When I purchased my X500 with HDAP tires the dealer brought it with turfs for me to use until the HDAP's came in.
My yard sounds similar to yours with a steep, short ditch.
When I was on a side hill and turned up the hill the turfs would spin. Then I would have to backup, square up, use the diff lock and start up hill again. With the HDAP's this doesn't happen.
I probably had to use the diff lock over a two dozen times with the turfs. With the HDAP's the diff lock is used less than a dozen times. I don't see any turf damage in tight turns but my yard is a little rough (for now).

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Are those tires taller than the standard turf tires? Looks like it might sit a little higher than my 155.

Here's a pic of the turf and HDAP tires for comparison. They are both 24x12-12. The HDAP's actual height is 25.5" and the turfs actual height is 23".

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Excellent picture...thanks. Did you get the 54" deck with those tires?

Just curious. It would appear that the larger tires would make the rear of the tractor 1 1/4" higher than with the turf tires. What does that do to the level of the mowing deck, if anything? Would it have to be adjusted?

I have a GX335 which preceded the X500. I have a 54c deck and turf tires. I also have a long hill with a slope that ranges from 15 to 22 degrees and to answer keeferb's original question, I don't think you'll have a problem with the turf tires as long as there is grass on the hill. Even at my steeper slope, I rarely need to use the differential lock even when the grass is wet. I do use it in a couple of areas where the grass is very thin.

I've been looking at the HDAP's ever since like_my_yard posted those pics of the tires side by side. The only thing holding me back is the height increase and the fact that the 54c deck is very close to the rear wheels with the turf tires and I'm not sure if there would be adequate clearance with the HDAP's. I would like the HDAP's for increased traction using my JB Jr. ad don't really need it for my hill. What size deck will you be getting with your X500?

Right now I'm leaning towards the 54" deck, but I need to find out if the HDAP tires will fit with that deck. Not sure if I'll get those tires initially, but would like that option available. I too am concerned about raising the center of gravity but would definitely like that added traction. I can traverse my slopes with my 155 so I don't always have to mow and down and I hope I can still do that with the X500.

what about the wheight of the operator?

My slope is right at the point where I would not feel safe traveling across it....I always mow it up and down. I just checked my GX335 with the 54c deck and there is around 2" between the rear tires and the back surface of the deck on both sides. There is plenty of space between the front surface of the deck and the front tires. Since your slope is a lot less steep than mine, I don't think you'll have a problem. You can also add wheel weights, suitcase weights or have your tires filled if you like.

I have a gx255 with the 54" deck. I need new tires and the HDAP would be perfect, but would they fit on my tractor or do i need to look at a smaller tire if they make that size. please help.

Below is a link to the Carlisle Tire web page with the different sizes made in the HD Field Trax design. Look up the inflated dimensions of the tires on your mower and compare them to the HD Field Trax to see if they will fit. If not, there are many other designs that might work. You can also check other brands as well.

Here is a link that might be useful: Carlisle HD Field Trax

wvhighcountry,
I don't think you will have a problem installing the HDAP's on your tractor. Measure the distance between your tires and the mower deck at their nearest point. All you need is 3/4" of additional clearance.

I tried the HDAP's on a GT235 with a 48" deck and they fit with a space left. The GT235 and GX255 are almost identical units in platform size. Here's a few pics of them on the GT235.
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