Exposure GRX Di2 £4,850.00

Size

1x or 2x

  1. 2x
  2. 1x

Colour

  1. FilterYellow
  2. OpticGreen
  3. DiffuserBlack Metallic

Exposure GRX Di2

The new MASON Exposure is a steel reinterpretation of our award-winning Bokeh model, designed in collaboration with one of the most skilled bicycle frame builders in the world - Cicli Barco.

The Exposure is far more than a ‘Steel Bokeh’ though. Designed with capacity for larger 650B x 58mm [2.35”] / 700c x 50mm tyres, full fenders, and more carrying capacity with multiple attachment locations for accessories, racks, and extra fluid for extended rides.

This lovingly crafted Exposure frameset is paired with GRX Di2 - Shimano's fully electronic adventure-riding specific groupset. Designed with a range of unique performance features and ergonomics developed over several years to make adventure riding as fast and comfortable as possible.

Our builds are available with 1×11 or 2×11 cranksets, both using adventure/bikepacking tuned ratios, and the latest clutched RX-817 Di2 derailleurs to match.

More Exposure Frameset details here.

Features

  • 1X: Lightweight M8000 11-42 Cassette / 2X: R800 11-34 Cassette
  • Rear rack bosses.
  • 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.
  • 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.
  • 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.
  • European-made, exclusively custom shaped and formed, phosphate anti-corrosion treated Dedacciai Zero/Zero Uno tube set.
  • 100% Italian TIG-welded/silver-brazed frame manufacturing, wet-painting, and finishing.
  • 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.
  • Full Shimano GRX 815, 11speed, electronic Di2 groupset.
  • 1X: £4850, 2X: £5050

Details

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.

Sizing 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.

MTB, TRAIL/TRAVEL - RAW: 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 is 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.

Custom Mason X Dedacciai Tubing

Almost the entire tubeset was developed in conjunction with Italian tube gurus Dedacciai, using their new 'ZERO', fine grain, micro-alloyed, progressive butted steel tubing. We work very closely with them to develop our Alu, Ti and steel tubesets for Bokeh, BokehTi, Definition, ISO, RAW and Exposure models.

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. The cables, hoses and electronic shift control wires run through the frame tubes, 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.

T47

This frame features a stainless-steel 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.

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. 

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.

8x Bottle / Accessory Mounts

The Exposure is designed for long-distance and multi-month adventure touring, so all Exposure framesets have a plethora 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: x4 down tube (top side); x3 down tube (underneath); x3 seat tube; x2 top tube for securing a top tube pack; x2 seat stays (both sides). Designed for maximum adaptability and adjustment when using larger or full-frame bags.

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 20kg. Follow manufacturers installation and loading instructions.

Rando Racks: Max load capacity of 10kg. Follow manufacturers installation and loading instructions.

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 Deda Classic 44mm Press-in Headset.
Colours FilterYellow. OpticGreen. DiffuserBlack.
Bike Weight 54cm - approx. 9.2kg.
Sizes 48, 50, 52, 54, 56, 58, 60, 62.
Shifting Shimano GRX-815 Di2 Shifting.
Chainset Shimano GRX-810 1x (42T) / 2x (48/31)
Cassette Shimano M8000 11-42. / CS800 11-34
Chain Shimano HG701 11 Spd.
Braking Shimano GRX-810 Hydro Calipers.
Tyres Choice of Schwalbe, Panaracer, WTB.
Wheels HUNT Four Season Gravel Disc X-Wide / Mason X HUNT 650B AdventureSport Disc. Other models available.
Handlebar Deda Gravel100
Clamp MASON Macro alloy ultralight.
Seatpost MASON Penta carbon, microadjust.
Saddle Fizik Terra Argo X3.
Bar Tape Mason Contact Tape.
Stem DEDA Zero100.