AS 901 SM

Professional flail mulcher with a high work rate

The AS 901 SM delivers high work rates and perfect handling whether on slopes, in dense growth or high grass. A Briggs & Stratton Vanguard Series 2-cylinder engine with 480 ccm displacement, up to 16.0 hp and an oil and fuel pump performs in tough conditions without the risk of engine damage. Propulsion occurs via a 5-speed manual transmission with reverse gear (1.8 km/h) that covers a speed range from 1.2–4.0 km/h. The rear axle differential is permanently locked, resulting in excellent traction even on wet grass. Twin tyres ensure even greater traction and stability while a vertically installed engine provides a low centre of gravity and balanced distribution of weight, at a total of 215 kg.

Operation is simple, convenient and safe

The AS 901 SM is conveniently operated via four levers. Individual wheels are controlled via a patented steering and brake clutch system by which light pressure on the wheel’s respective operating lever opens the limited slip differential; full pressure activates the brake on that wheel. Furthermore, the limited slip differential is permanently locked when in drive and the automatic parking brake engages as soon as the drive lever is released. This added safety feature stops the flail mower whether on a slope or level ground. Teflon-coated stainless steel Bowden cables ensure minimal expenditure of force. The result is safe, simple, and convenient operation.

Robust flail mowing unit

With a robust 90 cm wide flail mowing unit equipped with 26 pairs of Y-flails, the AS 901 SM is engineered for harsh conditions. The flail mower can cut grass up to 130 cm high at work rates reaching 3,600 m² per hour. The flail mowing unit is supported by pendulum bearings, delivering uniform mulching results by compensating for uneven terrain. The flails ride up and over obstacles, protecting both the engine and the operator from damage. A perforated impact guard provides additional safety.

Cutting height can be adjusted to 6 levels from 10–100 mm, while the operating bar can be conveniently adjusted laterally and in height to match both the operator and the conditions.

Product advantages

Performs on slopes

Extra fuel and oil pump with oil pressure switch optimize performance on slopes.

Robust flail mower unit (AS 901)

Pendulum-bearing supported flail mower unit with 26 pairs of Y-flails for high work rates and an extremely clean mulching result.

Automatic parking brake

When the drive lever is released the machine stops automatically, whether on a slope or level ground.

Steering and brake clutch

Single-wheel brake controls the device precisely and effortlessly.

Permanent limited slip differential

Permanently locked limited slip differential opens only when steering with the steering and brake clutch.

Lightweight and balanced

Stable, lightweight construction with double-wall mower deck and rigid square frame. Low centre of gravity for optimal slope performance.

Thrown object test (AS 901)

Tested in accordance with DIN EN 12733:2011-06.

Product details

Height adjustment

Easy cutting height adjustment with lever.

Manual transmission

5-gear manual transmission with limited slip differential and reverse gear for excellent propulsion, even on wet grass.

Adjustable operating bar

Guide bar can be adjusted laterally and in height to adapt to the size of each operator.

Impact guard

A perforated impact guard ensures a high level of operator safety.

Technical Data

cutting width 90 cm
maximum grass height 130 cm
engine manufacturer Vanguard
engine designation V-Twin
4-stroke engine, 1-cyl. / 2-cyl. /
displacement 480 cm³
maximum power 11,9/16,0 kW (hp)
rated power 10,7/14,5 kW (hp)
rated speed 3500 rpm
starting device, manual / electric /
drive, mechanical/hydrostatic /
number of gears 5
reverse gear
max. speed 4 km/h
automatic parking brake
limited-slip differential
blade clutch, electric / mechanical /
closed mowing deck
flail pairs 26
flail shape, Y / hammer /
cutting height 10 - 100 mm
both sides of the flails can be used
tank capacity 5 l
dimension L/W/H 220x104x105 cm
weight 215 kg
Changes in technology, equipment and price are reserved. Of information or illustrations no claims can be derived.


