Spade rotor or two-blade deck? The answer is decided by what is growing.
If you are cutting standing brush, bramble, saplings or verges taller than a metre, buy a spade rotor: 54–66 free-swinging blades that mulch stems to about 30 mm and take growth up to 3 m. If you are maintaining grass, orchard rows or estate lawns, buy a two-blade deck: cleaner finish, lighter machine, lower price.
How a spade rotor cuts
A spade rotor is a horizontal shaft carrying 54 or 66 free-swinging blades inside a heavy steel housing. Each blade is hinged, not fixed: hit something it cannot cut and it folds back instead of transferring the shock into the shaft.
Because the blades are free-swinging and numerous, the rotor does not need material to be lifted or aligned. It hits the same stem repeatedly at high speed until the stem is broken into mulch. That is why the same machine leaves 2 cm stubble on grass and still walks through a 3 m wall of weeds.
Two consequences follow. The finish is rougher than a blade deck, and the machine needs more power per centimetre of cut — which is why the rotor models carry 14–16 hp engines and a 2,500 W generator, and weigh considerably more than the P series.
How a two-blade deck cuts
A two-blade deck works like a scaled-up lawn mower: a horizontal blade bar rotating under a shallow pressed deck, generating lift to stand the grass up before cutting it. It produces a clean, even finish and throws clippings in a controlled direction.
It is also the wrong tool for brush. In a mat of bramble the blade cannot lift the material, so it stalls against it; saplings blunt the edge and shock-load the spindle. The P series compensates with a lighter chassis and an electric actuator for cut height, which makes it genuinely useful in orchards and on estate lawns — not in scrub.
| Condition | Spade rotor (MA-80 / 100) | Two-blade (MA-50P / 80P) |
|---|---|---|
| Maintained grass under 15 cm | Works, rougher finish | Best finish |
| Grass 15–50 cm | Two passes, fine | One slow pass |
| Standing weeds 1–3 m | Designed for it | Stalls, needs pre-cut |
| Saplings to 30 mm | Mulches | Damages spindle |
| Bramble and vine mat | Breaks it down | Cannot lift it |
| Transport | Trailer, 163–170 cm chassis | Fits a pickup |
| Purchase price | Higher | Lower |
Not sure which rotor
Send a photo of the worst patch with something for scale. We will tell you which rotor survives it — and if the answer is “neither”, we will say so.
One business day · no obligation
Range at a glance
| Two-blade | 500 / 800 mm |
| Spade rotor | 800 / 1,000 mm |
| Blade count | 54 / 66 |
| Max growth | 3 m |
What it costs to cut an acre of bank
Illustrative model, not a quote. Labour at US$35 per hour fully loaded; machine cost amortised over three years at 200 hours per year.
| Method | Output | Labour per acre | Labour cost | Machine cost | Total per acre |
|---|---|---|---|---|---|
| 3-person strimmer crew | 0.15 acre/h | 20.0 h | $700 | $0 | $700 |
| Walk-behind slasher | 0.25 acre/h | 4.0 h | $140 | $6 | $146 |
| Zero-turn, 60 in deck | not rated | — | — | — | cannot operate |
| MAGNUS MA-100-2 | 0.70 acre/h | 1.4 h | $50 | depends on model | labour $50 |
We deliberately leave the machine cost blank: it depends on model, configuration, freight and duty. What the table shows is the labour delta, which is the part that does not change with negotiation. A tracked mower removes 18.6 of the 20 labour hours per acre.
And a zero-turn?
The comparison buyers usually arrive with.
On flat, open, maintained turf a zero-turn is simply faster — roughly three to four times the output of a 1,000 mm remote mower — and it leaves a better finish. If your work is flat lawns, buy the zero-turn; a remote mower will lose money on throughput alone.
The comparison only becomes interesting when the ground tilts. Most commercial zero-turn manuals limit operation to about 15°. Above that, hydrostatic traction degrades and the rollover risk rises sharply. The remote mower’s advantage is not that it cuts faster; it is that it cuts at all, with nobody on the machine.
For a mixed contract the honest answer is often both machines: the zero-turn takes the lawns, the tracked mower takes the banks and the scrub. Compare the specifications before deciding which to buy first.
Rule of thumb. If at least 30% of your monthly cut area is ground a zero-turn cannot safely handle, the remote mower pays for itself within a season. Below 15%, it usually does not.
Decision rules
- 01Mostly grass, some brushTwo-blade P series, 800 mm. Add a rotor machine only when brush becomes routine.
- 02Brush, verges, scrubStandard spade rotor. Choose 800 mm for access, 1,000 mm for pass count.
- 03Uneven or terraced groundSA series. The adaptive deck earns its premium on contour, not on flat ground.
- 04Fleet or rentalMix one 1,000 mm rotor machine with one 500 mm P model; they cover the widest range of jobs.
Comparison questions
Is a spade rotor better than a two-blade deck?
Neither is better in general; they solve different problems. A rotor mulches saplings and standing growth to 3 m; a two-blade deck gives a cleaner finish on maintained grass on a lighter machine.
How much does it cost to cut an acre of steep bank?
A three-person strimmer crew typically costs several hundred dollars per acre in labour on a steep bank. A tracked remote mower with one operator costs a fraction of that once machine depreciation is included.
Can a two-blade remote mower handle brush if I go slowly?
Up to a point. Grass and soft weeds to about a metre, yes. Woody stems and bramble mat, no — the blade cannot lift the material and the spindle takes the shock. Pre-cutting with a brushcutter defeats the purpose of buying the machine.
Not sure which deck you need?
Describe what is growing and how thick it is. We will name the rotor and the model that handles it.