The Transition Sentinel is a fascinating bike. 140mm of rear wheel is paired with a 160mm fork and some of the most aggressive geometry we’ve seen to date for a bike consistently described as an absolute beast on the descents, keeping pace with bikes with more rear wheel travel. Keeping in line with current trends, the bike is longer and slacker with a steep 76.8º seat tube angle to help facilitate going up mountains.
The Sentinel pushes the envelope with a 64º head tube angle that’s close to inline with angles we’re seeing on current DH bikes. (My Norco Aurum has a 63º HA for comparison) Wheel flop is kept in check with the use of a reduced fork offset that also brings the wheel back in under the rider. (the Fox 36 has 44mm instead of 51mm)
The change in trail does more than change the chopper effect; it also helps keep weight on the front wheel when cornering at speed. In previous experiences on longer bikes, I had the weirdest crashes and lay downs I never experienced on other bikes, making this even more intriguing.
Formerly a 29″ naysayer, I’m no longer a skeptic when it comes to the subject of big wheels on mountain bikes — they shred, and under the right pilot, a 29er with good geo can do anything you need it to. A bike that descends like a DH bike but easily climbs back up for more? It turns out long travel bikes with 29″ wheels provide this experience, and after a season of tearing it up on a 5″ travel 29er, I’ve come to the conclusion that the slot in my quiver reserved for a long travel all mountain/enduro machine will feature big wheels.
I’ve always been a fan of how FSR rides on the trail, and though I have yet to log saddle time, I’m sold. We’re on the list for a Sentinel now; the main question — medium, or large? At 5’10” I’m between Transition’s recommended sizes, but the medium is already featuring a reach that’s 30mm longer than anything I’ve owned before. Being able to whip this thing around at speed is desirable…
Check it out at TransitionBikes.com
Online reviews of the Sentinel