ALLETT KENSINGTON 20B Petrol Cylinder Mower

The Kensington 20B: Allett’s Flagship Cartridge Mower for Domestic Lawns

If a perfectly striped, beautifully manicured lawn is your goal, the Allett Kensington 20B Petrol Cylinder Mower delivers the professional results you’ve been looking for. As the largest model in Allett’s acclaimed Kensington range, this mower has been developed for passionate gardeners who demand professional standards, pristine presentation, and the kind of long-lasting results only a premium machine can deliver. With its powerful build, wide cutting capability, and many advanced features, it represents the peak of domestic mowing technology, in one exceptional package.

Powerful Engines Designed for Consistent Results

The Kensington 20B is built to handle larger lawns with ease, offering a choice of two tried-and-tested petrol engines that suit different user preferences. You can opt for the 127cc Briggs & Stratton XR550 or the 122cc Honda GX120, both of which are engineered for dependable, smooth-running performance. These four-stroke engines use a recoil start system and have been carefully selected for their ability to deliver consistent drive and cutting power across varied types of lawn.

With a 20-inch (51cm) cutting width and 2-litre fuel tank, this petrol mower is perfectly sized for lawns up to 900m². It’s designed to complete each session efficiently without constant refuelling interruptions. The self-propelled drive system provides a steady pace, reducing operator fatigue and allowing you to focus on keeping lines straight and your finish immaculate. Even with this level of performance, the Kensington 20B runs at just 96 dB(A)—surprisingly quiet for a petrol mower of this class, making it a neighbour friendly machine.

Precision Cutting Tailored to Your Needs

Exceptional lawn presentation starts with a clean cut, and that’s exactly where the Kensington 20B shines. Its six-bladed cutting cylinder delivers an impressive 79 cuts per metre, slicing grass with a scissor-like motion that avoids tearing and helps promote healthier growth.

To give you full control over the result, Allett includes a micro height adjustment system that allows cutting heights from 6mm to 32mm. This simple yet highly precise mechanism helps you tailor the finish to both the season and your personal preferences, whether you’re creating a croquet-ready lawn or lush domestic green.

A Healthy Lawn with Clearly Defined Stripes

Stripes are the signature of a well-kept British lawn, and the Kensington 20B achieves them with aplomb. It’s fitted with a zinc-plated front roller and two-piece rear steel roller with differential, which work together to press clear, sharp stripes into the turf as you mow. The differential ensures smooth turning without marking the grass, even on tight corners, giving you freedom of movement without sacrificing the finish.

A spring tine comb lifts the grass before cutting to ensure an even trim, while the adjustable rake clears moss, debris, and surface material to enhance lawn health and appearance. These integrated tools work in harmony to create a uniform, vibrant surface that not only looks fantastic but feels great underfoot.

Incredible Versatility with the QX Cartridge System

Another thing that sets the Kensington 20B apart from the competition is its all-season flexibility. Thanks to Allett’s Quick Exchange (QX) cartridge system, you can remove the cutting cassette and replace it with one of their lawn care attachments—no tools are required. This means you’re not just investing in a mower; you’re building a complete lawn maintenance system.

The cartridges are available to buy separately, and include a scarifier, aerator, dethatcher, Verticut unit, and lawn brush, each designed to address specific seasonal or situational needs. For gardeners who pursue immaculate finishes, a ten-bladed cylinder can also be purchased to produce an even finer cut. This cartridge system allows the Kensington 20B to evolve with your lawn, adapting to its changing needs over the years.

Comfortable Handling and Spacious Grass Box

While the Kensington 20B is a serious garden machine, it has still been designed with the user’s comfort and convenience in mind. Weighing 56.6kg including the grass box, it offers the stability needed for straight, consistent mowing, yet remains balanced and responsive when navigating complex layouts. Its solid construction supports confident handling across both flat and undulating ground.

The handlebars can be adjusted to three different heights, helping you maintain an ergonomic posture and reduce fatigue during longer mowing sessions. For transport and storage, the handlebars fold down neatly, making it easier to fit in smaller sheds or vehicles. An auxiliary wheel kit is also included as standard, raising the chassis to better handle taller grass, while maintaining consistent cutting results.

Another key practical benefit is the 70-litre grass collector, which provides generous space for clippings. Made from high-impact polypropylene, it’s quick to detach, easy to empty, and robust enough to handle frequent use across the seasons.

Top Quality Backed by British Heritage

Allett is one of Britain’s leading names in garden machinery, known for precision engineering and a deep understanding of what great lawnmowers look like. Building on over 60 years of manufacturing experience, the Kensington 20B reflects the company’s expertise in every detail, from its durable steel body to its responsive cutting system and intuitive controls.

For your added peace of mind, Allett supplies this mower with a two-year domestic warranty. For those using it in professional or sports settings, a three-month Sports Pro warranty is provided.

Invest in Excellence – Order the Allett Kensington 20B Today

If you’re serious about achieving a lawn that turns heads for all the right reasons, the Allett Kensington 20B is for you. Offering wide-area cutting, high-precision stripes, and all-season versatility through its cartridge system, this superior mower is a trusted partner for perfectionists who value both performance and presentation. Order yours today and experience the difference that exceptional engineering and true British craftsmanship can make to a lawn.

Take a Closer Look at the Allett Kensington Cylinder Mower Range