Mower defies logic

Discussion in 'Lawn Mowing' started by Envy Lawn Service, Oct 28, 2005.

  1. Envy Lawn Service

    Envy Lawn Service LawnSite Fanatic
    Posts: 11,062

    OK, this is my first non-health issue related post in a while. But I happened to figure this out by accident due to the fact of all I've had going on lately. Here's the deal...

    The Lesco has a dual mode front axle. With the use of 2 quick pins, you can set it to pivot or set it to fixed/rigid. I for one LIKE this option and put it to use. In general, I run it in the fixed position because that is what I have became acustomed to using other rigid frame ZTR's. But I do like to switch over to pivoting on some sites, if for no other reason than to have the blades actually cut the grass once in a while in places where otherwise it tends to ride up and over the grass.

    Anyways, I had it set to pivot at one point before everything happened. I left it that way after that job and forgot it was set that way. So when I resumed and rolled off on the first job I had forgotten it was set that way. I said what the heck and left it that way because I didn't want to stop on a level place or drive back on the trailer to set it to fixed.

    This was one of the rougher and steeper properties that I wouldn't generally dare just select the pivot setting. So what I ended up finding out actually defies logic of what is 'generally accepted' as truth.

    What I found out was that the mower still seems to hold the slopes just as well as it ever did. I judge that from having it on some really steep slopes, but not the absolute steepest I have.

    In addition, what I found out over the course of an entire day was that the mower actually handles the steep rough places and off-cambers better with the axle set to pivot. That I had expected, but not to the degree of slope angle I was dealing with.

    I even cut some places in ways that I had learned not to cut them in certain conditions in order to avoid slipping. It was like right when the "pucker factor" was the highest, it rolled right on without event and without the slightest sign of slippage.

    The other part that defies logic is that most would think the mower would ride better this way. Well it does to an extent and you can tell it is noticable much easier on the mower to cross rough rolling terrain. But I actually wouldn't define the ride quality as better overall.

    This is because the ride is less rough in the area of up and down, back and forth bucking and choppyness. But at the same time the ride is more rough in the area of a lot more rocking back and forth side to side.

    It's not near as rough in that respect or near the beater that the 52" Lazer HP is. So it's not an exhausting rocking and bucking ride with sharp jolts... Just a lot more movement and rocking side to side that I did not expect.

    Anyways, I just thought all this was a bit interesting.
    And in addition, I do not think this is just limited to my Lesco either.
    As I remember, Country Clipper faired just as well with it's articulating axle and deck.
     
  2. steve45

    steve45 LawnSite Bronze Member
    Posts: 1,325

    With the axle set to pivot, all 4 wheels are on the ground, even in rough terrain. I would think it should hold better on slopes when in pivot mode.
     
  3. Envy Lawn Service

    Envy Lawn Service LawnSite Fanatic
    Posts: 11,062

    Yes, and this I expected in rougher terrain on more moderate slopes.
    But this is NOT generally accepted logic.

    The truth that has been accepted is that a rigid frame is more stable on slopes. To be honest, I also figured rigid would be better for side hilling at all times except when the upper front tire encounters a hump it has to cross. This is in fact where the pivoting axle does shine as I expected. Since there is no lift or wedging occuring, the rear tires can maintain better traction.

    Where I really thought the pivoting axle would cut performance was crossing really steep slopes, while coming down slopes at a diagonal angle, or coming down a slope that is also slanted to the right or left while going down.

    Actually though, what I have found is that the rigid/fixed position must be part of the cause of some problems. It seems that they actually really struggle on humps, bumps and often slip right at the point where they encounter the transition... if you understand what I'm saying....

    Anyways, these are the spots where the operator has learned to pucker up, but it seems the pivoting axle allows the mower to roll right on through these spots with less struggle.
     
