Tambora Series | Polygon Bikes

TAMBORA: Our Most Versatile Gravel Machine

Gravel | ACX & ALX Frames | 12 Available Builds

Whether you're a long-distance enthusiast or an adventurous explorer, the TAMBORA is here for all your gravel needs. Flip chips at the rear dropouts and fork base let you switch between gravel and all-road geometry in minutes, making the TAMBORA genuinely two-bikes-in-one. With 14 universal mounting points across the frame, it's ready to carry everything your adventure demands.

ACX Carbon Frame

Specifically tuned to balance lightweight performance with vibration damping, the ACX carbon frame is engineered to absorb chatter, allowing you to ride further with less fatigue.

Flip Chip Geometry

Flip chips located at the rear dropouts and the base of the fork allowing you to extend the wheelbase, easily switching between snappy handling or more stable configurations.

45c tire clearance

Increased tire clearance increases comfort and capability on mixed terrain.

Frame and accessory mounts

With up to 14 universal mounts , there's plenty of scope to attach any bag or kit that suits your adventure.

Choose your series

TAMBORA A9X Compare

Color /

Price

$3,999.00

EXPLORE TAMBORA A9X

TAMBORA G8X Compare

Color /

Price

$2,999.00

EXPLORE TAMBORA G8X

TAMBORA A5 Compare

Color /

Price

$2,499.00

EXPLORE TAMBORA A5

TAMBORA G7 Compare

Color /

Price

$2,499.00

EXPLORE TAMBORA G7

TAMBORA A4 Compare

Color /

Price

$1,799.00

EXPLORE TAMBORA A4

TAMBORA G5 Compare

Color /

Price

$1,799.00

EXPLORE TAMBORA G5

TAMBORA G4 Compare

Color /

Price

$899.00

EXPLORE TAMBORA G4

Build Specs

Kit	TAMBORA A9X	TAMBORA G8X	TAMBORA A5	TAMBORA G7	TAMBORA A4	TAMBORA G5	TAMBORA G4
Frame	ACX GRAVEL	ACX GRAVEL	ACX GRAVEL	ACX GRAVEL	ALX XC TRAIL FRAME	ACX GRAVEL	ALX GRAVEL
Fork	CARBON RIGID	CARBON RIGID	CARBON RIGID	CARBON RIGID	CARBON RIGID	CARBON RIGID	CARBON RIGID
Shifter	SHIMANO GRX Di2 ST-RX825, 2x12-SPEED BRIFTER	SRAM RIVAL ETAP AXS 12-SPEED BRIFTER	SHIMANO GRX ST-RX600, 2x11-SPEED BRIFTER	SRAM APEX 12-SPEED BRIFTER	SHIMANO GRX ST-RX600, 2x11-SPEED BRIFTER	SRAM APEX 1 11-SPEED BRIFTER	MICROSHIFT ADVENT X SB-M100, 1x10-SPEED BRIFTER
Crank Set	SHIMANO GRX FC-RX820, 48x31T	SRAM RIVAL 1 WIDE 40T	PRAXIS ALBA GR M30, 48-32T	SRAM APEX 1 WIDE 40T	PROWHEEL RPZ C701X TT, 48-31T	PRAXIS ALBA GR M30 40T	ALLOY 40T
Cassette	SHIMANO ULTEGRA CS-R8101, 11-34T	SRAM XG-1251 12 SPEED 10-44T XDR	SHIMANO CS-HG700, 11-34T	SRAM XPLR PG-1231 12 SPEED 11-44T	SHIMANO CS-HG700, 11-34T	SRAM PG-1130 11-SPEED 11-42T	MICROSHIFT ADVENT X CS-H104 10 SPEED 11-48T
Rear Derailleur	SHIMANO GRX Di2 RD-RX825	SRAM RIVAL XPLR ETAP AXS 12-SPEED	SHIMANO GRX RD-RX810	SRAM APEX XPLR 12-SPEED	SHIMANO GRX RD-RX810	SRAM APEX 1 11-SPEED	MICROSHIFT ADVENT X M6205GM 10-SPEED
Wheel Set	NOVATEC G24 DISC (28mm) W/ TUBELESS TAPE INSTALLED	NOVATEC G24 DISC (28mm) W/ TUBELESS TAPE INSTALLED	ALLOY DOUBLE WALL 32H	NOVATEC G24 DISC (28mm) W/ TUBELESS TAPE INSTALLED	ALLOY DOUBLE WALL 32H	ALLOY DOUBLE WALL 32H	ALLOY DOUBLE WALL 32H
Tire	MAXXIS RE-FUSE 700X32C	700x40C 622x40 TLR	MAXXIS RE-FUSE 700X32C	700x40C 622x40 TLR	MAXXIS PURSUER 700X32C	VEE RAIL 700x40C 622x40 TLR	VEE RAIL 700x40C 622x40 TLR
Brake Lever	SHIMANO RX825	SRAM RIVAL	SHIMANO ST-RX600	SRAM APEX	SHIMANO ST-RX600	SRAM APEX 1	MICROSHIFT ADVENT X SB-M100
Brake Caliper	SHIMANO GRX RX825 HYDRAULIC DISC	SRAM RIVAL HYDRAULIC DISC	SHIMANO GRX HYDRAULIC DISC	SRAM APEX HYDRAULIC DISC	SHIMANO GRX HYDRAULIC DISC	TRP HD-C711 HY-ROAD	TEKTRO MD-C550 MECHANICAL
Rotor	SHIMANO CL800, 160mm	SRAM PACELINE 160mm CL	SHIMANO RT-CL700, 160mm	SRAM PACELINE 160mm CL	SHIMANO RT-CL700, 160mm	TEKTRO TR-160mm CL	TEKTRO 160mm 6B

Compare other models

FAQ

Where are the mounts to hold gear? If I wanted to buy a bolted bag, what are the specifications? For full frame and half frame

There are 14 mounts on the Polygon Tambora series; 3 on the top tube, 7 on the down tube, 2 on the seat tube, and a pair of rear carrier mounts. We're using universal-size mounts, so there are no special specifications for the compatible bolted bag. You can freely choose the bolted bag that fits you best.
What is the biggest chainring I can fit?

The maximum chainring of Tambora series is 42T
What are the biggest rotors I can fit?

The biggest rotors for the Tambora series are 160 mm
Can you fit mudguards, pannier racks front and back?

Of course! Tambora Series can be equipped with a rear pannier or rear mudguard.
How do you change the flip chip?

The Tambora has flip chips located at the rear dropouts and the base of the fork, allowing you to easily switch between gravel and all-road configurations. Watch the full video here.
Can I fit a dropper post?

Yes! But it should be a gravel bike dropper post which commonly designed from 50mm to 125mm of travel.
Is it possible to upgrade a road bike to a gravel bike?

This should not be possible because of the small tire clearance and its fixed aggressive geometry.
What is the best configuration for bikepacking gear?

The best configuration of bikepacking typically is a lightweight and compact gear that can bring all of your needs. But it can vary depending on the individual's preferences, the specific trip's requirements, and the terrain being covered.
How does the geometry of Tambora bikes differ from gravel bikes and other road bikes?

The gravel bike has a higher stack, slacker head angle, and longer wheelbase for stability.
What are the gearing differences on gravel vs road bikes?

A gravel bike is using a bigger sprocket than a road bike.