The Updated Transition Sentinel Doesn’t Follow the Current Mini-DH Bike Trend

It seems that the engineers at Transition were pretty stoked with this all-mountain bike to begin with, and made a few final touches on their otherwise dialed design with this update.
Gear mount bolts under the top tube is a trend we can all appreciate. Photos: Transition Bikes

Transition has made some sweet updates to their 29″ all-mountain/enduro bike, but unlike some new 29ers, the Sentinel isn’t stretched to near-DH-sled travel numbers. There is an unavoidable tipping point for progressive geometry and travel numbers, where the benefits don’t outweigh the compromises. Have we reached it?

While a lot of 29er frames are being updated to fit around 170-180mm of fork travel, and 160-170 rear axle path, the Sentinel only gained 10mm of rear travel and maintained the same fork squish as the previous version. With 150mm out back and 160 under the bars, it seems Transition has found the balance point with this bike.

Geometry measurements for the new frames also hang close to the prior Sentinel, with the reach only lengthening on the size large and XL by 1mm, and 6mm on the XXL bikes. Small and medium Sentinel frames keep the same reach measurements, and all five sizes receive 5mm of additional chainstay for added high speed stability. The BB has come up by 1mm, while the seat tube above it is shorter across the size run to accommodate longer travel dropper posts and to allow shorter riders to buy longer bikes if they like. Size small bikes come with a 150mm dropper, mediums get a 180mm dropper, and a 210mm post comes on large-XXL sizes.

Seat tube angles are slightly steeper across the board, and the headtubes slackened by 0.4°. In short, it seems that the engineers at Transition were pretty stoked with this bike to begin with, and made a few final touches on their otherwise dialed design with this recent update.

Full carbon frame: Front triangle, rear triangle, and rocker.

According to Transition, “The 24% overall progression with a linear rate of change works well with air or coil shocks. The stock 62.5mm shock stroke provides 150mm of rear wheel travel, with the ability to use a 57.5mm stroke shock to get 140mm [of] travel and [a] large usable sag range [lets] you custom tailor your ride.”

Sentinel frames are available with three different builds, or as a customizable frame with a Fox Float X2 Performance Elite shock for $3,199. Top builds will come with a SRAM X01 drivetrain, Code RSC brakes, Fox 36 Performance Elite fork, a Performance Elite Float X2 shock, DT Swiss M1700 Spline 30 wheels, all retailing for $6,599. The mid-level bike runs on a SRAM GX drivetrain, Code RSC brakes, RockShox Lyric Ultimate RC2 fork, RockShox Super Deluxe Ultimate shock, and Stan’s Flow S1 Team wheels, prices at $5,499. Finally, the most affordable carbon Sentinel model gets a SRAM GX Eagle drivetrain, Code R brakes, RockShox Lyrik Select Charger RC fork, Super Deluxe Select+ RT damper, and a set of Stans Flow D rims laced to Novatech hubs, for $4,999. All three models grip with a Maxxis 2.5″ Assegai 3C EXO+ tread up front and a 2.4″ Minion DHR II 3c EXO+ out back. Head to the Transition Bikes website for further build details.

The new Sentinel is available in Ti Grey and Loam Gold at your local Transition dealer, at, or via the brand’s web store.