Your Exposure Shimano
THE LATEST EVOLUTION OF OUR UNIQUE MASON EXPOSURE, WITH CONFIGURABLE SHIMANO BUILD OPTIONS
Our Italian made, Dedacciai Steel, bikepacking and adventure bicycle. Designed with larger clearances and more relaxed geometry, it is highly adaptable with multiple load and accessory carrying configurations. "Masterpiece is a pretty big word to throw into a bike review, but I’m as comfortable and excited about using it here..." - Bike Perfect 2023.
This lovingly crafted bicycle is developed for fast, long-distance, extended adventure touring over very variable and unpredictable terrain. Designed with capacity for 650b x 58mm [2.35”] and 700c x 50mm tyres.
The custom-shaped, progressively butted, phosphate-coated Dedacciai Zero Uno tube set with Reynolds 631, CNC machined by BEAR, 44mm head tube, is shaped exclusively for the Exposure frame. It is engineered by Dedacciai for 'Long Range' and offers class-leading toughness and weight, combined with engaging pedalling feel, ride quality and efficiency.
Paired with a brand new MASON full-carbon fork - the RangeFinder AS ['AS' for AdventureSport] - which is tuned for all surface riding conditions. The Rangefinder AS features a full set of molded-in eyelets, and is designed to be fitted with a front rack or rando-style bag support, along with accessory cages and internally routed dynamo light.
Features
- RangeFinder AS carbon fork which is custom-tuned for the Exposure. Features pannier & ‘rando’ style rack mounts, triple accessory mounts, Ø12mm Thru-axle, 160/180mm flat-mount, and 27.5 x 2.35" || 700 X 50mm tyre clearance.
- Stainless-steel T47 BB Shell, allows hose and cables to be internally routed and exit through chainstays to the rear mech and flat-mount caliper.
- Available with a choice of the best 650B and 700C tyres from Panaracer, WTB, Rene Herse and Schwalbe.
- A choice of finishing kit from Deda and Ritchey
- Carbon MASON Penta microadjust seatpost and MASON Macro seatclamp.
- Available with a choice of HUNT, DT Swiss and Campagnolo wheelsets in 700c or 650b. Other options available on request.
- Dedicated internal dynamo routing through top tube and fork. Light-mount on fork crown.
- Select From: Shimano GRX mechanical 11 speed / GRX Di2 11 speed / GRX mechanical 12 speed / 1x or 2x
- This bike can be fitted with the Mason Luminance Upgrade. The ultimate dynamo + lighting set-up for all-terrain and multi-surface adventures. See 'Accessories + Upgrades' for details.
- CNC machined brake mount and dropouts, developed in conjunction with our Italian manufacturing partners. Eyebolts can be fitted for fender mounting on dropouts, or removed and replaced with a stainless grub screw for a clean aesthetic.
- Bottle cage/Accessory cage boss placements as standard: x4 down tube (top side); x3 down tube (underneath); x3 seat tube; x2 top tube for secure top tube pack mount; x2 seat stays (both sides).
- Clearance for: 27.5” x 2.35” | 650B x 55mm (with 62mm fender) | 700C x 50mm (with 62mm fender) tyres.
- 100% Italian TIG-welded/silver-brazed frame manufacturing, wet-painting, and finishing.
- European-made, exclusively custom shaped and formed, phosphate anti-corrosion treated Dedacciai Zero/Zero Uno tube set.
- UK-made, Reynolds 631 steel, BEAR 44/46mm head tube for semi-integrated headset. Very tough, internally butted, and externally ring-reinforced. Suitable for all high-quality press-fit headsets.
Details
A DECADE OF DETAILS
With 10 years of perfecting & optimising every detail in our MASON range, along with over 25 years of metal frame design experience, we feel confident that all the features you'll ever need, along with some that you hadn't thought of, are lovingly and meticulously included in your frameset and finished bicycle.
We actively support some of the most experienced adventure and endurance riders, listen to our customers and work closely with experienced and passionate frame makers. Because of this rich mix, we are able to offer what we believe to be the most carefully designed, obsessively detailed and lovingly made framesets and bicycles in the world.
MASON MAKERS
BUILT WITH CARE AND ABSOLUTE ATTENTION TO DETAIL
We’re proud to collaborate with independent, bespoke frame makers who are at the pinnacle of their craft. This is something we care about a lot and we feel honoured to be working with small makers in Italy for most of our models, some who have been dedicated to the art of metal frame production for nearly 75 years.
