Rear Finish Mower How wide of a RFM can I run properly?

[jimgerken]

With my JD 2520 (26 Hp deisel, hydro, so maybe 22 PTO Hp), how big of a rear finish mower could I run? The choices are 60 inch or 72 inch. Each is 3-blade, rear discharge. Driveline is 540 pto, right angle gearbox, two "B" vee-belt distribution on deck. The area to mow is lawn grass, all nice and level, 2 acres in a nice 80x1000 chunk. However, sometimes the mowing is neglected and I skip a week, so it gets overgrown. I don't mind having to overlap a little more if the grass is thick. What do you guys think, can I go for the big 72 incher? I appreciate your input, thanks!

 

[Ductape]

I ran a 60 with 18hp (about 15 @ PTO). I will say that it did work when the grass was long. If you keep up with it pretty well, i should think you'd be OK with a 72.

 

[greg_g]

John Deere says you have 20.5 PTO hp
http://www.deere.com/specsapp/CustomerSpecificationServlet?sbu=CCE&pciModel=2520%20LV&displayModelName=2520%204WD%20Compact%20Tractor%20(26.5hp)&tM=GC&pNbr=0160LV
Rule of thumb I use is based upon rotary cutter sizing; one foot of rotary cutter swath for each 5 PTO horsepower. Then I add a foot to arrive at the finish mower swath. That said, your 2520 should handle a 4' bush hog and a 5' finish mower. Depending upon conditions, anything bigger than that might slow you down.

Mower weight is also a consideration. Yes, the 2520 hydraulics are rated to lift 1150 pounds. But - without a front loader for counterweight - the weight of a quality 6' finish mower might cause some control problems.

//greg//

 

[jbrumberg]

jimgerken:

There has been a lot of previous discussion here at TBN regarding RFM's and PTO HP, but I agree with greg g for all the reasons mentionned. Jay

 

[Runner]

My experience is that the 2520 has plenty of power for a 72 inch rear finish mower (mine is a Frontier GM1072R). You mention that your property is flat, in which case, I wouldn't hesitate to use this mower. However, my property is very hilly and the mower tends to drag the back end of the tractor sideways on the hills.

Also, due to the weight of this mower (about 675 lbs) I have to use four wheel drive virtually all of the time to get enough traction to pull it around. Maybe it would handle a 60 inch RFM better, but they don't weigh that much less, maybe 50 lbs or so, so I doubt it.

Otherwise, I love this mower and it does a beautiful job of cutting. However, I don't like the idea that I have to be in 4WD ALL the time to mow my 2 acres. Therefore, I'll be trying a 62D belly mower on this machine in the spring to see if I like it better.

Here's a pic of the unit:

 

[jimgerken]

Thanks for all the input. Does anyone have a feeling about the power requirement difference between side discharge and rear discharge?

 

[greg_g]

Thanks for all the input. Does anyone have a feeling about the power requirement difference between side discharge and rear discharge?

Unless you have a specific reason to windrow the clippings, I definitely recommend the rear discharge design.

//greg//

 

[ovrszd]

Runner, not sure if you always use your quick hitch, but in the pic it's used. If you take it off and hitch the RFM directly to the tractor you will minimize the side drag and help with the lifted weight when carrying it. Not sure that will help with the 4wd issue though.

 

[prosperity]

Runner, not sure if you always use your quick hitch, but in the pic it's used. If you take it off and hitch the RFM directly to the tractor you will minimize the side drag and help with the lifted weight when carrying it. Not sure that will help with the 4wd issue though.

Also, hard to tell in the photo, but are you using any weight on the front of the tractor?

I have a 2520, and when using my 4' bush hog, I put 7x42# suitcase weights on the front - makes a huge difference in handling a rear implement like this.

 

[rbargeron]

I agree with you that if you get the 72" you can always overlap more and/or go slower if the crop is dense. If the grass is light the 72" will get it done faster.
And 4 castors with floating hitch arms make any RFM seem much lighter from the seat.