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Transition

SentinelCarbon XO AXS

Claimed weight33.2 lbs / 15.07 kg (Size MD)Complete bike

FrameSentinel Carbon 150mmFox Float 36 GRIP X2 Factor…

GroupsetSRAM POD Ultimate Bridg…SRAM XS-1295 T-Type (10-5…

WheelsDT Swiss XM 481; DT Swi…Maxxis Assegai 3C EXO+ (2.5)

Tire clearance64 mm

The third-generation Transition Sentinel refines the brand's popular 150mm-travel trail platform, shifting its character slightly away from a pure gravity sled toward a more versatile, energetic all-mountain machine. Built around a 160mm fork and Transition’s Horst-link suspension, the V3 modernizes the chassis with mixed-wheel compatibility via a lower shock mount flip chip, allowing riders to swap the stock 29-inch rear wheel for a 27.5-inch hoop.

While the silhouette remains familiar, the frame introduces size-specific chainstay lengths to better balance weight distribution across an expanded size range. Carbon models also gain a new downtube storage hatch, keeping essentials low in the frame and separate from the water bottle mount. Transition also tweaked the suspension kinematics to provide more early-stroke support, and the frame is now officially approved for a longer-stroke shock to bump rear travel to 160mm.

Transition Sentinel

Build

Size

$6,399See deal

01 / Buy

Where to get it.

No retailers stocking size MD.

Size

0 retailers · Size MD

No retailers carrying size MD right now.

02 / Specifications

Spec sheet.

Every component shipped with this build.

01Frameset

4 components

FrameSentinel Carbon 150mm

ForkFox Float 36 GRIP X2 Factory (160mm)

Rear shockFox Float X Factory (205x60mm)

Weight33.2 lbs / 15.07 kg (Size MD)

02Drivetrain & brakes

10 components

Shift leversSRAM POD Ultimate Bridge MMX

Rear derailleurSRAM X0 AXS Eagle Transmission

CassetteSRAM XS-1295 T-Type (10-52t)

ChainSRAM X0 Eagle Transmission

CranksetSRAM X0 Eagle DUB T-Type (30t/165mm)

Bottom bracketSRAM DUB

Front brakeSRAM Maven Silver

Rear brakeSRAM Maven Silver

Front rotorSRAM HS2 200mm

Rear rotorSRAM HS2 180mm

03Wheels & tires

4 components

Front wheelDT Swiss XM 481; DT Swiss 350 Classic DEG; DT Swiss Competition

Rear wheelDT Swiss XM 481; DT Swiss 350 Classic DEG; DT Swiss Competition

Front tireMaxxis Assegai 3C EXO+ (2.5)

Rear tireMaxxis Minion DHR II 3C EXO+ (2.4)

04Cockpit & contact

5 components

StemANVL Swage (40mm)

HandlebarsOneUp Carbon Bar — XS/SM: 800x20mm; MD/LG/XL/XXL: 800x35mm

SaddleSDG Bel Air 3 LUX

SeatpostFox Transfer Factory — XS: 120mm; SM: 150mm; MD: 180mm; LG: 210mm; XL/XXL: 240mm

Grips/TapeODI Elite Flow Lock-On

03 / Geometry

Geometry & fit.

6 sizes published.

The Sentinel’s geometry balances steep-terrain capability with pedaling efficiency, though it requires some setup attention. A steep effective seat tube angle—measuring around 78.3 degrees on carbon models—places the rider in a strong, upright position that keeps the front wheel planted on steep ascents. However, this steep angle creates a relatively short effective top tube, which can make the seated pedaling position feel slightly cramped for riders with longer torsos.

Handling is heavily influenced by the bike's tall static bottom bracket. While this provides excellent pedal clearance for ratcheting through chunky, technical climbs, it creates a higher dynamic ride height that can feel less settled in sweeping corners. Transition steepened the head tube angle slightly to 64 degrees, which keeps the steering responsive at lower speeds. Meanwhile, the move to size-specific chainstays ensures that the rear center grows proportionally with the reach, helping to maintain a centered weight distribution and predictable traction whether riding the smallest or largest frame sizes.

Reach × Stack · size MDmm

Where the handlebar sits relative to the bottom bracket — the single most important fit pair.

01Fit geometry5 values

Stack621 mm

Reach455 mm

Top tube577 mm

Headtube length110 mm

Seat tube length390 mm

02Component geometry4 values

Crank length165 mm

Handlebar width800 mm

Stem length40 mm

Dropper travel180 mm

03Handling geometry6 values

Headtube angle64°

Seat tube angle78.9°

BB height350 mm

BB drop25 mm

Wheelbase1237 mm

Chainstay length442 mm

Which size should I buy?

Slide your height to see the recommended size. GearWise's fit algorithm works from the published stack, reach, and ETT — the brand's own recommendation may differ.

Your height

5'8"173 cm

5'0"5'5"5'10"6'3"6'7"

Recommended sizeMDBased on stack, reach & ETT for your height · score 80/100.

→Calculated from GearWise's own stack / reach / ETT algorithm — the brand's size chart may recommend a different size, and a proper bike fit beats any calculator.

04 / Other builds

The lineup.

9 builds, ranging $3,499 – $9,999.

The Sentinel lineup spans nine builds across aluminum and carbon frames. The primary structural difference between the materials is that alloy frames skip the downtube storage compartment, though they maintain the same suspension layout and mixed-wheel compatibility.

The build ladder starts with Shimano Deore components and RockShox base-level suspension, offering a functional entry point for budget-conscious riders. The mid-tier Alloy XT and Carbon XT builds are widely considered the value sweet spots, pairing reliable Shimano XT drivetrains and four-piston brakes with highly adjustable RockShox Select+ or Ultimate suspension. Transition notably equips these models with robust Maxxis EXO+ tires and large brake rotors right out of the box, saving aggressive riders from immediate aftermarket upgrades.

At the premium end, the Carbon XO AXS and XTR Di2 builds switch to Fox Factory suspension and electronic shifting. Across all tiers, the bikes feature long-travel dropper posts tailored to the frame size, ensuring riders can get the saddle completely out of the way on steep descents.

—Carbon XTR Di2

—

$9,999

— · Currently viewingCarbon XO AXS

—

$7,999On this page

05 / Reviews

From the press.

19 reviews from the cycling press.

Reviewers characterize the latest Sentinel as a highly active, energetic trail bike that rewards dynamic riding over passive plowing. The revised suspension kinematics provide a supportive platform that encourages riders to pop off trail features, with one tester noting the bike feels like it is "dancing with it" (Singletrackworld) rather than simply dominating the terrain. This sprightly character makes the bike surprisingly engaging on rolling singletrack and technical climbs.

However, testers consistently pointed to the stock RockShox Super Deluxe Ultimate rear shock as a limiting factor for aggressive descending. Multiple reviewers found the factory compression damping "bizarrely light" (Blisterreview), causing the rear end to blow through its mid-stroke on square-edged hits and feel unsettled at speed. Swapping to a firmer shock tune was widely reported to drastically improve the bike's composure.

Cornering performance also drew nuanced feedback. While the stiffened frame tracks precisely, the relatively high bottom bracket left some riders feeling "less grounded" (PinkBike) in fast, machine-built berms. To mitigate this, several reviewers preferred running the bike in its mixed-wheel configuration, which lowers the chassis slightly and improves high-speed cornering stability without sacrificing the bike's signature agility.