Technical info
Select size
|
Dimensions (mm unless specified) |
||
|---|---|---|
| A > | SEAT TUBE C/T | 480 |
| B > | SEAT TUBE C/C | 432.3 |
| C > | BB DROP | 77 |
| D > | REAR CENTRE | 435 |
| E > | TT EFFECTIVE | 515.9 |
| F > | TT ACTUAL | 497.8 |
| G > | STACK | 536.1 |
| H > | REACH | 359.9 |
| I > | STAND-OVER | 721 [650 x 47] |
| J > | OFFSET | 50 |
| K > | TRAIL Trail data for more wheel/tyres in full geo. chart (where applicable) |
74.7 [650 x 47] |
| L > | FORK CROWN HEIGHT | 398 |
| M > | HEAD ANGLE | 69.5 |
| N > | HEAD TUBE LENGTH | 100 |
| O > | SEAT TUBE ANGLE | 74.0 |
| P > | WHEELBASE | 1013 |
| Q > | HANDLEBAR (OUTSIDE DIMENSION) | 40 |
|
Dimensions (mm unless specified) |
||
|---|---|---|
| A > | SEAT TUBE C/T | 500 |
| B > | SEAT TUBE C/C | 452.5 |
| C > | BB DROP | 77 |
| D > | REAR CENTRE | 435 |
| E > | TT EFFECTIVE | 520 |
| F > | TT ACTUAL | 502.4 |
| G > | STACK | 550.2 |
| H > | REACH | 360 |
| I > | STAND-OVER | 747 [650 x 55] |
| J > | OFFSET | 50 |
| K > | TRAIL Trail data for more wheel/tyres in full geo. chart (where applicable) |
77.7 [650 x 55] |
| L > | FORK CROWN HEIGHT | 398 |
| M > | HEAD ANGLE | 69.5 |
| N > | HEAD TUBE LENGTH | 115 |
| O > | SEAT TUBE ANGLE | 74.0 |
| P > | WHEELBASE | 1018.4 |
| Q > | HANDLEBAR (OUTSIDE DIMENSION) | 40 |
|
Dimensions (mm unless specified) |
||
|---|---|---|
| A > | SEAT TUBE C/T | 520 |
| B > | SEAT TUBE C/C | 472.7 |
| C > | BB DROP | 77 |
| D > | REAR CENTRE | 435 |
| E > | TT EFFECTIVE | 535 |
| F > | TT ACTUAL | 517.6 |
| G > | STACK | 566.2 |
| H > | REACH | 370.6 |
| I > | STAND-OVER | 767 [650 x 55] |
| J > | OFFSET | 50 |
| K > | TRAIL Trail data for more wheel/tyres in full geo. chart (where applicable) |
74.4 [650 x 55] |
| L > | FORK CROWN HEIGHT | 398 |
| M > | HEAD ANGLE | 70.0 |
| N > | HEAD TUBE LENGTH | 130 |
| O > | SEAT TUBE ANGLE | 74.0 |
| P > | WHEELBASE | 1030 |
| Q > | HANDLEBAR (OUTSIDE DIMENSION) | 42 |
|
Dimensions (mm unless specified) |
||
|---|---|---|
| A > | SEAT TUBE C/T | 540 |
| B > | SEAT TUBE C/C | 493.5 |
| C > | BB DROP | 75 |
| D > | REAR CENTRE | 435 |
| E > | TT EFFECTIVE | 553.3 |
| F > | TT ACTUAL | 534.9 |
| G > | STACK | 578.3 |
| H > | REACH | 375 |
| I > | STAND-OVER | 787 [650 x 55] |
| J > | OFFSET | 50 |
| K > | TRAIL Trail data for more wheel/tyres in full geo. chart (where applicable) |
74.4 [650 x 55] |
| L > | FORK CROWN HEIGHT | 398 |
| M > | HEAD ANGLE | 70.0 |
| N > | HEAD TUBE LENGTH | 145 |
| O > | SEAT TUBE ANGLE | 73.0 |
| P > | WHEELBASE | 1039.9 |
| Q > | HANDLEBAR (OUTSIDE DIMENSION) | 44 |
|
Dimensions (mm unless specified) |
||
|---|---|---|
| A > | SEAT TUBE C/T | 560 |
| B > | SEAT TUBE C/C | 513.4 |
| C > | BB DROP | 75 |
| D > | REAR CENTRE | 435 |
| E > | TT EFFECTIVE | 561.5 |
| F > | TT ACTUAL | 544 |
| G > | STACK | 589.8 |
| H > | REACH | 379.9 |
| I > | STAND-OVER | 803 [650 x 55] |
| J > | OFFSET | 50 |
| K > | TRAIL Trail data for more wheel/tyres in full geo. chart (where applicable) |
71.1 [650 x 55] |
| L > | FORK CROWN HEIGHT | 398 |
| M > | HEAD ANGLE | 70.5 |
| N > | HEAD TUBE LENGTH | 155 |
| O > | SEAT TUBE ANGLE | 73.0 |
| P > | WHEELBASE | 1043.2 |
| Q > | HANDLEBAR (OUTSIDE DIMENSION) | 44 |
|
Dimensions (mm unless specified) |
||
|---|---|---|
