AS 901 SM Flail Mower 90cm Professional Slope Machine

The AS 901 SM is a 90 cm walk-behind flail mower built for banks, rough ground and areas where a tractor or ride-on isn’t safe. Its Vanguard V-Twin engine, locked differential and steady gearing give it the push to get through dense growth while keeping control on awkward slopes.

It suits contractors, local authorities and estates that need a dependable machine for tall grass, brash and mixed ground. The pendulum-mounted flail deck handles uneven terrain calmly, and the automatic parking brake adds confidence when working across or down banks.

Working capability and real-world use

The AS 901 SM is built for ground where lighter mowers struggle or where a ride-on simply isn’t safe. The 90 cm flail rotor with 26 pairs of Y-flails keeps a steady cut through tall, heavy growth, handling everything from coarse grass and weeds to brash left from seasonal clearing. The pendulum-mounted deck follows the ground without transferring every bump to the operator, which matters when you’re working across ruts, molehills or broken banks.

Where it fits in AS-Motor’s range

Within the pedestrian flail line, this is the high-output option. Compared with the AS 701 SM, the AS 901 SM offers more power, a wider cut and higher throughput. Buyers usually step up to this model when they have open stretches of rough ground or long banks where the extra width pays off. It also sits above the Allmäher high-grass models for work that leans more towards mixed scrub, debris and unknown terrain rather than pure long grass.

Who the machine suits

• Contractors maintaining roadside banks, drainage channels, solar sites and rough estate ground
• Councils and highway teams needing a safer alternative to ride-ons on steep or narrow verges
• Large estates and farms with awkward access, ditches or areas left to grow for long periods

It’s typically bought by people who already operate machinery and need a walk-behind flail to cover the ground they can’t access by tractor. The engine pumps and low centre of gravity give it the stability needed for serious banking, while the permanently locked differential keeps the machine moving on wet grass and uneven surfaces.

Strengths that matter day to day

• Strong mulching ability in long, dense material where rotary systems lose momentum
• Predictable handling on slopes thanks to its balanced frame and automatic parking brake
• Reliable traction from the locked diff, with steering and brake clutches for tight manoeuvres
• Pendulum deck that absorbs unevenness and helps protect the rotor from hard hits
• Adjustable operating bar that makes long sessions less tiring for different operators

Operational realities

The machine’s weight helps it stay planted on slopes but means it needs a planned approach in tight spaces. It’s not designed for small, stop-start gardens or weaving between close obstacles all day. Where it excels is steady forward work on banks, long verges, orchard margins, solar sites and rough areas where other machines either bog down or pose safety risks.

Accessories worth considering

• Steel wheels: improve bite when mowing diagonally across banks
• Steel hand guards: protect controls and hands in brashy material
• Operating hour meter: useful for service intervals on contractor fleets
• Tilt meter: helpful for training staff and managing slope work more safely

How Suffolk Mowers Supports Your Purchase

Suffolk Mowers supplies the AS 901 SM ready to work, with setup, pre-delivery checks and clear handover so you know how to handle the machine safely on banks and rough ground. We stock common wear parts, flails and service items, and can order genuine AS-Motor components quickly when needed.

Our workshop handles routine servicing, repairs and mid-season checks for contractors and estates who rely on the machine through heavy use. If you want advice on accessories such as steel wheels or hand guards, we’ll walk you through when they make a difference and when they don’t. The aim is simple: keep your machine cutting cleanly, starting easily and working safely throughout the season.

Technical Specifications

Frequently Asked Questions About AS 901 SM