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. 



The thinking behind both the Definition is to create A true ‘4Season’ AllRoad bike, for comfortable long-distance rides in very variable conditions. The Definition shares the same overall geometry as the steel Resolution, but is designed to have a sportier feel, whilst still retaining the long distance comfort and dependability that MASON bicycles have become known for.

This is not a lifeless ‘do it all’ machine but a spirited ‘multi-discipline’ bicycle, designed to cover ground fast and retain poise over very variable road conditions.

By using clever tube manipulation, advanced tubing and sensible design, a modern aluminium frame can rival composite on weight and ride feedback and quality. Modern aluminium frames - such as the Definition - draw on many of the design influences learnt from composite frames, such as oversized BB’s, taper head tubes and switchable internal routing. Teamed with a properly designed carbon-monocoque fork, the contemporary Aluminium frame is a formidable piece of kit.