60 inch vs 72 MMM how much faster?

[4570Man]

That's the part he isn't getting. Adding a foot to the width won't decrease his mowing time. It might even increase it because he may have to travel slower to get the same cut. I can almost mow an area faster with my 42" riders than I can with the 60" MMM because they take bumps and rough ground better and have a tighter turning radius. If his terrain is relatively lever and clear, his money may be better spent on a ZTR.. I can't use one due to my slopes.

I hear that all the time but I mow a lot of yards and I’ve never encountered one yet that I couldn’t mow on my ZTR. If you’re mowing it on your 42” rider it’s a 100 percent safe bet I can do it on my Grasshopper. I’ve got you beat bad on traction and center of gravity. And a 60” deck will never outperform a 72” based on hp limits alone. Not being able to fit is another set of problems. If the grass as light or the ground is rough you can’t go fast enough to use your HP and you’re wasting work. When the going gets tough and you’re going marginally faster with the 60” the same amount of work is still getting done. Or if it would make you feel better I could just overlap more and cut 60” with the 72” deck.

 

[chim]

Real life information. We had 2-1/4 acres that I mowed for over 20 years with 5 foot decks (both MMM and RFM) and at a sensible speed it took about the same amount of time regardless of deck - between 1.25 and 1.5 hours. In 2012 we increased the yard to 3-1/2 acres and at the same time went to a 6 foot RFM. The mowing time remained the same as it was for 2-1/4 acres with more horses and the 1 foot wider deck. The yard has some trees, sheds, a creek and a couple other obstacles.

Due to the need to overlap, a 5' deck may cut about 54" after that first pass while a 6' deck will cut 66". That works out to 5 fewer passes on an area 150' wide.

Starting in the Spring of 2019 I went to a 7-1/2' RFM and it allowed a more leisurely pace but still cut down on the time. Last week I mowed to "git 'er done", but still didn't travel fast enough to be hard on me or the equipment. I used the stop watch on the phone because I was curious to see how long it would take. Below is a screen shot of the stop watch.

It can take longer if I'm mowing after dark, or doing cute patterns. Cutting at the rate of 16 minutes per acre while cruising comfortably works for me. I could have sworn it took about 20 minutes an acre last year.

 

[todd92]

My JD2210 uses a 62" deck with ease. Would handle a 72" deck with a slightly slower pace in heavy mowing.

Otherwise, a 72" deck is 20% bigger. If same ground speed is used, you gained 20% more ground covered. If we convert that to time, you'd save 20%. So you'd do the same mowing as your example in an hour and 18 minutes rather than an hour and 30 minutes. Saving 12 minutes each time you mow. In 7 mowings you would gain 1.

83% of 90 minutes is 75 minutes, not 78 minutes. You also have to factor in overlap. Assume 6" overlap, so the effective cutting width of each deck is 66" and 54". So it's 82% not 83%. 74 minutes.

 

[mikester]

If you want to save time get a commercial ZTR. I went from a 72" 3PH deck on the tractor to a 60" ZTR and I cut in about about 1/4 the time.

 

[shooterdon]

Fast and MMM are mutually exclusive terms.

But everyone has different situations and expectations. In my case, I do not enjoy cutting grass. Therefore, I am prepared to pay a premium to reduce seat time. It takes me about 90-120 minutes to cut my grass using a 48” rider. It seems silly to invest $5-6000 to save 45-60 minutes each time for the 20-25 times a year I cut grass....and it is. (20 hours a year time saved for 20 years would mean my time is worth $15/hr....and it isn’t worth that). But it is my money to “waste” if I chose to.

 

[ovrszd]

83% of 90 minutes is 75 minutes, not 78 minutes. You also have to factor in overlap. Assume 6" overlap, so the effective cutting width of each deck is 66" and 54". So it's 82% not 83%. 74 minutes.

Thank you for clearing that up.

 

[ovrszd]

Fast and MMM are mutually exclusive terms.

But everyone has different situations and expectations. In my case, I do not enjoy cutting grass. Therefore, I am prepared to pay a premium to reduce seat time. It takes me about 90-120 minutes to cut my grass using a 48” rider. It seems silly to invest $5-6000 to save 45-60 minutes each time for the 20-25 times a year I cut grass....and it is. (20 hours a year time saved for 20 years would mean my time is worth $15/hr....and it isn’t worth that). But it is my money to “waste” if I chose to.

I'm a multi-purpose guy. I struggle purchasing a machine that will only do one thing.

If I could get over that I'd have a zero turn. But at 68 I'm probly not gonna get over that.

If only I could wear out this 16 year old JD....

 

[Rebeldad1]

hour and a half divided by 1/6=

 

[jwstewar]

I mowed for 17 years w/ a 60" MMM on a New Holland TC24D. Depending on how the tractor was configured - you might figure a half hour to an hour to take off a 3 pt attachment, put the mower deck on, and take the loader off. Then 4.5 - 5 hours to mow. Then another half hour or so putting the tractor back to how it was before if so needed. I sold the New Holland and bought a Spartan Zero Turn with a 72" deck and a Kubota L3301. Now I hope on the Spartan and I'm done mowing in just over 2 hours. Park the Spartan and hop on the tractor and I'm hauling hay or manure in about 2 minutes - however it takes me to get something to drink after finishing mowing.

When I mowed w/ the NH, it was always hot as heck from the hydrostat and the mower gear box right below me. I was always filthy and my back would hurt from the rough ride. The tractor was loud and I had to wear hearing protection - and my ears would sweat and I would end up with an ear infection once or twice a year. Now that I have the zero turn, I don't feel any heat, I'm going fast enough I actually get a breeze. It has 4 wheel suspension and a suspension seat. My back doesn't hurt and no headache. And it is quiet enough I don't have to wear ear muffs, so no ear sweat, LOL.

 

[shooterdon]

I'm a multi-purpose guy. I struggle purchasing a machine that will only do one thing.

If I could get over that I'd have a zero turn. But at 68 I'm probly not gonna get over that.

If only I could wear out this 16 year old JD....

Richard, I am in a similar pickle. I want my Husqvarna to die so I can justify getting the ZT. But it still does the job and I am too cheap to buy a better machine that saves me 20 hrs a year of sitting on my butt. Unlike you, a need a machine that only cuts grass. My LS is way too big for the job.

I will keep changing oil on the Husqvarna every second year until it finally needs serious work, unless I win the lottery, or take a stupid pill and then get a ZT. I have 8 years and about 200-250 hours on it...not sure on the hours as I left the ignition key on for most of a winter. The Amish guy who runs the small engine place I frequent told me the engine is good for over 1000 hours....dear Lord I hope he is wrong!! At 70, I do not want to wait another 24 years. Maybe the hydrostatics will fail first....lol.