Rear Finish Mower 72" or 84" rear finish mower?

orange1 · Sep 4, 2005

72\" or 84\" rear finish mower?

I am looking to purchase a 30 hp compact. Leaning towards NH TC33DA. I will be mowing a 4.5 acre field with the mower. The field has only 3 trees - it is wide open. I have a ztr for other areas around the house. My question is can I use an 84" deck for the rear mount mower with this tractor or would the 72" deck be better and why? Also, what about box blade and landscape rake. What size implements would be best with this size tractor? Any thoughts would be greatly appreciated.

Devildog · Sep 4, 2005

Re: 72\" or 84\" rear finish mower?

O1,
IMHO I think if you have a ztr it would be alot faster. I just got a 72" RD RFM but havent had the chance to use it yet. We got almost 4acres where were moving to. I would like to have a ztr to mow it with but just couldnt asorb the extra cost right now. Hopefully someone else will chime in. Jim

RoyJackson · Sep 4, 2005

Re: 72\" or 84\" rear finish mower?

A question first...you want to mow a 4.5 acre field...is this a lawn (grass) or a field (rougher stuff then a lawn). If it's truly a field, you may want a rotary cutter instead of a rear finishing mower.

The TC33 has about 27 PTO horsepower on the hydro transmission model.

Per the Land Pride and Befco (finishing mower requirements), you should be able to run an 84" unit. You've got the horsepower for it...bit on the low side though.

As far as which would be better...that depends on your land and how frequently you intend to mow. If the property is completely flat with no ruts, small hills and such, I'd lean toward the 84" unit. If there are small or abrupt changes in the topography, the 84" one will be more likely to scalp then a narrower unit. If you mow regularly, you shouldn't have a problem. If the grasses do get a bit high, you can always make a partial width pass or slow down a bit.

If you acreage is a field, you'll want a rotary cutter. Depending on the type of grasses or brush, a 72" unit is as big as you'd want to go. Again, depending on conditions, you may have to make partial passes. You may want to consider a 60" unit, considering your PTO horsepower. With a cutter, 3PH lift capacity comes into play. Those cutters are pretty heavy (my 60" land Pride goes about 625# vs. about 450# for a 60" Befco finishing mower).

With either a finishing mower or a cutter, front weights will be a necessity. If you decide upon a cutter (rather then a finishing mower), you might want to look into a pull-behind unit rather then a 3PH type.

Dargo · Sep 4, 2005

Re: 72\" or 84\" rear finish mower?

I'd prefer the 84" deck, but unless you have sparse grass or you mow a minimum of every 5 to 7 days, you will definitely not have enough hp for the 84" deck. If you have thick grass and you miss a week, you'll not enjoy the attempt at mowing with an 84" deck and 30 hp. For thick grass or for less than weekly mowings, I'd recommend at least 50 PTO hp for the 84" deck. But, hey, that's just me. I personally do not like mowing in 1st gear, low range, and having to shove the clutch down every 5' to let the engine keep up.

orange1 · Sep 4, 2005

Re: 72\" or 84\" rear finish mower?

Thanks for the advice. The 4.5 acres is grass. I have mowed it with my 61" cut Scag ztr but it is a little bouncy. The ztr had no problem mowing the grass down even though it was overgrown. It just feels like I should be mowing it with a tractor. The topography is mostly flat with no steep inclines. Like I said there are only 3 trees in the field. This is why I have to at least consider the 84" rfm. I will be mowing the grass regularly.

ns_in_tex · Sep 4, 2005

Re: 72\" or 84\" rear finish mower?

I mow with a 84" rear finish mower on a 39 PTO tractor. When I slow down, it is to protect the belt drive. IMO a smaller HP would handle it OK if the weight of the tractor can handle the larger mower when picking it up.

I also think a rear discharge unit will not load up as fast as a side discharge.

I just wish I could come up with a way to get 540 pto at about 2/3 the engine rpm required now.

have_blue · Sep 5, 2005

Re: 72\" or 84\" rear finish mower?

orange1,

You have a win-win situation. A clean 4.5 acres can be mowed quickly with the 72", and lickety-split with the 84". If you had say 7 acres or more, I would say definitely go for the 84. A foot wider deck makes a substantial difference in mowing time on a larger field.

To me, it's doggoned near to flipping a coin. I would consider budget and maneuverability. If that's not a problem, get the 84. You seldom hear any regrets for getting bigger implements. But,,, OTOH, the 72 is a good fit for your land.

In my experience, the TC33 will pull a 5' box blade well, but struggle with a 6 footer. You can pull the 6 footer, but will have to go slowly.

kayssupply · Sep 5, 2005

Re: 72\" or 84\" rear finish mower?

If you had a Grey market tractor you could just put it in 2nd PTO gear and get 540 at about 1800rpm.

ns_in_tex · Sep 5, 2005

Re: 72\" or 84\" rear finish mower?

I do that with my Hesston tractor, but it is a little big for the lawn.

TractorLegend · Sep 5, 2005

Re: 72\" or 84\" rear finish mower?

I have a 72 on the back of my Kioti CK30HST. Im glad I didnt go bigger on my lot cause wider would make loader duties less manuverable in my case. Lifes a big trade-off of choices.
Good luck!