Tambora A4
OverviewAbout the Polygon Tambora A4
The Polygon Tambora A4 is a gravel bike, built on an aluminium frame, listed at $1,699.99 at BikesOnline. A drop-bar all-road bike for gravel, dirt and mixed surfaces.
How it comparesThe Tambora A4 against similarly priced bikes
- At $1,699.99 it costs less than 82% of the 80 gravel bikes we list.
- Head angle: 71.8 degrees, steeper, so quicker steering than the middle of similarly priced gravel bikes (71.0 degrees).
- Reach (size M): 383 mm, about the same as similarly priced gravel bikes (middle 389 mm).
- Lowest gear ratio: 0.91, about the same as similarly priced gravel bikes (middle 0.88).
- Gears at the back: 11-speed, more than the middle of similarly priced gravel bikes (10-speed).
- Stock tyre width: 32 mm, narrower than the middle of similarly priced gravel bikes (40 mm).
Closest alternatives on price
$27 more · 9-speed vs 11-speed · mechanical brakes · 38 mm tyres vs 32 mm
$100 less · 9-speed vs 11-speed · 40 mm tyres vs 32 mm
$100 more · 12-speed vs 11-speed · 45 mm tyres vs 32 mm
$199 more · 9-speed vs 11-speed · mechanical brakes · 38 mm tyres vs 32 mm
Compare the Tambora A4 with the two closest side by side
Compared with the 19 similar gravel bikes on BikeFinder priced $1,200 to $2,300, using each bike's published specs and the price shown on its page.
SizingWhat size Tambora A4 do I need?
Enter your height to see the size Polygon recommends.
| Size | Rider height | In feet |
|---|---|---|
| S | 150 to 163 cm | 4 ft 11 in to 5 ft 4 in |
| M | 163 to 175 cm | 5 ft 4 in to 5 ft 9 in |
| L | 175 to 188 cm | 5 ft 9 in to 6 ft 2 in |
| XL | 188 to 196 cm | 6 ft 2 in to 6 ft 5 in |
Rider heights from Polygon's size chart. Height is a starting point: arm and leg length, flexibility and riding style all matter, so a test ride beats any chart. How bike sizing works.
SpecificationsWhat we know
- Brand
- Polygon
- Model year
- 2026
- Category
- Gravel
- Frame
- Aluminium
- Wheel size
- 700c
- Drivetrain
- Shimano GRX 2x11
- Brakes
- Disc
- Frame sizes
- S, M, L, XL
- Price
- $1,699.99 at BikesOnline, was $2,399.99. In stock, checked 3 Nov 2026.
Specs and pricing are listed in AUD and sourced from Australian retail listings. Confirm the current details and availability with the seller before purchase.
GeometrySize M
- Stack
- 591 mm
- Reach
- 383 mm
- Stack/reach
- 1.54
- Head angle
- 71.8 deg
- Seat angle
- 74.3 deg
- Wheelbase
- 1003 mm
- Chainstay
- 415 mm
- BB drop
- 79 mm
- Standover
- 741 mm
GearingRatios
Ratios are derived from the chainrings and cassette. They describe the gearing, not any rider's ability.
Drivetrain & buildFull specification
- Groupset
- Shimano GRX
- Shifting
- Mechanical
- Drive
- 2x
- Speeds
- 11
- Crank
- Prowheel RPZ C701X TT
- Chainrings
- 48/31
- Cassette
- Shimano CS-HG700, 11-34T, 11-Speed
- Rear derailleur
- Shimano GRX RD-RX810, 11-Speed
- Brakes
- Shimano GRX Hydraulic Disc, Flat-Mount
- Rotors
- 160mm
- Wheelset
- Polygon Alloy Double-Wall, 20 mm Inner Width, 622 x 32H, Tubeless-Ready
- Rim internal width
- 20 mm
- Stock tyre
- 700x32c
- Fork material
- Carbon
- Seatpost
- Polygon Expert, 27.2 x 400 mm
- Cockpit
- Polygon Expert, 90 mm (S, M) / 100 mm (L, XL), 31.8 mm Clamp, 7 deg Rise / Polygon Expert, 420 mm (S, M) / 440 mm (L, XL), 31.8 mm Clamp, 125 mm Drop, 77 mm Reach
- Saddle
- LINC Flux 2
Bike DNAWhat the numbers say
- Position
- Stack-to-reach 1.54 gives an upright, comfort-oriented riding position.
- Steering
- A 71.8 deg head angle points to balanced steering.
- Climbing
- Lowest ratio 0.91 is a low climbing gear that still handles steep pitches.
Derived from the published geometry and gearing above. It describes the numbers, not a ride test.
BikeFinder Data Profile: geometry and specification researched from published sources (BikesOnline product page (specification list and geometry table)), verified 2026-11-03. This is a specification analysis, not a physical ride review.
Where to buyStockist
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