2026 Transition Sentinel Alloy vs 2026 Forbidden Reya Tier
The S2 is the Forbidden Reya Tier size closest to your M Transition Sentinel 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 Forbidden Reya Tier
Compared with the Transition Sentinel Alloy in M, the Forbidden Reya Tier in S2 places the top of the head tube 9 mm lower and about as far forward, relative to the bottom bracket. Its wheelbase is 33 mm shorter, which can contribute to quicker direction changes.
- Frame stack
- −9 mm
- Lower front end
- Frame reach
- ±0 mm
- About the same reach
- Wheelbase
- −33 mm
- Shorter: quicker to change direction
- Head angle
- +1.0°
- Steeper: sharper steering
- Chainstays
- n/a
- One of the bikes has no number for this
The two frames
Only the Transition Sentinel Alloy is drawn. The Forbidden Reya Tier numbers we have for size S2 are missing the chainstay length.
Geometry side by side
| Measurement | Transition Sentinel Alloy M | Forbidden Reya Tier S2 | Difference |
|---|---|---|---|
| Reach | 455 | 455 | ±0 mm |
| Stack | 621 | 612 | −9 mm |
| Head tube angle | 64.0 | 65.0 | +1.0° |
| Seat tube angle | 73.0 | 71.3 | −1.7° |
| Effective top tube | 577 | 596 | +19 mm |
| Chainstay length | 442 | not listed | |
| Wheelbase | 1237 | 1204 | −33 mm |
| BB drop | 25 | not listed | |
| Standover | 690 | 717 | +27 mm |
| Seat tube length | 390 | 420 | +30 mm |
| Head tube length | 110 | 105 | −5 mm |
| BB height | not listed | 331 | |
| Fork length | not listed | 541 |
Differences are the Forbidden Reya Tier minus the Transition Sentinel Alloy. Full charts: 2026 Transition Sentinel Alloy, 2026 Forbidden Reya Tier.
Where each sits in its class
Transition Sentinel AlloyForbidden Reya Tier
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 Sentinel AlloyAlloy Eagle 70 | Forbidden Reya TierTier 1 |
|---|---|---|
| Frame | Transition Sentinel | Forbidden Reya |
| Fork | RockShox Psylo | Fox 34 Factory SL |
| Rear shock | RockShox Super Deluxe Base | Fox Float Factory |
| Shifter | SRAM Eagle 70 Transmission | SRAM Pod Rocker Controller |
| Derailleur | SRAM Eagle 70 Transmission | SRAM XX XX SL |
| Cassette | SRAM Eagle 70 Transmission | SRAM XX SL Eagle Transmission |
| Chain | SRAM Eagle 70 Transmission | SRAM XX SL |
| Crankset | SRAM Eagle 70 Transmission | SRAM XX SL |
| Chainring | SRAM Eagle 70 Transmission | SRAM 32T |
| Wheelset | WTB ST | not listed |
| Tire | Maxxis Assegai, Maxxis Minion DHR II DD | Maxxis Rekon Race |
| Brake | SRAM Maven Base | SRAM Motive Ultimate |
| Rotor | SRAM CenterLine | SRAM HS2 |
| Handlebar | Race Face Chester | OneUp Components Carbon |
| Stem | Race Face Aeffect | BikeYoke Barkeeper Stem |
| Grips | ODI Elite Flow | not listed |
| Headset | FSA No 57E | Cane Creek 40 |
| Dropper post | SDG Tellis Dropper | OneUp Components V3 Dropper Post |
| Saddle | SDG Bel Air 3 | fizik Terra Ridon X1 |
| Bottom bracket | not listed | SRAM DUB |
| Battery | not listed | SRAM AXS EP Powerpack |
| Hub | not listed | DT Swiss 240 SPLINE, DT Swiss 240 SPLINE Ratchet EXP |
| Rim | not listed | DT Swiss 1500 |
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