| A > | SEAT TUBE C/T | 580 |
| B > | SEAT TUBE C/C | 533.7 |
| C > | BB DROP | 73 |
| D > | REAR CENTRE | 435 |
| E > | TT EFFECTIVE | 584.2 |
| F > | TT ACTUAL | 566.8 |
| G > | STACK | 604 |
| H > | REACH | 392.9 |
| I > | STAND-OVER | 822 [650 x 55] |
| J > | OFFSET | 50 |
| K > | TRAIL Trail data for more wheel/tyres in full geo. chart (where applicable) |
67.8 [650 x 55] |
| L > | FORK CROWN HEIGHT | 398 |
| M > | HEAD ANGLE | 71 |
| N > | HEAD TUBE LENGTH | 170 |
| O > | SEAT TUBE ANGLE | 72.5 |
| P > | WHEELBASE | 1057.5 |
| Q > | HANDLEBAR (OUTSIDE DIMENSION) | 46 |
|
Dimensions (mm unless specified) |
||
|---|---|---|
| A > | SEAT TUBE C/T | 600 |
| B > | SEAT TUBE C/C | 553.6 |
| C > | BB DROP | 73 |
| D > | REAR CENTRE | 435 |
| E > | TT EFFECTIVE | 594.6 |
| F > | TT ACTUAL | 576.2 |
| G > | STACK | 627.7 |
| H > | REACH | 395.9 |
| I > | STAND-OVER | 844 [650 x 55] |
| J > | OFFSET | 50 |
| K > | TRAIL Trail data for more wheel/tyres in full geo. chart (where applicable) |
67.8 [650 x 55] |
| L > | FORK CROWN HEIGHT | 398 |
| M > | HEAD ANGLE | 71 |
| N > | HEAD TUBE LENGTH | 195 |
| O > | SEAT TUBE ANGLE | 72.5 |
| P > | WHEELBASE | 1068.5 |
| Q > | HANDLEBAR (OUTSIDE DIMENSION) | 46 |
|
Dimensions (mm unless specified) |
||
|---|---|---|
| A > | SEAT TUBE C/T | 620 |
| B > | SEAT TUBE C/C | 573.9 |
| C > | BB DROP | 73 |
| D > | REAR CENTRE | 435 |
| E > | TT EFFECTIVE | 607.3 |
| F > | TT ACTUAL | 589.3 |
| G > | STACK | 644 |
| H > | REACH | 403.6 |
| I > | STAND-OVER | 860 [650 x 55] |
| J > | OFFSET | 50 |
| K > | TRAIL Trail data for more wheel/tyres in full geo. chart (where applicable) |
64.6 [650 x 55] |
| L > | FORK CROWN HEIGHT | 398 |
| M > | HEAD ANGLE | 71.5 |
| N > | HEAD TUBE LENGTH | 210 |
| O > | SEAT TUBE ANGLE | 72.5 |
| P > | WHEELBASE | 1076.2 |
| Q > | HANDLEBAR (OUTSIDE DIMENSION) | 46 |
This page gives you some guidelines based on rider height, but these are only a starting point for a proper bike fitting. There are of course many other factors to consider when choosing the right size for you and sizing advice will vary depending on your choice of model from the Mason range and the way that you intend to ride it. We're always here to help of course and would always recommend a professional bike fitting and visiting us for a ride on the Mason Cycles riverside gravel/country lanes test-loop if you can. There is further advice, based on specific models, below the height chart.
Fitting a bike to a rider is an important process, this information is a start to the process but it’s not really possible to give 100% accurate fitting instructions online.
Humans are odd shapes, each person’s physical dimensions: arm, torso, femur length, level of flexibility, skill level and intended model usage are very different. This means that there will invariably be different frame size requirements, even for people of the same height and inseam.
SIZING ADVICE BASED ON MASON MODELS
ROAD, ALL-ROAD & GRAVEL - Aspect | Resolution | Definition | SLR | BokehTi | Bokeh | Exposure: Size range is 48cm to 62cm depending on specific model. The chart dimensions show the extremes of useable frame size based on height and the rider size range is very similar for all our frames with 6 or 8 standard sizes.
