Gravely ZTR questions on stability and driving style

[OKnewguy]

Hey guys, I mow about 2.5 to 3 acres and my cheap bolens (lowes special) had become very expensive to keep going. So I started to look for used ztr's. I really liked the pro grade machines but bought this little Gravely. It is a 1742 zt and seems well built. It mows well, but is VERY unstable on the slightest slop. Is this indicative of this mower or are the tires excesivly worn? Would loading the tires work? Right now this mower is basically unusable. The attached pics might help to show the shape of the tires. Any suggestion would be greatly appreciated.
Dave

 

[jcmseven]

I really like the Gravely commercial ZTR's but the little one's for homeowners are a bit unstable. They are nice, though, but I personally do not think it is the tires.

John M

 

[OKnewguy]

Thanks for your reply. So this might be a characteristic of this model. I currently have it for sale, hopefully I can get it turned around. Are most ztr's going to be considerably more stable then this one? For example, in the attached pic I would normally stradle the drive with my left wheels and the grass on my right wheels, but with the ztr, it could not do this, it just kept plunking down on the drive. You might even see a little bit of skid mark in the grass were it left a line in the grass, from me trying to keep it turning right.
Thanks
Dave

 

[jcmseven]

I think that the characteristics you describe would be present in almost any small-tired homeowner level machine. The little Gravely you have is no different in this way from any other brand of this size--it is a problem inherant to the machines. One thing you could do if traction is an issue is to try loading the rear tires, or going with a slightly more-aggressive pattern in tread. These small tires come in many patterns and could be changed to a bar type or HPAP type tire cheaply. Then you could load them and see if that makes any difference. It probably would, and that way you would not necessarily have to rid yourself of a mower you otherwise find acceptable. Sure does beat stepping up to a larger and more-expensive machine, and if it does not help, you would still not be out that much in dollars. These rear tires will not hold that much fluid and I doubt would place significantly more strain on the wheel motors--which must also be considered. ZTR's are great, but no matter what size, they all have some issues with stability in certain circumstances. I thought my dad's 757 was the most stable machine I had ever used, until I helped my neighbor on his 10 acre plot mow one week he was away. After sliding sideways down a 75' slope, I changed my mind quickly. So you are not alone in your plight.

John M

 

[OKnewguy]

Thanks for the reply, I am currently trying to sell it, and hopefully can get this little experiment out of the way for not much money. I guess it takes a big heavy comercial grade ztr to get away from these unfortunate characteristics.
Thanks, Dave

 

[CurtC]

Thanks for the reply, I am currently trying to sell it, and hopefully can get this little experiment out of the way for not much money. I guess it takes a big heavy comercial grade ztr to get away from these unfortunate characteristics.
Thanks, Dave

Just a data point, I have a full size Gravely ZTR 60, the commercial version, I mow on some pretty steep slopes and don't have any significant trouble.

 

[xPosTech]

It seems to me that technique is the main problem people have with ZTRs. You say the right tire was leaving skid marks when you were trying to bear right straddling the driveway/grass line. I don't know what "plunking down" is, but a rearward touch of the right stick or a forward touch of the left would bear the mower to the right.

Either or both sticks can steer. Novice operators usually have better luck holding one stick stationary and steering with the other. Once that is mastered, reverse the stationary/steering sticks. When you are comfortable steering with either start using both. I use my armrests and actually operate with forefingers and thumbs, unless I'm maneuvering around trees, brush etc.

The secret to traversing slopes is to establish a speed and hold the uphill side stick stationary. It has much less traction than the downhill side, where the weight has transfered. Attempting to control the mower with the uphill side will almost always break traction. Sometimes you can recover when you break traction, sometimes not.

Trying to mow at too slow a speed on a slope will get the mower squirrelly, too, because the swiveling front end wants to drift downhill. Sorta like riding a bicycle across a slope.

It takes a while to become proficient on one. If you have any doubts at all don't take a ZTR on a slope. Especially if you can't go in a straight or curving line on level ground. Sell it and try one of the Cub "i" series. They are almost as fast as a 'conventional' ZTR.

These are just my experiences on my ZTR. Don't try this at home, and all the other lawyer type stuff.

Ted

 

[OKnewguy]

On this paticular area, I was trying to mow along the drive or traversing the very small angle. I tried it numerous times, full left throttle, sitting still and giving full left and reverse right, you name it. My right drive wheel (on the high side) just did not have enought traction to do anything. So this leaves appling the left thottle which would drag the right side. Even doing this, it could not go up the slight inline or even continue to go straigt. This drive is 10' from the property line and would be impractical to try to mow going up and down. My neigbor just got a sweet Ferris ztr, that thing can take any angle we have on our properties. There is no way this is all due to in-experience, I do realize that a ztr is going to have a learning curve, but the only way I can get it to go up this slight incline is straight up or down.
Thanks, Dave

 

[Freds]

I can't help you with the Gravely, but when I bought my ZTR (three mows ago) the dealer told me they can be tricky to master on a slope, that they keep wanting to turn downhill. He was right, but I wouldn't say I feel unstable. My slope is probably 30 degrees. I just took a pic, but without something standing up plumb, you really don't get the idea. To tell the truth, compared to my slope, your looks like flat ground, but I'm sure it doesn't feel that way to you.
If it feels too unstable, change your pattern to perpendicular to the drive.

My thoughts on loading the tires; too hard on the tranny and adding too much weight to something that already weighs a lot to begin with.

 

[FlaDon]

I can't help you with the Gravely, but when I bought my ZTR (three mows ago) the dealer told me they can be tricky to master on a slope, that they keep wanting to turn downhill. He was right, but I wouldn't say I feel unstable. My slope is probably 30 degrees. I just took a pic, but without something standing up plumb, you really don't get the idea. To tell the truth, compared to my slope, your looks like flat ground, but I'm sure it doesn't feel that way to you.
If it feels too unstable, change your pattern to perpendicular to the drive.

My thoughts on loading the tires; too hard on the tranny and adding too much weight to something that already weighs a lot to begin with.

Mowing with any ZTR on a slope will tend for them to run downhill if moving too slow. That is a given. Adding weight to the tires is acually better for the ZTR than adding weights. 1, it isn't weight on the axles. And 2, unless you fill the tires too full, it isn't a rotating mass.