Polygon Tambora G4 vs Marin Gestalt
A side by side comparison of two gravel bikes available in Australia, on price and specs. The Polygon Tambora G4 is the lower-priced of the two.
Key differences
- Price: the Tambora G4 costs $50 less at the prices shown.
- Gearing: 1x10 Microshift Advent X on the Tambora G4, 2x8 Shimano Claris on the Gestalt.
- Stock tyres: about 40 mm wide on the Tambora G4, 36 mm on the Gestalt.
- Sizes: 4 on the Tambora G4 (S, M, L, XL), 6 on the Gestalt (50, 52, 54, 56, 58, 60).
Worked out from each bike's published specification and the price shown on its page. The full side by side table and a to-scale geometry overlay are below.
| 2 of 4 bikesDeltas are against the baseline | |||
|---|---|---|---|
| Price and where to buy | |||
| Current Australian price | $1,199.99Lowest | $1,249.99 | |
| RRP | $1,299.99 | $1,249.99 | |
| Price source | At BikesOnline, was $1,699.99. In stock, checked 3 Nov 2026. | At BikesOnline, was $1,499.99. In stock, checked 3 Nov 2026. | |
| Retailers | BikesOnline | BikesOnline | |
| Overview | |||
| Category | Gravel | Gravel | |
| Type | Non-electric | Non-electric | |
| Model year | 2024 | 2025 | |
| Frame and suspension | |||
| Frame | Aluminium | Aluminium | |
| Fork | Carbon rigid | aluminium | |
| Wheels and tyres | |||
| Wheelset | Alloy double wall, 32H | Marin alloy double wall | |
| Wheel size | 700c | 700c | |
| Stock tyres | 700x40C | 700x36c | |
| Max tyre clearance | 45 mm | 45 mmsame | |
| Drivetrain | |||
| Groupset | Microshift Advent X | Shimano Claris | |
| Shifting | Mechanical, 1x | Mechanical, 2x | |
| Crank | Alloy, 40T | FSA Tempo Compact | |
| Chainrings | Not published | 50/34 | |
| Cassette | Microshift Advent X CS-H104, 10-speed | SunRace 8-speed | |
| Cassette speeds | 10 | 8 | |
| Lowest gearRatio of smallest ring to biggest cog. Lower is easier climbing. | Not published | 1.06 | |
| Highest gearBiggest ring to smallest cog. Higher is a faster top speed. | Not published | 4.55 | |
| Gearing character | Not published | Endurance gearing | |
| Brakes and weight | |||
| Brakes | Tektro MD-C550 mechanical disc | Tektro MD-C400 mechanical disc | |
| Rotors | 160mm | 160/160 | |
| Geometry | |||
| Size shown | M | 54 | |
| Stack | 593 mm | 582 mm-11 mm | |
| Reach | 381 mm | 377 mm-4 mm | |
| Stack to reachHigher is more upright, lower is more stretched out. | 1.56 | 1.54-0.02 | |
| Head angleLower (slacker) is calmer at speed, higher (steeper) is quicker steering. | 71.5 deg | 71.5 degsame | |
| Seat angle | 74.0 deg | 73.5 deg-0.5 deg | |
| Wheelbase | 1,022 mm | 1,024 mm+2 mm | |
| Chainstay | 425 mm | 432 mm+7 mm | |
| BB drop | 78 mm | 78 mmsame | |
Geometry overlay
- Polygon Tambora G4 (size M) is the baseline.
- Marin Gestalt (size 54): 11 mm lower stack, 4 mm shorter reach, 2 mm longer wheelbase, 7 mm longer chainstays.
Stack, reach, head and seat angles, wheelbase, chainstay and BB drop are drawn to scale from published charts. Tube shapes are schematic. Sizes differ between these bikes, so check the size you would actually ride.
BikeFinder Data Profile. Geometry and component figures are researched from published manufacturer and retailer sources, not physical ride tests, and can vary by model year.
Specs and pricing are listed in AUD and sourced from Australian retail listings. Confirm current details with the seller before purchase.