Mason Exposure Shimano

Name: Mason Exposure Shimano
Brand: Mason

2025 RoadGravel Manufacturer page

Price: Not published

Prices shown first for United States
United Kingdom: £3,750 Last known price
Suspension: Rigid
Wheels: 650b
Drivetrain: 2 × 12 31–48t / 11–34t
Gear range: 479%
Frame: Steel
Brakes: Hydraulic disc

Rider height by size (cm)

Size guide

48cm 151–160
50cm 157–168
52cm 163–172
54cm 170–180
56cm 175–185
58cm 180–188
60cm 185–193
62cm 188–198

Components

8 of 15 identified

Parts found in a manufacturer catalog show their brand, model and key numbers, and the steps show how precisely they are identified: brand, series, model, or the exact product. The info button has every detail and the text the manufacturer published.

Frame and fork

1 part

Frame

Dedacciai Zero / Uno custom-shaped performance steel. Not identified

Suspension

1 part

Fork

Mason Rangefinder AS custom tuned, full carbon, thru-axle fork with accessory and rack-mounts. Not identified

Drivetrain

5 parts

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. Not identified

GRX-815GRX-825
Chain
- Shimano
Crankset

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. Not identified

GRX-815GRX-825
Rear derailleur

GRX 820 12spd Mechanical / GRX 810 11spd Mechanical / GRX-815 Di2 11spd / GRX-825 Di2 12spd - As Selected. Not identified

GRX-815GRX-825
Shifters

GRX 820 12spd Mechanical / GRX 810 11spd Mechanical / GRX-815 Di2 11spd / GRX-825 Di2 12spd - As Selected. Not identified

GRX-815GRX-825

Brakes

1 part

Brakes
- Shimano GRX
GRX-815GRX-825

Wheels and tires

2 parts

Cockpit and contact points

5 parts

Handlebar
- Deda
Headset
- Deda
Saddle
- Fizik
Seatpost

MASON Penta carbon, microadjust. Not identified
Stem
- Deda

Sizes and geometry

8 sizes Open in the geometry plotter

Enter your height to highlight matching ranges.

Size 54cm

Table

Reach 375mm

Stack 578mm

Wheelbase 1040mm

Head angle 70.0°

Seat angle 73.0°

Every size is drawn to the same scale, in millimeters. Explanatory schematic on an assumed 650b wheel; exact published values are in the table below.

Size Reported by the manufacturer

Complete manufacturer geometry table 8 published sizes

Complete manufacturer geometry by size
Measurement
Frame
Reachmm	359.9	360	370.6	375	379.9	392.9	395.9	403.6
Stackmm	536.1	550.2	566.2	578.3	589.8	604	627.7	644
Top tube lengthmm	515.9	520	535	553.3	561.5	584.2	594.6	607.3
Seat tube lengthmm	480	500	520	540	560	580	600	620
Head tube lengthmm	100	115	130	145	155	170	195	210
Head tube angle	69.5°	69.5°	70°	70°	70.5°	71°	71°	71.5°
Seat tube angle	74°	74°	74°	73°	73°	72.5°	72.5°	72.5°
Chainstay lengthmm	435	435	435	435	435	435	435	435
Wheelbasemm	1013	1018.4	1030	1039.9	1043.2	1057.5	1068.5	1076.2
Front centermm	590	595.3	606.8	616	619.5	632.9	643.9	651.5
Bottom bracket dropmm	77	77	77	75	75	73	73	73
Standover heightmm	721	747	767	787	803	822	844	860
Fork rakemm	50	50	50	50	50	50	50	50
Trailmm	70	70	67	67	64	61	61	58
Stack/reach ratio	1.49	1.53	1.53	1.54	1.55	1.54	1.59	1.60
Suspension and parts
Crank lengthmm	165	165	170	170	172.5	172.5	175	175
Stem lengthmm	70	80	90	90	100	100	110	110

Not published by the manufacturer: Bottom bracket height, Front travel, Rear travel, Handlebar width, Stem angle, Seatpost length and Dropper post travel.

Specifications

Frame and fork

Intended fit: Unisex
Frame material: Steel
Fork material: Carbon
Frame weight: 0.52 kg

1.1 lb

Suspension

Suspension configuration: Rigid

Drivetrain

Derived by Bikelake

Front chainrings: 2
Smallest chainring: 31
Largest chainring: 48
Rear sprockets: 12
Smallest sprocket: 11
Largest sprocket: 34
Lowest gear: 25.1 in
Highest gear: 120.0 in

Wheels and brakes

Wheel configuration: Same size
Brake type: Hydraulic disc

Fit and controls

Seatpost: Rigid seatpost
Shifting: Electronic

Additional specifications

Tire clearance: Maximum tire width: 55c; Additional specification: Wheel kind: 27.5, Maximum tire width: 50c; Additional specification: Wheel kind: 700
Wheel material: Aluminum
Wheel size: 650b

Technical analysis

3 measures

How these figures sit among bicycles of the same class and model year. Context, not a ranking.

Lowest gear

25.1 gear inches

This value is within the central range for this class.

Cohort: Road / Gravel Model year: 2025
Sample: 1,536 bicycles with this information
Coverage: 76.6% of the class

Highest gear

120.0 gear inches

This value is within the central range for this class.

Cohort: Road / Gravel Model year: 2025
Sample: 1,536 bicycles with this information
Coverage: 76.6% of the class

Shifting

Electronic

688 of 1,999 bicycles with this information use electronic shifting.

Cohort: Road / Gravel Model year: 2025
Sample: 1,999 bicycles with this information
Coverage: 99.7% of the class

Gearing

Estimated speeds at 80 rpm

Lowest gear: 9.6 km/h
Highest gear: 46.0 km/h

Total gear range 479%

Technical details and class reference

These speeds describe the gearing at the selected cadence, not how fast you can ride.
Calculated from published gear-inch values and their wheel-size assumptions.
These gearing values describe the bicycle, not a selected frame size.
A 100% range means one ratio; 500% means the highest ratio is five times the lowest.
For e-bikes, motor assistance cutoff is not represented.

Gear-inch range

Lower gear-inch values travel less distance per pedal revolution; higher values travel farther.

This bicycle: 25.1–120.0 gear inches
Class reference (p10–p90): 22.8–126.6 gear inches; The band runs from p10 for the lowest gear to p90 for the highest gear.

Cohort: Road / Gravel Model year: 2025
Lowest gear: 1536 bicycles with this information, 76.6% of the class
Highest gear: 1536 bicycles with this information, 76.6% of the class

Lineup changes

The published facts that differ across this family's builds and from the same model a year earlier. Missing information never counts as zero.

Differences across 2025 builds
Specification	This bicycle Mason Exposure Shimano	Mason Exposure Campagnolo	Mason Exposure SRAM
Drivetrain
Front chainrings	2	Not informed	2
Smallest chainring	31	Not informed	35
Largest chainring	48	Not informed	48
Rear sprockets	12	13	12
Smallest sprocket	11	Not informed	10
Largest sprocket	34	Not informed	36
Lowest gear	25.1 in	Not informed	26.7 in
Highest gear	120.0 in	Not informed	132.0 in
Cockpit
Shifting	Electronic	Mechanical	Electronic
Other specifications
Tire clearance	Maximum tire width: 55c; Additional specification: Wheel kind: 27.5, Maximum tire width: 50c; Additional specification: Wheel kind: 700	Maximum tire width: 50c; Additional specification: Wheel kind: 700	Maximum tire width: 55c; Additional specification: Wheel kind: 27.5, Maximum tire width: 50c; Additional specification: Wheel kind: 700