If you're shopping for a skid steer brush cutter, the first fork in the road isn't brand or width — it's deck style. Open front and closed front brush mowers cut the same brush, but they do it differently, they're priced differently, and each one is clearly better at certain jobs. This guide compares the two styles head-to-head using the Top Dog Attachments lineup so you can match the right cutter to your machine and your work.
The Core Difference: How Material Reaches the Blades
An open front brush mower has an exposed leading edge. Standing brush and saplings feed directly into the blades as you drive forward, so tall material gets cut at full height instead of being pushed over first. That makes open front decks the go-to for heavy clearing — dense undergrowth, overgrown pasture, and woody stems at the top of the cutter's capacity.
A closed front gearbox mower has a solid front deck. It rides over vegetation, laying material down before the blades finish it. You give up some aggressiveness on tall, thick stems, but you gain containment — the deck keeps cut debris from being thrown forward. That's why closed front mowers are the standard choice for roadside clearing and any work near vehicles, buildings, or people.
Neither style is "better." One is a chainsaw, the other is a lawnmower with an attitude — the question is which job you do more.
Spec-by-Spec Comparison: Top Dog Open Front vs Closed Front
Both mowers are built by Top Dog Attachments with laser-cut blade carriers, counter-clockwise blade rotation, 3/4" hydraulic hoses, flat face 1/2" ISO16028 couplers, welded-on 3/8" wear bars, and a 3,000 PSI max rating. Here's where they differ:
| Spec | Open Front Brush Mower | Closed Front Gearbox Mower |
|---|---|---|
| Cutting capacity | Up to 4½" | Up to 4" |
| Drive | Eskridge drive | Right-angle gearbox |
| Motor | 160 CC | 130 CC |
| Available widths | 72", 78", 84" | 66", 72", 78" |
| Hydraulic options | Standard flow (18–23 GPM), High flow (26–40 GPM) | Low flow, Standard flow |
| Starting price | $12,029 | $7,200 |
The open front unit is the heavier-duty machine: bigger motor, slightly larger cutting capacity, and a high-flow option that turns it into a production clearing tool. The closed front gearbox mower costs roughly 40% less and runs on lower hydraulic flow — which matters more than most buyers realize.
Match the Mower to Your Machine's Hydraulic Flow First
Before you pick a deck style, check your skid steer's auxiliary hydraulic flow rating (it's in your operator's manual, usually listed as standard flow and high flow GPM).
- Low/standard flow machines (most compact skid steers): The closed front gearbox mower is built for this range. Pairing an underpowered machine with a hungry cutter means bogged blades and slow work.
- Standard flow, 18–23 GPM: Both mowers work. Choose by job type.
- High flow, 26–40 GPM: The open front high-flow model uses everything your machine can send it. If you clear brush commercially, this is the configuration that pays for itself in acres per day.
A cutter that matches your flow rating will out-perform a "bigger" cutter that doesn't.
Which One Should You Buy?
Choose the open front brush mower if:
- You're clearing tall standing brush, saplings, or material approaching 4½" diameter
- You have a high-flow machine and want maximum productivity
- You're doing land clearing, pasture reclamation, or trail cutting away from people and property
Choose the closed front gearbox mower if:
- You mow roadsides, ditches, fence lines, or anywhere thrown debris is a liability
- Your machine runs low or standard flow
- Your material is mostly grass, weeds, and brush under 4"
- Budget matters — at $7,200 vs $12,029 to start, the closed front leaves room in the budget for a second attachment
Both are available now: Top Dog Open Front Brush Mower and Top Dog Closed Front Gearbox Mower.
FAQ
What size brush can a skid steer brush cutter handle?
The Top Dog open front brush mower cuts material up to 4½" in diameter; the closed front gearbox mower handles up to 4". As a rule of thumb, work at 75% of rated capacity for consistent, clean cutting and longer blade life.
Do I need high flow hydraulics to run a brush cutter?
No. The closed front gearbox mower runs on low or standard flow, and the open front mower has a standard flow (18–23 GPM) option. High flow (26–40 GPM) is worth it for commercial-volume clearing, but it's not required to cut brush effectively.
Is a closed front brush mower safer?
The closed front deck contains cut debris better than an open deck, which is why it's preferred for roadside and populated-area work. No brush cutter is safe without proper technique — keep bystanders well clear and follow your machine's and attachment's operating manuals.
Will these fit my skid steer?
Both mowers use the universal skid steer quick-attach plate and standard flat face 1/2" ISO16028 couplers, which fit most modern skid steers. Verify your machine's hydraulic flow rating matches the mower configuration you order.
Open front vs closed front brush mower — what's the short answer?
Open front for tall, heavy brush and maximum cutting aggression; closed front for roadside work, lower-flow machines, and tighter budgets.
The Bottom Line
Deck style is a job-type decision: open front for aggressive land clearing, closed front for controlled, contained mowing. Get your machine's hydraulic flow rating, be honest about the brush you actually cut most weeks, and the choice makes itself.
Questions about matching a cutter to your machine? Email us at sales@upnorthattachments.com — we spec attachments to machines every day.
