Bokeh 3 Shimano. From: £2,850.00

InBoard Disc-Mount

The calliper is mounted on the chain stay, this allows us to use lighter more comfortable seat-stays and gives a flex free mounting for the post-mount components to be welded to. Mounting the brake on the chain stay also keeps it cleanly out of the way of rack and ‘guard stays.

Multiport

Our frames use an adaptable, internal cable routing system. Developed by us to allow your Mason frame to be used with a combination of control systems and adapt and evolve with your requirements and riding styles. We were the first to bring this type of system to a performance steel frame and now use this system across our range. Interchangeable alloy parts allow five options:

1. Full cable outer. 2. Hydraulic Hose. 3. Split outer. 4. Electronic cable [e.g. Shimano Di2]. 5. 2 x Hose/cable or Hose/Dynamo wire 6. Blank.

Taper Head Tubes

Our frames use modern 1-1/8” - 1.5” taper head tubes. Pioneered by composite frames, the taper head tube makes huge sense for metal frames too;

The large overall diameter provides a useful weld area. The fully integrated headset is light and has a very low stack-height. Large 1.5” lower bearing, mated to a tapered carbon fork steerer, spreads the load and gives flex-free braking and instant response to steering input.

Threaded Bottom Brackets

We choose a more traditional 68mm BSA, and T47 threaded standard for our frames because we know that it gives greater durability and creak-free reliability over many miles. The threaded BB is easier to service using standard tools and you are more likely to find a replacement when adventuring far from home. A properly lubricated, threaded BB is also an ideal interface with a metal BB shell.

Hourglass Stays

We tried many shapes before settling on this one, the wall thickness tapers from top to base and the perfect ‘hourglass’ profile gives a sublime, smooth ride with the added spring of steel keeping things lively. We add a custom bend at the base to work with the disc-rotor and calliper.

BoatTail Stays

Unique to MASON. The seat stays flow out of the ovalised top tube and then curve and taper down to meet the chain stays which curve up towards the axle. We call this ‘BoatTail’, a custom bend giving disc-rotor and calliper clearance, helping to avoid chain-slap on the rough stuff and allowing a little compliance to help smooth the ride.

Aluminium Dedacciai Tubing

The entire tubeset was developed in conjunction with Italian, metal tubing gurus Dedacciai. The Definition is constructed from Triple Butted, Hand Selected, custom shaped, 7000 series, Dedacciai Alu tubes and tig welded by hand with beautiful Smooth weld beads. The welds require no after sanding or finishing, so there is no thinning and weakening of the tubes at crucial areas. The frame is fully heat treated, stress relieved and anti-corrosion treated after welding.

Disc Brakes

This frame is designed for disc brakes. They work consistently in all conditions, pull up quicker in the wet, they don't grind your expensive rims into black sludge and in my experience they change the whole riding experience for the better, especially when coupled with modern disc-specific wheels and high-volume tyres. You’ll find yourself riding in a more confident, controlled, fluid and ultimately more efficient way.

Internal Routing

We route the hoses and cables internally where practical, keeping the 'adventure nature' of our bicycles firmly in mind. For smoother runs and a cleaner aesthetic, all control cables, hoses and electronic shift control wires now run through the down tube, via the special BB shell and out through the chainstays, guided by our Mason 'MultiPort' adaptable inserts. Interchangeable Internal routing keeps the control cabling away from road dirt and grime, helps avoid accidental damage, makes cleaning easy, de-clutters your bike and means you can adapt your bike easily to work with various shifting and braking methods. For adventure and endurance riding, internal routing also has the advantage that it is easy to strap frame packs to the frame tubes without being hindered by external cabling and hoses.

Integrated Headset

Integrated, 41.8ø upper, 51.8ø lower, for taper head tube. Both bearings are ‘ACB’, meaning ‘Angular Contact Bearings’. The head-tube seat angle is 45º.

The headset drops into a tapered seat in the head tube and is tensioned using a headset tensioner within the fork steerer. Tensioning the headset centres it on the taper and prevents any play. The larger lower bearing allows a tapered steerer and larger crown. This gives sharper response, helps reduce flex under braking and spreads bearing load.

1x Drivetrain

'1x' is a multi-terrain performance drivetrain with maximum chain security thanks to the narrow-wide chainring and jockey wheels and 'clutched' rear-mech. The range of gears is equivalent to a 2x compact drivetrain, but with the elimination of doubled-up crossover gears. '1x' are lighter, quieter, and more secure.

650B/700C

The Bokeh and Exposure are optimised for large-volume treaded tyres, and are designed for 650B and 700C wheel sizes. Using the smaller 650B wheel means that you can fit a larger-volume treaded tyre for off-road applications, or use a 700C wheel with a tyre of less volume, but with the same rolling radius, when prioritising rolling speed.

