SCUT Mowing - Ground Speed?

[ovrszd]

Here's a question for ZTR fans who get their mowing done quicker. The ZTR's advantages for trimming around obstacles are obvious. But if you figure you're going faster over open ground too, either the quality of cut is being sacrificed by going so fast or your mowing deck runs at much higher rpm's to keep up with the higher ground speed. Or maybe you mow more often so the grass isn't so heavy. I honestly want to know. At my place, the grass is heavy and going too fast means either disharge clumping or poor cut quality.

Good question!!!! I've asked it before on TBN and never got what I would call a verifiable answer. We'll see what happens here.

 

[KennyG]

I am beginning to think people lie as much about their mowing speed as their mpg and their fish size. :laughing:

 

[DK35vince]

Here's a question for ZTR fans who get their mowing done quicker. The ZTR's advantages for trimming around obstacles are obvious. But if you figure you're going faster over open ground too, either the quality of cut is being sacrificed by going so fast or your mowing deck runs at much higher rpm's to keep up with the higher ground speed. Or maybe you mow more often so the grass isn't so heavy. I honestly want to know. At my place, the grass is heavy and going too fast means either disharge clumping or poor cut quality.

I can comment on the 2 zero turns I have owned.
My lawn grows thick and fast. Generally mow about once per week.
My previous zero turn was a Hustler FasTrac 21 HP 54" deck. Top speed was 8 MPH. It would mow fine up to top speed at about any deck height setting. The reason I upsized from that mower was power. Had trouble mowing at full speed in our thick, fast growing grass it would run out of power, forcing me to slow down.
My current zero turn is a Hustler Super Z. 35hp Kawaski with a 72" deck. Top speed 14 MPH.
This mower is awesome, but cut quality at higher speeds depends a lot on cutting height with the VX 4 deck.
If the deck is set to 3+ in cut height I need to slow down to get a quality cut.
If I have my deck set at 2 1/2" or less it will cut great at all speeds.
I have my deck set at 2 1/2" on my Super Z and get a good cut all the way to the top mowing speed of 14 MPH.

 

[dakotagun]

I mow 2.5 acres. Have a JD 2305 with 60” deck, FEL and such. Don’t have a backhoe - but it would be nice 1x year. Bought a jd z-turn a couple of years ago and it runs circles around the tractor; better cut, too. I’d recommend sacrificing a BH for a ztr all day long. I haven’t used the 60” deck since; leaves the tractor in better position to be useful for other chores.

 

[ovrszd]

I am beginning to think people lie as much about their mowing speed as their mpg and their fish size. :laughing:

It's in the top three anyway.

 

[ovrszd]

I mow 2.5 acres. Have a JD 2305 with 60” deck, FEL and such. Don’t have a backhoe - but it would be nice 1x year. Bought a jd z-turn a couple of years ago and it runs circles around the tractor; better cut, too. I’d recommend sacrificing a BH for a ztr all day long. I haven’t used the 60” deck since; leaves the tractor in better position to be useful for other chores.

Would you care to give your reason why?

 

[Grandad4]

Well, having asked the question, I also felt the need to dig a little deeper myself. My 54" Kubota BX deck spins the blades at about 15,000 fpm. The 52-54" ZTR's I looked up online were showing comparable blade speeds of 18,000 - 19,000 fpm, so there is a 20-25% difference. Should mean better cut and discharge performance and also able to cover ground faster. How much faster? Side by side on the same ground, whaddya think? I'd guess maybe 20-30%, wouldn't expect it to be twice as fast.

 

[dalola]

Well, having asked the question, I also felt the need to dig a little deeper myself. My 54" Kubota BX deck spins the blades at about 15,000 fpm. The 52-54" ZTR's I looked up online were showing comparable blade speeds of 18,000 - 19,000 fpm, so there is a 20-25% difference. Should mean better cut and discharge performance and also able to cover ground faster. How much faster? Side by side on the same ground, whaddya think? I'd guess maybe 20-30%, wouldn't expect it to be twice as fast.

Bingo! Blade tip speed is the key. Commercial ZTR's have the fastest tip speeds you can buy. This is why they have superior cut performance, even at higher ground speed.

 

[WM75Guy]

Well, having asked the question, I also felt the need to dig a little deeper myself. My 54" Kubota BX deck spins the blades at about 15,000 fpm. The 52-54" ZTR's I looked up online were showing comparable blade speeds of 18,000 - 19,000 fpm, so there is a 20-25% difference. Should mean better cut and discharge performance and also able to cover ground faster. How much faster? Side by side on the same ground, whaddya think? I'd guess maybe 20-30%, wouldn't expect it to be twice as fast.

I don't see cutter vs ZTR being an apples to apples comparison. Each has it's own place, that is why I have both. You have to look at the height of the deck & blades, height & type of grass, etc. I cut with the ZTR at 3.5", my cutter is set at 6". Cutting the 12" high yard is no problem with the ZTR and it runs circles around the tractor, cutting 24" pasture grass is a different matter. The mass of the cutter blade, even at a slower speed, will help in the tall thick grass that would prevent a ZTR from giving an acceptable cut.

Now let's throw in the diesel vs gas argument. :stirthepot: That could be better than gear vs HST.

 

[Atchuuu]

Well, having asked the question, I also felt the need to dig a little deeper myself. My 54" Kubota BX deck spins the blades at about 15,000 fpm. The 52-54" ZTR's I looked up online were showing comparable blade speeds of 18,000 - 19,000 fpm, so there is a 20-25% difference. Should mean better cut and discharge performance and also able to cover ground faster. How much faster? Side by side on the same ground, whaddya think? I'd guess maybe 20-30%, wouldn't expect it to be twice as fast.

The 60" woods Brushbull has a speed of around 14,000 rpms. My Zero turn is around 18,000. But you also have finish blades on the zero turn. The BH has thicker blades and will cut up to 1.5" diameter. So it is difficult to compare cut quality.

I have found that it is not possible to run full speed on my 42" residential grade Exmark. It will run at 7.5 mph but will beat you to death as there is no suspension. My guess is that a tractor at 3.5-4 mph with a 60-72" deck will take just as long or perhaps a little longer to cut.

A couple of benefits to the tractor in my particular situation is the following; Tractor is a muti-purpose tool if you have the FEL. You don't have to stay on top of all of the grass year round. If you let it get too long you lose the time saving benefit of the ZTR.

On the other hand many ZTR's are cheaper, easier to transport, fit in a garage and have a beautiful finish cut. In a perfect world we would all have both.