A drop bar steel bike to tackle steeper, tougher terrain, snow and sand

The new Mason ISO is designed to take you further off road, while still allowing you to ride further and faster. The ISO’s frame and fork have the clearance for 2.4 inch 700c tyres or 2.8 inch 650b. That’s a serious amount of rubber, letting you tackle steeper, rougher, deeper terrain.

It’s a gear up in off road capability from Mason’s Bokeh all-terrain machine.

According to Dom Mason: “We found ourselves taking the Bokeh to territory and terrain that we had never imagined riding with a bike like this. Josh [Ibbett] found himself deep in the Mexican desert, fully loaded in deep sand.

“I found myself smashing down blue runs in the French Alps and linking runs together on isolated, steep, Rocky Mountain trails. The Bokeh handled this stuff incredibly well, it was amazing fun but it got us thinking again and after a long distance call from Josh (he was actually in his bivvy bag way out in the desert), I started sketching.”

You can fit 2.8 inch 650b tyres and a dropper post to the ISO

TLAs for bike names seem to be a thing at the moment, with Kinesis launching the RTD this week. In Mason’s case, ISO stands for InSearchOf.

To handle tough rides, there’s the option to fit a suspension fork. More extreme braking needs are catered for by flat mounts allowing you to use 180mm or 160mm rotors. You can fit a dropper post cable too.

The ISO adopts Boost axle spacing from mountain bikes to handle the wide tyres. That’s 15x110mm at the front and 12x148mm at the rear. Although the ISO frame is designed for single ring groupsets, you can fit a band on front mech.

ISO’s front mudguard doubles as a carrier for loads up to 500g. There’s a channel in the fork leg for a dynamo cable

Mason hasn’t forsaken the bikepacking adventurer either, with lots of mounting points, mudguard and rack eyelets, a bespoke front mudguard capable of supporting a 500g load and custom racks. The Hot Shoe fork includes rack and mudguard mounts and allows a dynamo cable to be run internally through the right leg.

The ISO frameset is made from a mix of custom Dedacciai Zero steel tubing, with a Reynolds 853 seat tube and a stainless steel bottom bracket shell. For the ISO’s dropouts, Mason has paired up with Bear Components, who also make the neat rear dropouts on the Definition 2.

Neat dropouts use the Boost standard

Mason is offering the ISO frameset for £1495 as well as complete bikes: SRAM Force 1 at £3500 and SRAM Rival I at £3195, although it’s happy to build to your own spec too.