Motobecane Boris Fatbike X9 SRAM X9

2026 MountainFat bike

Last known price: $3,999

Prices shown first for United States
Suspension: Rigid
Wheels: 26″
Drivetrain: 1 × 10 22t / 11–36t
Gear range: 327%
Frame: Aluminum
Brakes: Mechanical disc

Sizes

Size guide

The manufacturer did not publish rider heights for these sizes.

Components

12 of 14 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

ALLOY 6061 FRAME, W/DISC MOUNT, TIG WELD, replaceable rear derailleur hanger, H2O bosses, 170mm QR Rear Not identified

Suspension

2 parts

Fork

26" 25.4x28.6x30x250L Straight blade CRMO 1 1/8 W/DISC MOUNT ONLY + Trifecta Braze-ons Not identified
Rear shock

None

Drivetrain

6 parts

Bottom bracket
- SRAM
Cassette
- SRAM PG-1030 10 speeds
PG-1030
Chain
- KMC X10 10 speeds
X-10CL-566R
Crankset
- SRAM X5 10 speeds 22t
Rear derailleur
- SRAM X9
FD-X7RD-X9
Shifters
- SRAM SL-700 10-Speed Trigger 10 speeds
SL-700PG-1030

Brakes

2 parts

Brake levers
- SRAM FR-5
FR-5
Brakes
- Avid

Wheels and tires

2 parts

Cockpit and contact points

2 parts

Handlebar
- WTB
Headset
- VP
VP-A42EM-1D

Sizes and geometry

4 sizes Open in the geometry plotter

Complete rider-height ranges are not published for these sizes. You can still explore the geometry below.

Size 17"

Table

Geometry diagram unavailable

The drawing needs reach, stack and head tube length, which the manufacturer did not publish. Available facts remain in the table.

Size

Complete manufacturer geometry table 4 published sizes

Complete manufacturer geometry by size
Measurement
Top tube lengthmm	583	602	622	640
Seat tube lengthmm	381	432	483	533
Head tube angle	69.5°	70°	70°	70°
Seat tube angle	73°	73°	73°	73°
Chainstay lengthmm	467	467	467	467
Wheelbasemm	1093	1117	1144	1170
Front centermm	628	652	679	705
Bottom bracket dropmm	33	33	33	33
Bottom bracket heightmm	310	310	310	310
Standover heightmm	701	742	779	819
Fork rakemm	51	51	51	51

Not published by the manufacturer: Reach, Stack, Head tube length, Trail, Stack/reach ratio, Front travel, Rear travel, Crank length, Handlebar width, Stem length, Stem angle, Seatpost length and Dropper post travel.

Specifications

Frame and fork

Intended fit: Unisex
Frame material: Aluminum
Fork material: Steel

Suspension

Suspension configuration: Rigid

Drivetrain

Derived by Bikelake

Front chainrings: 1
Smallest chainring: 22
Largest chainring: 22
Rear sprockets: 10
Smallest sprocket: 11
Largest sprocket: 36
Lowest gear: 15.9 in
Highest gear: 52.0 in

Wheels and brakes

Wheel configuration: Same size
Brake type: Mechanical disc

Fit and controls

Shifting: Mechanical

Additional specifications

Tire width: 4″
Travel: Front: Additional specification: Not available: Yes
Rear: Additional specification: Not available: Yes
Wheel material: Aluminum
Wheel size: 26″

Gearing

Estimated speeds at 80 rpm

Lowest gear: 6.1 km/h
Highest gear: 19.9 km/h

Total gear range 327%

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.