Wheel spacers or weights for slopes?

[Poopdeck Pappy]

... I don't know if the highway mowers are low C-G outfitted, but I do know that their operators come with a much larger set of balls than I have! Those guys deserve a lot of respect.

You got THAT right! Those guys have some stones, for sure.

 

[SPYDERLK]

I have been told that tractors with low center of gravity can be ordered. In fact, I did price out a New Holland outfitted that way... I don't know if the highway mowers are low C-G outfitted, but I do know that their operators come with a much larger set of balls than I have! Those guys deserve a lot of respect.

Unfortunately that raises the CG.

 

[number9L]

Mowed the grass today. Just same areas I have been, not the newly worked areas, still fighting trying to get it covered in grass before time runs out. Anyway, ground was a little damp but the weights did make a noticeable difference. Tractor didn't feel as tippy in places it had before. Rear end felt more planted but it did crab a bit, but the ground was damp so to be expected. It crabbed pretty good on the worst spot, I watched the incline-o-meter close and it's a solid 25*.

I don't know for sure but I think there are areas on the newly worked hill that are steeper than that. It's hard to tell just eye balling it, some angles it looks much steeper but others it doesn't look so bad. Guess I'll probably have to wait until spring to find out so I don't get on it and mess up what new grass is starting to grow on it.

I've been reading up on the MF 35 Turf Special and Ford LCG tractors. They are out there on craigslist and other places but most don't have a ROPS and I wouldn't own a tractor without one, especially a tractor that would be used exclusively for slopes. I don't know if I could get used to no HST either *if* I did end up getting serious about getting one. They sure do look like they'd handle slopes good though.

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[TomSeller]

I've been reading up on the MF 35 Turf Special and Ford LCG tractors. They are out there on craigslist and other places but most don't have a ROPS and I wouldn't own a tractor without one, especially a tractor that would be used exclusively for slopes. I don't know if I could get used to no HST either *if* I did end up getting serious about getting one. They sure do look like they'd handle slopes good though.
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They are wide and aftermarket ROPS are available. My MF Turf Special is 96" wide outside edge of rear tire to outside edge. However, 2WD only. I'd say you should see how your spacers work out for you. I have one dedicated to mowing and spraying so it gets its 100 or so hours a year to keep in working condition. Well worth it to me.

 

[skyhook]

Unless you add/delete or relocate weight on the object, the location of the object's C.G. is at a fixed location no matter how the object is rotated.

Liquid loading the tires will lower the C.G. more than the equivalent wheel weight centered on the axle.

Like I said, on a slope, the C of G is changed, it's obvious that the weight is "relocated".

 

[the8080]

The CG is not changed. The side-to-side CG of a tractor is typically under the seat on the center line. As the tractor tips on a slope the CG moves relative (closer) to the downhill rear tire contact patch. The more the tractor tips, the closer the CG is to being over the contact patch. Once the CG is outside (downhill from) the contact patch, the tractor will tip over. The weight of the tractor moves relative to the downhill wheel tire patch but the center of weight of the tractor, CG, doesn't move around on the tractor.

 

[the8080]

An attempt to answer the OPs original question. I am interested in this because a lot of my mowing is on 20 deg slopes and some of it more than that. I am looking at new tractors and trying to decide what configuration will do this as well as my old Ford 3600.

With some very simple assumptions and some very rusty physics I have these answers. Assumptions: L3800 with 60 % of weight on rear axle, 500 lb per rear wheel in ballast. I am calculating stability which I will say is the resistance of the tractor to tip more, no matter the angle. 200 lb rear wheel weight - 15 percent increase in stability. 2 inch additional wheel spacer - 7 percent increase in stability. Both - 22 percent increase in stability.

We need someone in high school that can do this math.

 

[number9L]

Very interesting 8080.....where did you get the 60% weight on rear at? Not contesting it, just wondering the source as I have no idea.

Spacers came today, just got them on a bit ago. Man they look big. It's 72" from outside edge of tread (not sidewall).

Also, I bought a set of steel exercise weights for a project early in the year and have had a lot of them sitting around with no use. I got to thinking about weight down low on the tractor and what I could do with those to aid in that. I rarely use the drawbar on my tractor, so I used two 6" bolts I had laying around and bolted several of those weights to both ends of the drawbar hanging under the tractor. It lowered my ground clearance about 2" but added another 130# under the rear axle. May not help much but every little bit adds up. If I find the reduction in ground clearance an issue I'll pull them back off.

I'll post some pics when I get them off my phone.

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[number9L]

Something else in response to 8080's post....

My rear tires are 11.2-24 R1's and filled with washer fluid, which according to charts at a 75% fill is only 200# each. I noticed tonight when I removed the tires to swap the spacers, that at least one tire "sounded" from the sloshing inside that it wasn't filled to 75% (or top of wheel). Now I am questioning in my mind if the dealer really filled them to that level. I am going to check that tomorrow of I get time.

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[skyhook]

Perhaps I'm not explaining myself correctly...

The tractor on the left, has a wider wheel stance,, notice where the CG has shifted.