Polygon Tambora G8X

2026 RoadGravel Manufacturer page

Last known price: $2,999

Prices shown first for United States
Suspension: Rigid
Wheels: 700c
Drivetrain: 1 × 12 40t / 10–44t
Gear range: 440%
Frame: Carbon
Brakes: Hydraulic disc

Rider height by size (cm)

Size guide

SM 150–164
MD 162–176
LG 174–189
XL 187–195

Components

13 of 20 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

carbon Not identified

Suspension

1 part

Fork

CARBON RIGID Not identified

Drivetrain

6 parts

Brakes

3 parts

Wheels and tires

5 parts

Front hub
- Novatec
Rear hub
- Novatec
Rims

CARBON FV H: 28 622x24 24H FOR TYRE 622-35/68 TLR Not identified
Spokes

F: STAINLESS DOUBLE BUTTED 14G NDS:282mm DS:284mm W/ NIPPLE BRASS / STAINLESS DOUBLE BUTTED 14G NDS:284mm DS:282mm W/ NIPPLE BRASS Not identified
Tires

700x40C 622x40 TLR Not identified

Cockpit and contact points

4 parts

Handlebar

ALLOY FLARE 16degree, W: 420mm (S, M) / 440mm (L, XL), BB: 31,8mm, R/D: 125mm, B/R: 77mm Not identified
Headset
- Token
Saddle
- Selle Italia MODEL X
Seatpost

CARBON, DXL: 27,.2 x 300mm (S,M,L) / 27.2 x 350mm (XL) Not identified

Sizes and geometry

4 sizes Open in the geometry plotter

Enter your height to highlight matching ranges.

Size MD

Table

Reach 381mm

Stack 593mm

Wheelbase 1022mm

Head angle 71.5°

Seat angle 74.0°

Every size is drawn to the same scale, in millimeters. Explanatory schematic on an assumed 700c wheel; exact published values are in the table below.

Size Reported by the manufacturer

Complete manufacturer geometry table 4 published sizes

Complete manufacturer geometry by size
Measurement
Reachmm	369	381	397	412
Stackmm	568	593	622	650
Top tube lengthmm	526	551	581	611
Seat tube lengthmm	404	448	492	535
Head tube lengthmm	143	163	193	221
Head tube angle	70°	71.5°	71.8°	72°
Seat tube angle	74.5°	74°	73.5°	73°
Chainstay lengthmm	425	425	425	425
Wheelbasemm	1017	1022	1045	1067
Front centermm	604	609	632	654
Bottom bracket dropmm	78	78	78	78
Bottom bracket heightmm	280	280	280	280
Standover heightmm	716	755	798	833
Fork rakemm	49	48	49	49
Trailmm	75	66	63	62
Stack/reach ratio	1.54	1.56	1.57	1.58

Not published by the manufacturer: 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: Carbon
Fork material: Carbon

Suspension

Suspension configuration: Rigid

Drivetrain

Derived by Bikelake

Front chainrings: 1
Smallest chainring: 40
Largest chainring: 40
Rear sprockets: 12
Smallest sprocket: 10
Largest sprocket: 44
Lowest gear: 26.4 in
Highest gear: 116.0 in

Wheels and brakes

Wheel configuration: Same size
Brake type: Hydraulic disc

Fit and controls

Seatpost: Rigid seatpost
Shifting: Electronic

Additional specifications

Bottom bracket standard: T47
Tire width: 40c
Wheel material: Carbon
Wheel size: 700c

Technical analysis

3 measures

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

Lowest gear

26.4 gear inches

This value is within the central range for this class.

Cohort: Road / Gravel Model year: 2026
Sample: 1,455 bicycles with this information
Coverage: 73.2% of the class

Highest gear

116.0 gear inches

This value is within the central range for this class.

Cohort: Road / Gravel Model year: 2026
Sample: 1,455 bicycles with this information
Coverage: 73.2% of the class

Shifting

Electronic

706 of 1,980 bicycles with this information use electronic shifting.

Cohort: Road / Gravel Model year: 2026
Sample: 1,980 bicycles with this information
Coverage: 99.6% of the class

Gearing

Estimated speeds at 80 rpm

Lowest gear: 10.1 km/h
Highest gear: 44.4 km/h

Total gear range 440%

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: 26.4–116.0 gear inches
Class reference (p10–p90): 22.8–127.6 gear inches; The band runs from p10 for the lowest gear to p90 for the highest gear.

Cohort: Road / Gravel Model year: 2026
Lowest gear: 1455 bicycles with this information, 73.2% of the class
Highest gear: 1455 bicycles with this information, 73.2% 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 2026 builds
Specification	This bicycle Polygon Tambora G8X	Polygon Tambora A4	Polygon Tambora A5	Polygon Tambora A9X	Polygon Tambora G4	Polygon Tambora G5
Frame
Frame material	Carbon	Aluminum	Carbon	Carbon	Aluminum	Carbon
Drivetrain
Front chainrings	1	2	2	2	1	1
Smallest chainring	40	31	32	31	40	40
Largest chainring	40	48	48	48	40	40
Rear sprockets	12	11	11	12	10	11
Smallest sprocket	10	11	11	11	11	11
Largest sprocket	44	34	34	34	48	42
Lowest gear	26.4 in	26.4 in	27.3 in	26.4 in	24.2 in	27.6 in
Highest gear	116.0 in	126.6 in	126.6 in	126.6 in	105.5 in	105.5 in
Brakes
Brake type	Hydraulic disc	Hydraulic disc	Hydraulic disc	Hydraulic disc	Mechanical disc	Hydraulic disc
Cockpit
Shifting	Electronic	Mechanical	Mechanical	Electronic	Mechanical	Mechanical
Other specifications
Bottom bracket standard	T47	BSA	T47	T47	BSA	T47
Tire width	40c	32c	32c	32c	40c	40c
Wheel material	Carbon	Aluminum	Aluminum	Carbon	Aluminum	Aluminum
Tire clearance	Not informed	Maximum tire width: 45c	Maximum tire width: 45c	Not informed	Not informed	Not informed