  4. mowtech

    mowtech LawnSite Senior Member
    Posts: 252

    Steve45 is correct in that all four wheels are on the ground. The pivoting front axle turns the machine into a "three legged stool." Two legs at the drive tires and the third at the pivot. With a three legged stool all three legs bear the same amount of weight. With a four legged stool one leg is always off the ground and the stool rocks (unless the ground happens to be perfectly flat). With a Z mower control is dependent on traction. If one of the drive wheels is the fourth leg of a stool with no weight on it, you can loose traction and hence control. That's the theory anyway. Now as you say, general belief is that a rigid frame is more stable on slopes. This is true as a pivoting axle moves the pivot point closer to the center of gravity, hence the machine will tip at lower angle. But Z mowers are generally very stable regardless with tip angles well above 45 degrees. What you are really describing is loss of control not stability. These are two different things. So a pivoting axle should be better for controllability on slopes--three legged stool--while a rigid frame should be better for stability. Now when I have been involved with test comparisons between different mowers--pivoting axles versus rigid frames this difference, in controllability, has been deemed insignificant. But this could have been related to other differences such as tire treads, center of gravity, tread width, etc. Your observations on the other hand with the same machine in both modes is compelling proof that there is truly a significant difference per theory. This is very interesting.

    Just an FYI. Generally the reason for pivoting front axles versus rigid frames is ground following. Some believe the pivoting front axle is better as it allows the deck to follow undulations better with less scalping. The down side of this is that the deck can follow too close with every hole that the caster drops into creating an uneven cut. A rigid frame tends not to drop in such holes. The ideal cutting system would be one that responds well to larger undulations yet does not react to the smaller irregularities in the surface.
     
  5. LwnmwrMan22

    LwnmwrMan22 LawnSite Platinum Member
    Posts: 4,372

    The Kubotas have a pivoting front axle.

    I too agree about the ride. It's not as smooth as my four wheel IS Ferris, but it's better than a rigid frame, since you're not getting all the chop chop chop from the front wheels.

    What's also surprising, is that the deck does not scalp on the downhill side.
     
  6. Envy Lawn Service

    Envy Lawn Service LawnSite Fanatic
    Posts: 11,062

    Yeah, but I do get a little tired of the extra side to side rocking though.
    But who's complaining since it takes only seconds to switch back.
    I like having both options.

    As for the deck, no it doesn't scalp on the downhill side. That's because the deck always remains on the same plane as the rear wheels. So if one rear wheel drops in a dip you are more likely to get a scalp or a gap, just as you would if you were driving over a hump on one side.

    I really surprisingly haven't had much issue with scalping or gapping with this machine set either way. The only thing I have to watch is turning into a steep slope face with it set to pivot. The anti-scalp wheels can take some nice divots.
     
  7. logan

    logan LawnSite Senior Member
    from FL
    Posts: 315

    I demo'ed an everride with the pivoting front axle and I loved it. I think it is the next generation on all mowers.
     
  8. Envy Lawn Service

    Envy Lawn Service LawnSite Fanatic
    Posts: 11,062

    Yeah, Country Clipper and Everride have one more additional feature on there mowers that is an advantage in many areas. If you paid close attention, you saw that the deck is hung from the pivoting front axle. So the deck on these machines also pivots/articulates with the front axle, which allows it to better follow ground contours in many conditions.

    After trying all three styles... rigid, pivoting axle and pivoting axle-n-deck...

    What I have realized is that the pivoting can be an advantage for the mower, and as far as the cutting charateristics.... I have realized all three have there good and bad points.... meaning if you encounter enough different terrain conditions you will find good and bad points about all three setups.
     
  9. Envy Lawn Service

    Envy Lawn Service LawnSite Fanatic
    Posts: 11,062

    mowtech,

    VERY GOOD POST!
     
  10. LwnmwrMan22

    LwnmwrMan22 LawnSite Platinum Member
    Posts: 4,372

    Envy -

    I forget, have you ever tried one of Ferris' 4 wheel Independent Suspension machines??

    If you totally want to get rid of the bumps and pretty much just "roll" over the ground, you've got to try one.

    I used to have two, but was disgusted about how they cut in wet grass.
     

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