We've worked together with HUNT Bike Wheels to develop the tubeless-ready, extra-wide, 650B 'AdventureSport' wheelset: replaceable cartridge bearings; traditional J-bend spokes; easy strip down of the hub system requiring traditional tools only.

Bottle #3

A third bottle cage mount at the base of the down-tube to allow for an additional bottle or tool keg to be fitted. The third bosses are positioned close to the BB to maximise tyre clearance and keep the centre of gravity low. 

FlatMount Brake Calipers

Flat mount disc-brake callipers are lighter, neater, and open up more space within the dropout area for racks and ‘guards. The calliper is mounted to the dropout, allowing us to use a lighter, more comfortable seat-stay.  Up front, the calliper is mounted directly to the fork [via the brake manufacturers adaptor] and offers a cleaner and more minimalist appearance and also provides a compact packaging of the brake caliper.

D-Form Downtube

The DForm down tube is designed by us and tooled exclusively for MASON by Dedacciai in Italy. It is not a simple ‘D’ section and varies in shape from being taller/narrower at the head tube to being wider and lower in section where it meets the BB shell. This shape allows a very wide weld where the tube meets the BB, giving it great stability and ensuring that the weld doesn’t excessively overlap onto the base of the seat tube.

Custom Tubeset

We choose each tube individually, considering the influence that it will have on ride quality and overall performance. We will use a blend of tubing types, custom shapes and bends to help us achieve this goal.

Modern metal frames 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 our properly designed carbon-monocoque forks, the contemporary Aluminium, steel or Titanium frame is a formidable piece of kit.

Switchlever

This model uses SwitchLever Thru-Axles front and rear. This high quality axle system features a removable lever to be used with both axles. Store the lever in the front axle for quick use or remove completely for extra security and a clean, low-profile look.

Optimised Seat tube size

Our smaller frames sizes, from 48 to 58cm use a 31.8mm seat tube and 27.2mm seatpost. Smaller lighter riders don't require large, stiff seatposts and the smaller diameter post and tube help dial out some road-buzz and add long distance comfort.

The larger frame sizes - 60 and 62cm, use oversize 34.9mm seat tubes and 31.6mm seatposts. The larger diameter seat tube adds 'core-stability' to the larger frames and enhances power transfer for larger more powerful riders, with the larger 31.6mm post adding more support.

6 x Accessory Mounts: Bokeh3

The Bokeh is designed for long-distance bikepacking and gravel racing, so the frame and fork are fitted with plenty of bottle and accessory mounts. There are 2 x bottle/accessory mounts on the RangeFinder•AS fork, as well as traditional pannier rack mounts.
Standard frame mount bosses: x2 down tube (top side); x2 down tube (underneath); x2 seat tube; x2 top tube for securing a top tube pack. All eyelet positions are optimised, meaning fluid carrying and bag space are maximised within the frame. The 4th accessory/tool-keg/fluid mount, is now mounted as low as possible under the down-tube, giving space for a larger bottle or bag, whilst still maintaining clearance for larger wheerls/tyres.

RangeFinder•AS

We have developed and tooled for the entirely new ‘RangeFinder•AS’ fork which is custom-tuned for the Exposure and Bokeh3 models. Featuring pannier & ‘rando’ style rack mounts, triple ‘anything-cage’ style accessory mounts, Ø12mm Thru-axle, 160/180mm flat-mount, and huge 27.5 x 2.35” | 700C x 50mm (with a 62mm fender) tyre clearance. The carbon lay-up of this fork has been optimised for this frame’s usage. Additionally featuring sealed internal brake and dynamo light cable routing and our unique Mason 'F-Stop' axle system, with Mason developed SwitchLever axle and replaceable fork inserts.

Thru-BB

'Thru-BB' is unique to MASON aluminium frames. The large 56mmØ presents a large weld area to the base of the down tube and then steps down to the 68mm [road/gravel] & 73mm [MTB] width threaded seats. This step-down provides plenty of space around the outside of the bottom-bracket bearings to allow the control cables and hose to pass through on the way to the chain stays/seat tube and out to the brake, rear mech, dropper-post etc.

IMPORTANT: This BB shell design requires the use of a bottom bracket with a 24mm or 30mm 'sleeved' axle like most Shimano or SRAM DUB, because the hose/cables/control wires run through the shell and under the axle. DO NOT use a bottom bracket type without a sleeve. Campagnolo sleeves are available on the site HERE. Please contact us if you would like advice on compatible cranksets/BB types.

160/180 Flat-Mount

Our HotShoe2 [Macro & InSearchOf] and RangeFinder [SLR, Exposure, Bokeh3] forks, were amongst the first carbon forks to have Flat-Mount compatability for 160 and 180mm rotors. This allows for controllable, dependable stopping power when riding loaded and in steep, rough conditions.