2025 Transition Scout Alloy vs 2027 Polygon Siskiu T T27 EVO
The XS is the Polygon Siskiu T T27 EVO size closest to your M Transition Scout Alloy. We match frame stack and reach. This is a geometry comparison, not a fit recommendation; stem, spacers, handlebars and saddle setup also affect your riding position.
What changes on the Polygon Siskiu T T27 EVO
Compared with the Transition Scout Alloy in M, the Polygon Siskiu T T27 EVO in XS places the top of the head tube 24 mm lower and 40 mm further back, relative to the bottom bracket. Its wheelbase is 71 mm shorter, which can contribute to quicker direction changes.
- Frame stack
- −24 mm
- Lower front end
- Frame reach
- −40 mm
- Shorter frame reach
- Wheelbase
- −71 mm
- Shorter: quicker to change direction
- Head angle
- +1.0°
- Steeper: sharper steering
- Chainstays
- −5 mm
- Shorter: livelier
The two frames
Transition Scout Alloy, MPolygon Siskiu T T27 EVO, XSDrawn to scale and lined up at the bottom bracket.
Geometry side by side
| Measurement | Transition Scout Alloy M | Polygon Siskiu T T27 EVO XS | Difference |
|---|---|---|---|
| Reach | 460 | 420 | −40 mm |
| Stack | 604 | 579.87 | −24 mm |
| Head tube angle | 64.0 | 65 | +1.0° |
| Seat tube angle | 72 | 71 | −1.0° |
| Effective top tube | 593 | 559.2 | −34 mm |
| Chainstay length | 430 | 425 | −5 mm |
| Wheelbase | 1217 | 1146.4 | −71 mm |
| BB drop | 18 | not listed | |
| BB height | 337 | 335 | −2 mm |
| Standover | 673 | 666 | −7 mm |
| Seat tube length | 390 | 375 | −15 mm |
| Head tube length | 125 | 90 | −35 mm |
Differences are the Polygon Siskiu T T27 EVO minus the Transition Scout Alloy. Full charts: 2025 Transition Scout Alloy, 2027 Polygon Siskiu T T27 EVO.
Where each sits in its class
Transition Scout AlloyPolygon Siskiu T T27 EVO
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 | Transition Scout AlloyAlloy Deore | Polygon Siskiu T T27 EVOT27 EVO |
|---|---|---|
| Frame | Transition Scout | Polygon ALX Trail |
| Fork | RockShox Psylo Gold | RockShox Recon Silver TK |
| Rear shock | RockShox Deluxe Select+ | RockShox Deluxe Select+ |
| Shifter | Shimano Deore | Shimano Deore M6100 |
| Derailleur | Shimano Deore | Shimano Deore M6100 |
| Cassette | Shimano Deore M6100 | Shimano Deore M6100 |
| Chain | Shimano Deore XT | KMC X-12 |
| Crankset | Shimano Deore M6100 | Shimano Deore M6120 |
| Wheelset | Novatec D791SB/D902SB with WTB ST i30 | Polygon MT6 |
| Tire | Maxxis Minion DHR II DD | Maxxis Dissector |
| Brake | Shimano Deore XT | Shimano Deore M4100 |
| Rotor | Shimano Deore M6120 | Shimano SM-RT54 |
| Handlebar | Race Face Chester | Polygon EXPERT |
| Stem | Race Face Aeffect R | Polygon EXPERT |
| Grips | ODI Elite Flow | not listed |
| Headset | FSA 57E | FSA No 57E |
| Dropper post | SDG Tellis Dropper | X-Fusion Manic |
| Saddle | SDG Bel Air 3 | fizik Terra Alpaca X5 |
| Chainring | not listed | Shimano 32 |
| Bottom bracket | not listed | Shimano |
| Pedals | not listed | Alloy |
| Seatpost | not listed | Dropper Post |
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