ULTIMATE ADVENTURE - InSearchOf: Size range is 42cm to 58cm [5 sizes]. As a start point, we would recommend selecting one size down from your normal 'road' frame size. For example, if you would normally ride a 54cm then a 50cm InSearchOf is probably best for you.
ADVENTURE HARDTAIL - RAW | Macro: Size range is Sml to XL [4 sizes]. With the advent of modern, more progressive mountain bike geometry, the sizing process is even more fluid. The Mason RAW and Macro are no different: seat tube lengths are kept deliberately low so riders have a certain amount of flexibility in choosing size based on their preferred reach, wheelbase, handling characteristics and intended use. For instance, for high speed and loaded up stability you may prefer a larger frame that will also provide more pack space in the front triangle. Or, if you are spending most of your time on twisty woodland singletrack, you’d benefit from the shorter wheelbase and extra response of the smaller frame.
We are experienced in sizing and geometry, so of course we will be on the end of the phone or email to help and advise, but we would always recommend having a proper bike fit done before committing, especially if you feel like you may be between sizes. If you do fall between our frame sizes, it’s probably best to go with the smaller size. It’s easier to make a smaller frame fit a little larger than vice versa.
CONFIGURATION: With all models, you can use our drop down menus to configure your finishing kit to suit your needs, including which brake lever operates front/rear wheel and for MTB we’re happy to cut down the handlebar to your desired width.
Please email us here or call 01273 463000 if you have further requirements that you would like to discuss, we are always happy to help.
44MM HEADSET
A straight 44mm internal diameter head tube uses the EC44/ZS44 press fit headset standard which allows compatibility with all current fork steerer tube standards as well as angle adjust headsets.
44mm RING-REINFORCED HEAD TUBES
This frameset features a UK made Reynolds 631 head tube, CNC-machined by BEAR Frame Supplies.
The large overall diameter provides a useful weld area, with ‘Ring-Reinforcement’ top and bottom for strength and tapering down in the middle to reduce weight.
T47
This frame features a T47 BB Shell which allows the brake hose and gear cables to be 100% internally routed through the frame tubing and exit through the chainstays to the rear mech and flat-mount brake caliper.
CUSTOM MASON X DEDACCIAI TUBING: ZERO/ZERO UNO
Almost the entire tubeset was developed in conjunction with Italian tube gurus Dedacciai, using their new 'ZERO/ZERO UNO', fine grain, micro-alloyed, progressive butted steel tubing. We work very closely with them to develop our model-specific Alu, Ti and steel tubesets for Bokeh, BokehTi, Definition, ISO, RAW, Exposure and SLR.
Mason X Barco
MASON is renowned for designing and producing award-winning bicycle frames in conjunction with the world’s finest frame builders, drawing on their expertise to create a finely tuned bicycle from both manufacturing and riding perspectives. This model is fabricated in Italy by our friends at Cicli Barco. Like MASON, they are a family business and are amongst the most highly skilled frame fabricators in the world, renowned in the global frame building industry. What has brought us together with Cicli Barco is their highly personal approach to frame building and business, backed up by perfect fabrication.
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.
F-Stop Axle System
The Mason F-Stop Insert System was developed for our exclusive Aperture2 and RangeFinder forks, used on our Definition, Resolution, Aspect, Exposure and SLR bicycles.
The axle uses our 12mm Thru-Axle 'SwitchLever' which features a removable CNCd lever key, fitted with a 6mm hex key. You can leave the key in and it's there for easy wheel removal, or take it off and leave it in your pocket for a clean dropout.
The Aperture2 and Rangefinder forks also feature removable tip inserts meaning that all wearing parts are replaceable, vastly extending the life of your Mason bicycle.
27.2 Seat Post
Our oversize seat tubes don't house oversize seat posts. The large diameter seat tube helps the 'core-stability' of the frame but large, stiff seat posts don't help rider comfort. A 27.2mm post helps to dial out road-buzz and the smoother ride means you stay fresher for longer.
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.
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.
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.
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.
Essential Dimensions: Exposure
BRAKING
Rotor Size: The fork can take a 160 or 180mm rotor. 160mm is the maximum recommended diameter for the rear and the native rotor size is 140mm.
Calliper Type: These frames are designed for flat-mount calipers. It's possible to fit post-mount calipers front and rear with the use of a flat > post-mount adapter.
Exposure Flat-Mount Mounting Bolt Lengths: FRONT - 15mm. REAR - SRAM: 17mm. Shimano: 23mm.
NOTE: Bolt lengths for mounting Flat-Mount brake calipers to our frames vary because of the different dropout designs and materials used across our range.
We always recommend using genuine hardware and consulting us directly using the 'Technical' dropdown, or using a qualified cycle mechanic if in doubt.
