Overview
The 2025 Transition Sentinel is Trail Town’s most refined offering, delivering 160mm of front and 150mm of rear travel in a 29″ platform. Available across six sizes (XS to XXL), the Sentinel offers excellent reach and stack progression. The 64° head angle, combined with Transition’s proven suspension platform, creates a trail bike that’s equally at home on flowy berms and technical rock gardens.
Geometry Table
| Measurement | SM | MD | LG | XL | XXL |
|---|---|---|---|---|---|
| Reach (mm) | 430 | 455 | 480 | 505 | 530 |
| Stack (mm) | 615 | 621 | 633 | 642 | 651 |
| Seat Tube Length (mm) | 360 | 390 | 430 | 460 | 490 |
| Eff. Seat Angle | 79.3° | 78.7° | 78.3° | 77.9° | 77.6° |
| Head Tube Angle | 64° | 64° | 64° | 64° | 64° |
| Chainstay (Carbon, mm) | 442 | 442 | 448 | 448 | 448 |
| Wheelbase (Carbon, mm) | 1208 | 1237 | 1273 | 1302 | 1332 |
| BB Drop (mm) | 25 | 25 | 25 | 25 | 25 |
| BB Height (mm) | 350 | 350 | 350 | 350 | 350 |
Geometry Diagram
Detailed geometry specifications from manufacturer data. Contact the manufacturer for complete, size-specific measurements or visit their official website.
Key Specs
Frame: Aluminum/Carbon, 150mm rear travel. Fork: RockShox Lyrik Ultimate, 160mm. Shock: RockShox Super Deluxe Ultimate. Drivetrain: SRAM GX Eagle AXS 12-speed (base models) up to XX1 Eagle AXS (top spec). Brakes: SRAM Code Ultimate. Weight: ~15.07kg (carbon MD). The Sentinel uses Transition’s proven four-bar suspension for efficiency and composure.
Ride Characteristics
The Sentinel feels spacious and planted. The six-size range ensures proper fit across a huge spectrum of riders. Reach values from 415mm (XS) to 530mm (XXL) provide confident positioning. The 150mm rear travel paired with 160mm fork soaks up trail chop while remaining lively. On climbs, the steep seat tube angle and efficient suspension platform keep power going forward. This is Transition’s bike for riders who want capability without compromise.
Comparable Models
The Transition Sentinel 2025 competes with: Trek Fuel EX, Santa Cruz Hightower, Specialized Stumpjumper, YT Jeffsy, Ibis Ripmo.
Frequently Asked Questions
Why does the Sentinel come in six sizes?
The XS to XXL range allows Transition to accommodate riders from about 5’0″ to 6’8″, ensuring proper fit and geometry for all body types.
What is the wheelbase range on the Sentinel?
Wheelbase ranges from 1173mm (XS) to 1332mm (XXL), scaling proportionally with frame size for balanced geometry across the range.
Is the Sentinel available in aluminum?
Yes. Transition offers both aluminum and carbon options. The aluminum models are more affordable and equally capable, with slightly higher weight.
Can the Sentinel run a mullet setup?
Yes, select sizes support mullet configuration for riders who prefer the nimbleness of a 27.5″ rear paired with 29″ front wheel.
What is the BB drop on the Sentinel?
The consistent 25mm BB drop across all sizes keeps the center of gravity reasonable while maintaining cornering confidence.
Related Geometry
More Transition geometry: Transition Patrol 2026 Geometry, Transition Spire 2025 Geometry.
Compare trail bikes: 2023 Giant Stance Geometry, 2023 Giant Trance Geometry, 2023 Norco Fluid FS Geometry.