For the past few years, the Sentinel has stood in Transitions’ lineup as the do-it-all option for riders wanting a longer travel bike that strikes a balance of travel and geometry to handle anything in their way while maintaining a pedal-friendly nature. The all-new Sentinel V3 retains its predecessor’s “send-it-all” attitude while ushering in a range of updates and incremental improvements. Updated geometry, frame kinematics, numerous detailed refinements such as frame storage, and increased frame protection pose the Sentinel V3 as the Bellingham-based manufacturers’ most comprehensive bike yet. 

Frame Features / Updates

Upon first glance, the most notable visual change to the latest version of the Sentinel is the internal frame storage found on the carbon model. Transition’s “B.O.O.M. Box” (Burritos Or Other Munchies) is their first attempt at internal frame storage and is well-executed. The door sits flush and actuates smoothly to reveal two gear bags. Unlike the name suggests, riders shouldn’t expect to fit a burrito’s worth of gear in the compartment, as the usable space is only two inches tall by three inches wide. 

The frame has a fairly similar profile to the V2 model but features a larger downtube and more aggressive lines throughout while still staying in line with the angular silhouette the Transition lineup has followed since 2020. Riders will find small but impactful refinements in the finer details of the V3’s construction with improved chainstay protection, a molded mudguard protecting the main pivot area, and redesigned cable ports. 

The V3 Sentinel can be run as a full 29” or mullet via an adjustable flip-chip except for a size XS that comes stock dual 27.5”.

Geometry / Sizing

While the days of every newly released bike getting the “longer, lower, slacker” treatment have settled down, Transition has fine-tuned the geometry of the V3 Sentinel to make it a well-rounded all-mountain option. Some areas have grown slightly, with the reach lengthening by 5mm, while the wheelbase has grown by 10mm. In its 29” configuration, the BB height is raised by 4mm. The Transition has steepened the head tube angle by .4 degrees, moving it from 63.6 to even 64 degrees. 

The most notable geometry update for the Sentinel is that it now comes with size-specific chainstays. Small and medium models boast a 442mm rear end, while large to extra-large models have a 446mm rear end. Additionally, there is an extra small model that comes with 27.5-inch wheels front and rear, featuring a shorter 436 mm chainstay. This shift to size-specific rear ends provides the ideal ride quality and handling characteristics across all sizes, so riders on either end of the sizing chart don’t have to settle for compromising ride characteristics. 

The V3 Sentinel is available in sizes XS- XXL and accommodates riders from 4’8” to 6’8” tall. 

The chart below compares the geometry between a size large full 29” V3 Sentinel to that of a V3 size large in the mixed-wheel configuration and a size large V2 Sentinel.

Suspension

 Transition has fine-tuned the suspension kinematics of the new Sentinel by combining a 25% progressive leverage curve with a consistent linear rate, enhancing anti-squat for improved pedaling and acceleration. This design allows for excellent small bump compliance and strong mid-stroke support, transitioning smoothly into a supportive end-of-stroke ramp. The Sentinel offers 150 mm of rear travel with a 205 mm x 60 mm shock, and can be upgraded to 160 mm with a 205 mm x 65 mm shock, featuring a sag range of 26-33% for customizable ride feel—whether you prefer a playful or planted setup. 

Sentinel V3 for Sale // Custom Build a Sentinel V3

Transition Sentinel frames are now available on our custom builder! Build yours up custom today or stop by our showroom in Bellingham, Wa. to check out select complete builds. 

Verdict

The Transition Sentinel V3 solidifies its position as a versatile all-mountain bike, combining thoughtful updates with the proven “send-it-all” spirit of its predecessor. With refined geometry, improved suspension kinematics, and innovative internal frame storage, this bike caters to a wide range of riders and preferences. The introduction of size-specific chainstays ensures optimal handling, allowing for a tailored ride experience without compromise. Overall, the Sentinel V3 stands out as Transition's most comprehensive offering yet, ready to tackle any trail with confidence and style.