NOTE: This frame is compatible with most modern disc-brake systems but may not be suitable for ALL brake callipers. Please check clearance before purchasing your braking system.
CHAINRING SIZES
Max 1x chainring size: 40T.
Max 2x chainring size: 31/48T.
Frameset Only Customers: Contact us if you would like further advice on fitting your specific chainset.
SEATSTAY ACCESSORY MOUNTS
Use 2-bolt cages and accessories only. Check rotation of wheel before riding. Ensure that any mounted accessories do not interfere with the wheels, tyre or spokes.
Max load capacity 1kg per side. Follow manufacturers installation and loading instructions.
WHEELS + AXLE SPACING
Ø12mm Thru-axle Front / Ø12mm Thru-axle rear.
Front axle spacing: 100mm. Rear axle spacing: 142mm.
Axle length/pitch: Exposure: Front - 120mm/1.5P. Rear - 166mm/1.5P.
TYRES
The below are guides only. Fitted width may vary depending on manufacturer and rim width. Please check true dimensions of chosen components to be sure.
Exposure:
Max tyre widths with 'guards:
700C x 45mm | 650B x 55mm.
Max tyre widths without 'guards:
700C x 50mm | 650B x 59mm | 27.5 x 2.35".
SEAT POST
Exposure: 27.2mm.
SEAT CLAMP
Exposure: 31.8mm.
FRONT MECH
Exposure: 31.8mm
BB TYPE
T47 x 68mm
RANGEFINDER FORK
Headset type: Integrated, 41.8Ø upper, 51.8Ø lower, for taper head tube. Angular Contact Bearings. The head-tube internal seat angle is 45º. The lower crown race angle is 45º. Note: New 'CarbonRace' technology used with RangeFinder forks means that the use of the lower crown race supplied with headsets is not necessary. Lower bearing seats directly on carbon taper seat.
Stack-washer maximum: 40mm below stem is max. recommended for carbon steerer. Warranty is void above this dimension.
Dimensions: Crown height - 398mm. Offset - 50mm.
Mounting Bolt Torque: 4Nm.
Accessory Cages: Max load capacity 6kg per side. Follow manufacturers installation and loading instructions.
Pannier Racks: Max total load capacity of 10kg. Follow manufacturers installation and loading instructions.
Rando Racks: Max load capacity of 2.5kg. Follow manufacturers installation and loading instructions.
Total Combined Load Capacity: 15kg.
Specifications
Our frame sets deserve the best components, so we put a great deal of thought into the mix of parts used for each bike build. Bars, stem and crankset are sized to match frame size choice. See Geometry chart for component sizing.
| Frame | Dedacciai Zero / Uno custom-shaped performance steel. |
| Fork | Mason Rangefinder AS custom tuned, full carbon, thru-axle fork with accessory and rack-mounts. |
| Headset | Select From: Deda & Chris King. |
| Colours | FilterYellow. OpticGreen. DiffuserBlack. |
| Bike Weight | 54cm GRX 1x mechanical - approx. 9.4kg. |
| Sizes | 48, 50, 52, 54, 56, 58, 60, 62. |
| Chainset | 2x 48/31. 1x 42. Select From: GRX 820 12spd Mechanical / GRX 810 11spd Mechanical / GRX-815 Di2 11spd / GRX-825 Di2 12spd - As Selected. |
| Shifting | GRX 820 12spd Mechanical / GRX 810 11spd Mechanical / GRX-815 Di2 11spd / GRX-825 Di2 12spd - As Selected. |
| Cassette | 2x 11-34. 1x 11-42. GRX 820 12spd Mechanical / GRX 810 11spd Mechanical / GRX-815 Di2 11spd / GRX-825 Di2 12spd - As Selected. Alternative ratios available on request. |
| Chain | Shimano - As Selected. Other options available on request. |
| Wheels | Select From: HUNT / DT Swiss / Campagnolo. Other options available on request. |
| Tyres | 650b & 700c. Select From: Rene Herse / Schwalbe / Continental / Vittoria/ WTB. Other options available on request. |
| Brakes | SHIMANO GRX 820 / GRX 810 / GRX-815 / GRX-825 - As Selected. Other options available on request. |
| Saddle | Choice of Fizik options. Other brands available on request. |
| Seatpost | MASON Penta carbon, microadjust. |
| Clamp | MASON Macro alloy. |
| Handlebar | Choice of Deda or Ritchey options. Other brands available on request. |
| Bar Tape | MASON Contact Tape. |
| Stem | Select Various Lengths. Choose From: DEDA Superzero or Zero2. |