tractors. Not seen any for the small ones.

My plan is to run the slightly smaller tires on the outside and the stock tires on the inside, so I wouldn't be losing any clearance. That way I would be running on the inside tires most of the time. The smaller outside tires would hit the ground as soon as the machine started to tip.
I can do the duals cheaper than the spacers I have seen. since the set up uses the wheel weight holes to tie them together they wont have to be Kubota wheels. I have found used 12 inch wheels with tires that fit my requirements on craigs list for $50.00 and the adapter set up is just over $50.00.

 

[JWR]

A ha ! Sounds like a plan. I guess you would not want the outer tires to be much smaller diameter since when they touch you would already be tipped over a little bit. Still a neat idea.

 

[Xfaxman]

Since JWR's chart didn't show in post #18, I will post one that shows angles, degrees and ratio:

And side hill mowing the 1/2 ratio, 26.6 degree, 50% slope, back of the dam.

 

[JWR]

Good chart with a little more detail than the one I had. It is always hard to tell from a picture but 2 out of 3 of your pictures don't really seem to be as steep as 50%. A 50% slope is pretty much my limit for mowing with a bush hog unless it is just a short section I can come straight down.

 

[CurtisC]

I'll take issue with this and relate a story that I've written up here several other times.
I had my BX in full loader/weighted/dig mode. FEL on, 275 lb bar on the 3ph, 50 lbs of wheel weights on each rear tire. My rear tires are filled. I drove to my sidehill where I've felt uncomfortable at times. My FEL was about 3 inches off the ground, the weight bar was about axle height. I dismounted, stepped to the rear and pushed on the ROPS from the uphill side. I lifted the rear wheel off the ground with one hand. I then went back to the garage and stripped it down to mowing mode (sans MMM, which would improve the situation even more). I took off the weight bar, wheel weights and FEL, drove back to the exact same spot and conducted the same experiment. I was unable to push the ROPS enough to lift the back wheel at all, certainly not with one hand.

The FEL can be a great emergency brake on a hill. It *might* save you from rolling *if* you got it down quick enough to take the weight off the front axle. But it will also put you a *LONG* ways toward rolling in the first place.



Agree with this 100%. A 15 degree slope will not bother a BX. My hill measures about 23 degrees.

Here's the thing about lateral stability (rollover) - unlike a car or truck, resistance to rollover only comes from the rear axle not the front. The front axle is connected to the frame on a pivot pin offering no resistance to rollover until it has reached its max angle of pivot -usually well after the tractor is on its way over. Keeping the bucket low is a must, taking the FEL off or making other adjustments that lower or move the total CG aft toward a line between the rear tire contact points improves stability. Picture a triangular sided box formed by four points: front axle pivot, rear wheel ground contact points, and location of the total tractor CG with a plumb bob hanging from that CG point. As you lift each corner of the triangular base there's a point where plumb bob swings outside of the box (rollover). As you move the CG forward or higher you don't have to lift the base as far for that to happen. You can see why a fully loaded and raised FEL (maximum height and distance forward for total tractor CG) provides the highest risk of rollover. Putting the bucket on the ground not only lowers the CG but it changes the base from a triangle to rectangle replacing the axle pivot point with the two outer bucket contact points - greatly increasing how far you must raise one side of the base. Low CG just forward of the rear axle provides maximum stability traversing a hill.

 

[RaydaKub]

Here's the thing about lateral stability (rollover) - unlike a car or truck, resistance to rollover only comes from the rear axle not the front. The front axle is connected to the frame on a pivot pin offering no resistance to rollover until it has reached its max angle of pivot -usually well after the tractor is on its way over. Keeping the bucket low is a must, taking the FEL off or making other adjustments that lower or move the total CG aft toward a line between the rear tire contact points improves stability. Picture a triangular sided box formed by four points: front axle pivot, rear wheel ground contact points, and location of the total tractor CG with a plumb bob hanging from that CG point. As you lift each corner of the triangular base there's a point where plumb bob swings outside of the box (rollover). As you move the CG forward or higher you don't have to lift the base as far for that to happen. You can see why a fully loaded and raised FEL (maximum height and distance forward for total tractor CG) provides the highest risk of rollover. Putting the bucket on the ground not only lowers the CG but it changes the base from a triangle to rectangle replacing the axle pivot point with the two outer bucket contact points - greatly increasing how far you must raise one side of the base. Low CG just forward of the rear axle provides maximum stability traversing a hill.

Nicely explained, CurtisC.
Just to poke at a couple of your points:
1) Putting the bucket on the ground lowers CG and changes base to a rectangle.
Both are true, but the base doesn't change until it hits the ground. 1 mm off the ground and you still have the triangle. Once it hits the ground, be aware that it could become a sled and slide down, probably no worse safety-wise than the tip, but could add to the drama. In addition, this relies on the operator to provide it at just the right instant,
I'm not at all sure that a FEL on the ground would cause a lower CG than the bare tractor. Would be an interesting calculation.
2) Low CG just forward of the rear axle provides maximum stability traversing a hill.
And that is something that a FEL will *NEVER* help achieve because it is mostly forward of the front axle, not by the rear.

 

[Xfaxman]

Good chart with a little more detail than the one I had. It is always hard to tell from a picture but 2 out of 3 of your pictures don't really seem to be as steep as 50%. A 50% slope is pretty much my limit for mowing with a bush hog unless it is just a short section I can come straight down.

Yep, that is why I took these pictures in the same area.

The hanging tow rope compensates for any camera lean and shows true straight up and down. The protractor shows 30 degrees of body lean on the 50% slope.

 

[tractorshopper]

This is about the steepest spot I side-hill mow. I need to measure it over the width of the tractor one of these days to accurately report on it. I can still comfortably turn up or down in this spot. While sitting on the tractor, I have stopped in this spot and wiggled my weight back and forth and no wheel leaves the ground, so it could go steeper; I just don't have a steeper spot at the house or the property that I feel uncomfortable on. I don't purposely lean uphill on this slope either. My weight doesn't seem to make a difference.

I have my rear wheels filled and I would never attempt this with the FEL on or any implement on the back. Every time I've come close to rolling a tractor, it's because of the loader or rear implement raising the COG. I've always been able to drop the loader in time luckily so far.

I never took my old lawn tractor side hill in this spot. I never felt comfortable enough on it, so mowed up and down. I also would have never taken my L3800 on this spot either. Just would have felt way too scared to do so.

 

[CurtisC]

Nicely explained, CurtisC.
Just to poke at a couple of your points:
1) Putting the bucket on the ground lowers CG and changes base to a rectangle.
Both are true, but the base doesn't change until it hits the ground. 1 mm off the ground and you still have the triangle. Once it hits the ground, be aware that it could become a sled and slide down, probably no worse safety-wise than the tip, but could add to the drama. In addition, this relies on the operator to provide it at just the right instant,
I'm not at all sure that a FEL on the ground would cause a lower CG than the bare tractor. Would be an interesting calculation.
2) Low CG just forward of the rear axle provides maximum stability traversing a hill.
And that is something that a FEL will *NEVER* help achieve because it is mostly forward of the front axle, not by the rear.

Raydakub,
I agree completely with both of your observations. Meant to say keeping bucket low is a must but taking FEL off was better. I spend a lot of time sideways on a steep driveway spring cleaning the drainage ditches with the B/H extended out behind, low and uphill to bring CG back and "inside the box". My sense is to many folks don't appreciate how fast the handy but front end heavy FEL can get them in trouble.