Transition's all-rounder, the 29in wheeled Sentinel, gets enduro-focused updates that the British Columbian brand hopes will increase the scope of its versatile trail-slaying bike.
The updates are focused around a full carbon-fibre frameset, including front and rear triangles and rocker plate, which uses a specially-formulated carbon mix from Toray – a Japenese materials specialist. Transition claims this creates the perfect balance of strength, rock-strike or impact resilience, and overall stiffness.
Transition also states it's refined its EPS moulding process to create more-defined frame lines.
The updates also include a suspension kinematic that's compatible with both coil and air shocks. Transition states that it's got a 24 per cent overall progression rate that increases linearly throughout the travel.
In standard form, the 62.5mm stroke shock produces 150mm of rear wheel travel, but it's designed the bike so it can be run with 140mm of travel if a 57.5mm stroke shock is fitted.
As a brand that isn't afraid to embrace the latest trends, such as the market's appetite for longer dropper posts, Transition has given every size of the new Sentinel shorter seat-tube lengths so that increasing dropper post travel is possible.
To help accommodate long-travel droppers, it's also increased the seatpost insertion depth. This makes it possible for the small-sized bike to come standard with a 150mm dropper, while the medium has a 180mm post and the large, extra-large and extra-extra-large bikes have 210mm posts.
The new 2020 Sentinel features Transition's lifetime warranty, although this is only available to the first owner of the bike, 148mm Boost rear axle spacing, a threaded bottom bracket and – in a bold but fantastic move – external rear brake hose routing. This means swapping brakes, changing damaged hoses or bleeding them is considerably easier.
It's got a water bottle mount on the inside of the front triangle and an additional mount on the underside of the top tube, although a standard size and shaped bottle won't fit on the second set of mounts because it will foul the shock's piggyback.
2020 Transition Sentinel geometry
The new Sentinel's geometry is truly at the sharp end of modern for a trail bike.
That means we're delighted to see steep seat-tube angles across the bike's sizes, long reach figures and a meaty wheelbase.
Add to the mix a 63.6-degree head tube angle and low bottom bracket and there's no denying this bike's got an appetite for gnarly riding.
| Size | Small | Medium | Large | Extra-large | Extra-extra-large |
|---|---|---|---|---|---|
| Reach (mm) | 420 | 450 | 476 | 501 | 521 |
| Stack (mm) | 613 | 622 | 631 | 640 | 649 |
| Effective top tube length (mm) | 552 | 585 | 613 | 641 | 665 |
| Seat tube length (mm) | 350 | 390 | 430 | 460 | 490 |
| Effect seat tube angle (degrees) | 78.2 | 77.5 | 76.9 | 76.4 | 75.9 |
| Actual seat tube angle (degrees) | 70.8 | 70.8 | 70.8 | 70.8 | 70.8 |
| Head tube length (mm) | 100 | 110 | 120 | 130 | 140 |
| Head tube angle (degrees) | 63.6 | 63.6 | 63.6 | 63.6 | 63.6 |
| Chainstay length (mm) | 440 | 440 | 440 | 440 | 440 |
| Wheelbase (mm) | 1,199 | 1,233 | 1,263 | 1,292 | 1,316 |
| Bottom bracket drop (mm) | 29 | 29 | 29 | 28 | 28 |
| Standover (mm) | 671 | 688 | 700 | 712 | 722 |
| Seatpost insertion depth (mm) | 220 | 250 | 290 | 320 | 350 |
2020 Transition Sentinel models and price
The new Sentinel comes in three builds: the cheapest NX Eagle retails for £4,299.95; a mid-range GX Eagle model retails for £5,299.95; and the most expensive X01 Eagle costs £6,299.95. The frameset costs £2,999.95.
2020 Transition NX Eagle Sentinel Carbon Complete
- Frame: Toray 24T and 30T Uni-Directional Japanese carbon fibre front and rear triangles and rocker, 150mm travel
- Fork: RockShox Lyrik Select Charger RC 160mm travel
- Shock: RockShox Super Deluxe Select RT
- Groupset: SRAM NX Eagle (1×12)
- Crankset: SRAM NX Eagle (1×12)
- Brakes: SRAM Code R
- Wheels: Stans Flow D rims on Novatech D791SB/D462SB hubs
- Tyres: Maxxis Assegei 3C EXO 29 x 2.5in (f), Maxxis Minion DHRII 3C EXO 29 x 2.4in (r)
- Bar and stem: RaceFace Chester handlebar and RaceFace Aeffect R (40mm) stem
- Saddle: ANVL Forge CroMo
- Seatpost: OneUp dropper post
- Sizes: S, M, L, XL, XXL
- Price: £4,299.95
2020 Transition GX Eagle Sentinel Carbon Complete
- Frame: Toray 24T and 30T Uni-Directional Japanese carbon fibre front and rear triangles and rocker, 150mm travel
- Fork: RockShox Lyrik Ultimate RC2 160mm travel
- Shock: RockShox Super Deluxe Ultimate
- Groupset: SRAM GX Eagle (1×12)
- Crankset: SRAM GX Eagle (1×12)
- Brakes: SRAM Code RSC
- Wheels: Stans Flow S1 Team
- Tyres: Maxxis Assegei 3C EXO 29 x 2.5in (f), Maxxis Minion DHRII 3C EXO 29 x 2.4in (r)
- Bar and stem: ANVL Mandrel handlebar and ANVL Swage (40mm) stem
- Saddle: ANVL Forge CroMo
- Seatpost: OneUp dropper post
- Sizes: S, M, L, XL, XXL
- Price: £5,299.95
2020 Transition X01 Eagle Sentinel Carbon Complete
- Frame: Toray 24T and 30T Uni-Directional Japanese carbon fibre front and rear triangles and rocker, 150mm travel
- Fork: Fox Float 36 Grip 2 Performance Elite 160mm travel
- Shock: Fox Float X2 Performance Elite
- Groupset: SRAM X01 Eagle (1×12)
- Crankset: SRAM X1 carbon Eagle (1×12)
- Brakes: SRAM Code RSC
- Wheels: DT Swiss M1700 Spline 30
- Tyres: Maxxis Assegei 3C EXO 29 x 2.5in (f), Maxxis Minion DHRII 3C EXO 29 x 2.4in (r)
- Bar and stem: OneUp Carbon handlebar, ANVL Swage (40mm) stem
- Saddle: ANVL Forge Ti
- Seatpost: OneUp dropper post
- Sizes: S, M, L, XL, XXL
- Price: £6,299.95
2020 Transition Sentinel Carbon frame
- Frame: Toray 24T and 30T Uni-Directional Japanese carbon fibre front and rear triangles and rocker, 150mm travel
- Shock: Fox Float X2 Performance Elite
- Sizes: S, M, L, XL, XXL
- Price: £2,999.95
