2026 Polygon Siskiu T T8 vs 2025 Trek Fuel EX
The Trek Fuel EX size closest to your M is the ML. Compare the ML instead
What changes on the Trek Fuel EX
Compared with the Polygon Siskiu T T8 in M, the Trek Fuel EX in XS places the top of the head tube 35 mm lower and 65 mm further back, relative to the bottom bracket. Its wheelbase is 69 mm shorter, which can contribute to quicker direction changes.
- Frame stack
- −35 mm
- Lower front end
- Frame reach
- −65 mm
- Shorter frame reach
- Wheelbase
- −69 mm
- Shorter: quicker to change direction
- Head angle
- ±0.0°
- About the same head angle
- Chainstays
- +5 mm
- Longer: more planted
The two frames
Only the Polygon Siskiu T T8 is drawn. The Trek Fuel EX numbers we have for size XS are missing the seat angle.
Geometry side by side
| Measurement | Polygon Siskiu T T8 M | Trek Fuel EX XS | Difference |
|---|---|---|---|
| Reach | 465 | 400.2 | −65 mm |
| Stack | 609 | 574.1 | −35 mm |
| Head tube angle | 64.5 | 64.5 | ±0.0° |
| Seat tube angle | 71.2 | not listed | |
| Effective top tube | 595 | 516.2 | −79 mm |
| Chainstay length | 430 | 435 | +5 mm |
| Wheelbase | 1214 | 1144.8 | −69 mm |
| BB height | 337.5 | 332 | −6 mm |
| Standover | 705 | 716.8 | +12 mm |
| Seat tube length | 400 | 360 | −40 mm |
| Head tube length | 95 | 95 | ±0 mm |
| BB drop | not listed | 25 |
Differences are the Trek Fuel EX minus the Polygon Siskiu T T8. Full charts: 2026 Polygon Siskiu T T8, 2025 Trek Fuel EX.
Where each sits in its class
Polygon Siskiu T T8Trek Fuel EX
Each bike is ranked against the other trail bikes on Quiver, on frame geometry alone. Not your hand position or ride feel.
What each ships with
The stock build of each bike's first listed trim. Parts that match are dimmed.
| Part | Polygon Siskiu T T8T8 | Trek Fuel EX5 |
|---|---|---|
| Frame | Polygon Siskiu T | Trek Fuel EX |
| Fork | Fox 34 Float Rhythm | RockShox Recon Silver |
| Rear shock | Fox Float P-S | X-Fusion Pro 2 |
| Shifter | Shimano SL-M7100-R SLX | Shimano Deore M6100 |
| Derailleur | Shimano SLX | Shimano Deore M6100 |
| Cassette | Shimano SLX | Shimano Deore M6100 |
| Chain | KMC X-12 | Shimano Deore M6100 |
| Crankset | Shimano SLX | Shimano MT512 |
| Chainring | Shimano SLX | not listed |
| Wheelset | Polygon MT6 | Bontrager Line TLR 30 |
| Tire | Maxxis Dissector | Bontrager Gunnison Elite XR |
| Brake | Shimano Deore M4100 | Shimano MT200 |
| Rotor | Shimano Rotor | Shimano SM-RT56 |
| Handlebar | Polygon EXPERT | TranzX JD-YSI-22PLQ |
| Headset | FSA headset | not listed |
| Dropper post | Polygon Expert | TranzX JD-YSI-22PLQ |
| Bottom bracket | not listed | Shimano MT501 |
| Stem | not listed | Bontrager Comp |
| Grips | not listed | Bontrager XR Trail |
| Saddle | not listed | Bontrager Arvada |
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