Mowing Rotary Cutter Width for B21?

johntlyon · May 7, 2012

I'm sourcing a rotary cutter/mower for my B21 and I would like to know what is the correct size (width) for this tractor.

The Operator's Manual says 42" max cutting width for rotary cutter (1-blade) but the dealer says a 48" Land Pride (model RCR1548) will work. A trusted friend says the rotary cutter should be at least as wide as the wheel tracks (tractor width is 53.7") which might put me at a 60" wide rotary cutter.

Suggestions?

bcp · May 7, 2012

Depends on what you are cutting.

Bruce

Oldtractorfixer · May 7, 2012

In a perfect world your mower should be as wide as your track. Unfortunately you have your wheels out a little and don't have enough power for a mower that big. If you go bigger than the factory recommendation you will have to go very very slowly when the material gets at all heavy and may even have to stop and let the machine clear from time to time. You will be much happier if you stay with the factory spec or close to it. You are probably ok with the 48 but no bigger.

AStanton · May 7, 2012

Go on you tube, two brothers from Ahern Kubota have a B21 running a 48" cutter. Their handle is "the Tractor Guys." Personally, I won't worry about the wide of the cutter being wide as your tires and I won't run anything bigger than a 48". A cutter that is underpowered and boggs down because it is too wide is worse than not filling the tires width.
This is my opinion, and I don't need any old ladies to chime in and tell me that I'm wrong and full of beans.

MarkV · May 7, 2012

I have been using a 48" rotary mower on my B21 for the past 10 years. I would not go any wider. Even at 48" if you are in heavy pasture grass you will be slowed down somewhat. Keep in mind you only have 13 PTO horsepower.

MarkV

Ken45101 · May 8, 2012

Probably if you keep it maintained and cut frequently, you can go a bit wider than the factory reco. But if you only cut it once or twice a year, you will have to creep with a wider cutter. Of course, when the going gets tough, you can just cut half width.

Heavy, thick, lush early season grass is harder to cut than later season when it is dried out and shatters more easily.

Ken

art · May 8, 2012

We normally put a 5' behind that chassis which is the same as the 3030 Kubota.

MarkV · May 8, 2012

art said:
We normally put a 5' behind that chassis which is the same as the 3030 Kubota.

Do you really Art, with 13 PTO horsepower? I would like to, but I don't think mine would handle more than the 4' mower with any efficiency.

MarkV

johntlyon · May 9, 2012

Thanks very much for for the replies and helpful information. I found a used John Deere 413 48" rotary cutter advertised on CL for $750. Is it compatible with a Kubota B21? (Is it OK to mix orange and green like that?)

I am also thinking of a new Land Pride RCR1248 from the Kubota dealer.

Sure appreciate any thoughts!

AStanton · May 9, 2012

I would look at the pto shaft for both implements. If one used a shear bolt and the other a slip-clutch, I would opt for the shear bolt. Now I know some old ladies will chime in over this comment. Shear bolt-no maintenance; slip-clutch-maintenance.
Also check the length on the pto shaft that comes with the implement and make sure it is the right length for your tractor. If the shaft is new, it may have to be cut. You need about 2" of play. If you don't know what I'm talking about, then have someone who knows check the shaft before your run it.
Good Luck