Insect scare device

Scares insects and small animals away from the mower. Three times more insects can flee in time. With respective adapters suitable for AS 62/63, AS 701/901, AS Sherpa and AS YAK.

More information »

Steel hand guard set

Additional protection for the operator.

Liquide tyre sealant “Plattfuss-Stop”

Reduces the failure times due to flat tyres (950ml)

More information »

Tilt meter

Convenient display of slope incline.

Liquide tyre sealant “Plattfuss-Stop”

Reduces the failure times due to flat tyres (20 litres); can only be used in conjunction with the pump

More information »

Pump for tyre sealant

For filling the tyre sealant "Plattfuss-Stop"; only necessary in conjunction with 20 l container

Tubeless wheel

For high puncture safety in additional use of tyre sealant "Flat-Stop".

Steel wheels

Improved traction, particularly during work transverse to the slope. Replaces outside wheels on AS 901 SM.

Customer reviews

With the AS 901 flail mower I mow the grass and vine prunings between rows at the same time. This means less work cutting and no need for herbicides.
– Martin Gehauf (Farmer and winemaker, Freyburg, Germany)
AS 901 is our constant companion in the training area. The powerhouse has to deal with 2-metre high reeds, bushes and grass. It unconditionally creates free space for the birds and insects. It is agile, powerful and is equipped to deal with all challenges.
– Oliver Thärig (National Hunting Association Sachsen-Anhalt, Germany)
We use the AS 901 SM especially on slopes, but also on straight, narrow areas. The good mowing pattern is still present even in long and dense grass. The purchase of this machine has considerably improved the safety of our staff. Another major advantage is that it makes the work easier for the staff and thus more efficient.
– Umweltbetrieb Bremen (Municipality of Bremen, Germany)
The AS 28/4 Enduro and the AS 65 Scout, which I bought second-hand, are the machines that proved their quality and gave me the confidence to go and buy my first new machine, the AS 901 SM. The power and manoeuvrability of the AS 901 SM is something that makes me approach every job with a smile. These three AS-Motor machines got me even to the point, where I want to start my own landscaping business.
– Goran Šiljak (Private user, Bosnia and Herzegovina)
My first contact with the brand was via the Internet. After the demonstration, I decided to buy AS 901 SM - I was impressed with the machine's performance – it is perfect for my orchard. A year after that, I became the owner of one more AS machine - AS 531 2T ES MK B for my backyard. I guess that's the best review and speaks for itself.
– Dragan Gligorijević (Private customer, Serbia)


Road maintenance

Maintaining roadways often involves mowing high grass and slopes, two specialties of AS-Motor’s professional technology.

Municipal maintenance

Caring for green areas in the civic environment involves a variety of tasks. From parks to roadside management, AS-Motor provides the correct tools to ensure both professional results and operator safety.

Commercial landscaping

Performance on rough terrain, perfect cutting results and high efficiency are advantages AS-Motor machines provide to professional service providers.

Gardening and landscaping

AS-Motor’s professional technology offers solutions for the diverse tasks of gardening and landscaping, from outdoor facilities to private gardens, public parks and residential lawns.

Hunting and forestry

In forests and on hunting grounds, mowing can take place as infrequently as once per year or even at intervals of several years. AS-Motor machines are engineered to tackle the thick growth native to these areas as well as Christmas tree plantations.

Meadow orchards

Meadow orchards characterize the landscape of diverse regions and provide valuable ecosystems for insect and bird life. Maintaining these areas often involves mowing around trees, on slopes and in rough terrain.

Solar parks

Efficiency is crucial to maintaining a profitable solar park. AS-Motor offers the ideal tools to properly maintain the green areas around and under solar panels.


AS-Motor offers professional technology for the maintenance of green spaces in and around public utility facilities.


Viticulture, or wine-growing, is one of civilization's oldest forms of agriculture. AS-Motor was founded 60 years ago with the objective of tackling the slopes and thick growth of vineyards.