Good to know: Integrated cockpit
Integrated cockpit (a one-piece bar and stem) on at least one build. Changing the length means replacing the whole cockpit, and not every length exists. Check which length the bike actually ships with before you buy.
Geometry ?
Polygon Tambora A 2026 geometry in sizes S–XL: stack 566–648 mm, reach 371–415 mm, head angle 70.2–72.3°.
| S | M | L | XL | |
|---|---|---|---|---|
| Stack | 566 mm | 591 mm | 621 mm | 648 mm |
| Reach | 371 mm | 383 mm | 400 mm | 415 mm |
| Head angle | 70.2° | 71.8° | 72.1° | 72.3° |
| Seat angle | 74.8° | 74.3° | 73.8° | 73.3° |
| Seat tube (?) | 404 mm | 448 mm | 492 mm | 535 mm |
| Head tube | 143 mm | 163 mm | 193 mm | 221 mm |
| Top tube (effective) | 526 mm | 550 mm | 581 mm | 610 mm |
| BB drop | 79 mm | 79 mm | 79 mm | 79 mm |
| Chainstay | 415 mm | 415 mm | 415 mm | 415 mm |
| Wheelbase | 997 mm | 1003 mm | 1026 mm | 1048 mm |
| Standover | 701 mm | 741 mm | 784 mm | 819 mm |
| Stock build by size | ||||
| Stem Tambora A9X | 100 mm | 100 mm | 110 mm | 110 mm |
| Stem Tambora A5 | 90 mm | 90 mm | 100 mm | 100 mm |
| Stem angle Tambora A9X | 0° | 0° | 0° | 0° |
| Stem angle Tambora A5 | −7° | −7° | −7° | −7° |
| Bar width Tambora A9X | 400 mm | 400 mm | 420 mm | 420 mm |
| Bar width Tambora A5 | 420 mm | 420 mm | 440 mm | 440 mm |
(?) by the seat tube length: the manufacturer doesn’t say whether it’s measured centre to centre (c-c) or centre to top (c-t).
Source: polygonbikes.com, checked 1 Nov 2026 · bar position: worked out from published data
Stock build
Tambora A9X ≈ €3,679
- Groupset
- Shimano GRX Di2 RX825 2×12
- Shifters
- Shimano GRX Di2 ST-RX825
- Cranks
- Shimano GRX FC-RX820 48×31T
- Stem
- BLKTEC R8 Integrated
- Handlebar
- BLKTEC R8 Integrated
- Seatpost
- Carbon, 27.2×400 mm
- Saddle
- Fizik Terra Argo X7
- List price
- US$3,999 (polygonbikes.com, 1 Nov 2026)
Tambora A5 ≈ €2,300
- Groupset
- Shimano GRX RX600 2×11 (RD-RX810)
- Shifters
- Shimano GRX ST-RX600
- Cranks
- Praxis Alba GR M30 48-32T
- Stem
- Polygon Expert, 31.8, 7°
- Handlebar
- Polygon Expert, 31.8
- Seatpost
- Carbon, 27.2×400 mm
- Saddle
- Fizik Terra Argo X7
- List price
- US$2,500 (polygonbikes.com, 1 Nov 2026)
Source for all builds: polygonbikes.com, checked 1 Nov 2026
Frames with similar geometry
Stack and reach within 12 mm of size S (stack 566 / reach 371 mm).
Stack and reach within 12 mm of size M (stack 591 / reach 383 mm).
Stack and reach within 12 mm of size L (stack 621 / reach 400 mm).
Stack and reach within 12 mm of size XL (stack 648 / reach 415 mm).
Spotted a mistake or a missing build? Let me know.