Our Italian made, Dedacciai aluminium, all-road bicycle that tackles the most variable and unpredictable surfaces with confidence and poise.

"The way this thing rides is a masterclass in bike design and engineering" | 2022.

700c, with capacity for 35mm tyres [32mm with full fenders].

The Definition is designed to deliver sporty, long-distance performance in very variable weather and surface conditions.

A go-anywhere kind of bike that can hold its own on the road while being highly adept over a range of terrains and all weathers. 



Introducing the latest evolution of the iconic Definition, the Definition 3.0. Building upon the success of its predecessor, we have made intelligent and informed changes to enhance the riding experience while remaining true to our philosophy of #RideDrivenDesign. Configurable with Shimano/ SRAM/ Campagnolo build options.

Already unique, the definitive sporty, all season, AllRoad Definition, has evolved further. Previously described as 'A masterclass in bike design and engineering' and 'Phenomenal' by, the latest version is even more refined, optimised and detailed for fast, variable surface speed and travel. 

The Definition shares the same overall geometry as our Columbus steel Resolution, but is designed to have a sportier feel, whilst still retaining the engaging, long-distance comfort and dependability that MASON bicycles are renowned for.

The premium Dedacciai aluminium frame is a super-efficient pedalling and power transmission machine. Low weight, custom shaped MASON x Dedacciai stays and large diameter down tube give it a punchy and responsive ride.

We have constantly updated, developed, and refined both the Resolution and Definition since their launch, but geometry and purpose stay unchanged. The Definition and Resolution started a new category and still remain in a class of their own. This time around, the Definition has received some changes and new features to optimise and refine for the long-distance and All-Season riding that it already excels at. With our 'Ride Driven Design' mantra as a firm guideline, we have learned a great deal from our riders and customers since it's launch in 2015 and there have been many running changes, updates and new versions as our journey has progressed. 

As always, we have been extremely careful not to 'mess with the formula' that made the original MASON Definition so magical, refined, dependable, engaging and confidence-inspiring... all year round.