Transition Sentinel Review – 63.6 degrees — that’s a pretty nice temperature for riding your bike. It’s also where I’d like to set my AC but my wife claims she’d freeze to death at that point. Marital problems aside, we’re not talking about temperature here. 63.6 degrees is the slackest head tube angle I’ve ever ridden. Coincidentally, it’s the head tube angle of the Transition Sentinel V2. Just going off this number, it would be easy to pigeonhole the Sentinel into the enduro/couch/big pig category. I wouldn’t blame you for doing that — I did the same thing before I rode it. I think it’s a little more well-rounded than it may seem at first glance.

Transition sentinel Geometry

Let’s get into some of the other numbers here. While the Transition Sentinel has a 63.6-degree head tube angle, it has a steep 76.4-degree seat tube in the XL I tested. The reach is long and roomy at 501mm. The chainstays are a moderate 440mm. Put those numbers together and you’re left with a 1292mm wheelbase — long, but keep in mind we’re seeing some XLs over 1300mm these days. The numbers that seem to throw most folks off are the travel lengths — 150mm rear and 160m front. Most people just assume it’s 2495mm front and back — or so it seems. I believe the travel numbers combined with the slack geo are what make this bike so unique. 

Have you ever heard someone rant and rave about the way a short travel bike rides? They like to tell you the short travel keeps it lively, while the aggressive geometry lets you ride it hard (I’m sure you’ve heard me say the same thing). The Transition Sentinel applies that same idea in a slightly longer travel package. Take that Tallboy, Optic, or Spur, and shift it up the burly scale a few notches. The Sentinel has less travel than most other bikes with a 63.6-degree head tube angle. The long and stable geometry has your back when you run out of talent, but the shorter travel keeps it fun, lively, and engaging.

Transition sentinel review

Uphill

Let’s start with the hard part — going uphill. The Transition Sentinel plants itself right in the middle of the pack. It’s not the fastest climber, but it’s also far from the worst. It doesn’t feel overly excited to get to the top of the hill. To be fair, I rarely feel that way myself. It doesn’t feel like it’s holding you back, though. It just does the job without making too much fuss. 

The climbing position is rather comfortable and upright. It did take me a little bit to get used to the super slack front end. The front wheel is way out in front of you and tends to have a mind of its own when the trail gets steep. It takes a bit of wrestling on steep switchbacks to keep it going where you want it to go. One section of my test track in particular had a few tight and steep back-to-back switchbacks. I made it up them just fine, but it took maximum concentration. I’ve learned to shift forward and really drop my chest to the bars on the steepest turns.

The suspension platform finds a sweet spot between efficient and grippy. It feels a lot like a Santa Cruz Hightower in this department. It’s a little more active than some other platforms, but the traction and control on bumpy climbs are second to none. After some tuning, I landed on exactly 29.979% sag. At that sag, the suspension platform strikes a good balance between comfort and efficiency. My test loop has a particularly technical and rooty climb trail. In years past, I’ve struggled to clean the entire climb without dabbing. I’ve now ridden it four times aboard the Sentinel and I’ve yet to dab — I credit the rear wheel traction. Now, you might find yourself saying, “Doesn’t traction come from the tires?” Well, yes, traction comes from the tires, but if your bike can’t keep those tires on the ground, they’re not going to do you much good, are they?

Downhill

Now we can talk about the fun part — going back downhill. The very first thing you notice on the Sentinel is how quiet it is. I don’t know how it works, but it’s so quiet you can hear the silence — it’s magic. The only sounds coming from the bike are the buzzing hubs and the tires digging into the dirt. 

That silence translated to the ride quality too. It’s on the plusher end of the spectrum as far as all-mountain bikes go. The suspension feels deep and bottomless without making the bike ride like a pig. I don’t know exactly how Transition does it. It’s incredibly smooth off the top and starts ramping up quite a bit. At 24% progressive, the Sentinel ramps up quite a bit. That means it will work well with a coil shock. However, I don’t feel like it really needs a coil. Even with the air spring, it feels buttery smooth on the initial stroke. It actually has better small bump performance with the air shock than a lot of other bikes with coil shocks. My test track was pretty steep, rough, and rooty. The Sentinel did a great job of staying on the ground and under control even when pushing the pace through the bumps. It doesn’t skip around or get knocked off line much at all. 

I think the ramp-up and mid-stroke support is what gives the Sentinel its lively and engaging ride quality. With a supportive suspension platform, it is easy to get the bike off the ground. A little effort goes a long way with bunnyhops. I surprised myself a couple of times with how easy it was to get the bike in the air. It also feels very responsive to rider input. It goes exactly where you want it to without any vagueness often accompanied by longer travel bikes. I think that’s where the magic of the slack geo and moderate travel combo comes into play. 

The Sentinel has less travel than most bikes with geometry this slack. In fact, it seems that most folks overestimate how much travel it actually has. The general consensus of interested customers at the shop is “Man. That’s too much bike to pedal around.” I’m here to convince you otherwise. On paper, it looks like a lot of bike. Throw a leg over one, however, and you’ll quickly realize how mild-mannered it really is. Except it not at all mild-mannered when you start getting aggressive with it. Have I completely lost you here? I guess what I’m saying is that the Sentinel doesn’t ride like a full-on plow bike. It’s incredibly planted and confident, yet in an engaging and fun way. It allows you to ride the trail and be an active pilot while still being there to erase mistakes and cover your butt when you start writing checks your skills can’t cash.

One thing you need to know about this bike is it needs to be ridden with your weight centered. No off-the-back lollygagging here. You aren’t going to like how it feels if you’ve got your arms fully stretched out and your butt dragging on the back tire (read: poor form). You’ll swing too wide in the corners and that front end is going to feel too light. Ride it like you mean it, and the Sentinel comes alive. It allows you to slam into corners and rocket out the other side — even rough and bumpy corners without much support. You can wrestle the bike through the toughest ruts and berms at pace. When you drop the anchor right before a nasty corner, the bike sits down and digs into the dirt — hard. It reminds me of watching a DH bike slow down easily where trail bikes end up skidding all over the place.     

I want to touch quickly on a few changes I made to the stock build. I made sure to get a handful of rides in before swapping anything significant for the sake of being fair. The biggest change I made was swapping out the stock Rockshox Lyrik with a Zeb. I didn’t change travel lengths or anything — I stuck with 160mm for the new fork. As far as I can tell, the Zeb doesn’t seem to make a huge difference in terms of apparent stiffness. I feel like the support from the damper is incredible, though. Like the Lyrik, it feels very good in the initial stroke. Once you get deeper into the travel, however, it really starts to shine. The best way to describe it is it feels firm, without being harsh. It doesn’t blow through the midstroke and hit a harsh ramp-up at the end. Instead, it feels consistently supported the entire way through the stroke. The bottom-out feels pretty gentle and smooth. The first time out with the Zeb I had about 5-6 PSI less than I should. The fork would dive on the steeps and corners. I found bottom quite a few times, but I never once had one of those harsh clangs where both your wrists feel like they’re going to snap like toothpicks. I added the few PSI I needed and now I have nothing but good things to say about the Zeb. The Sentinel is very slack and requires you to ride centered over the bike, rather than off the back. A firm, supportive fork is a must for riding the bike aggressively. Plus the machined crown looks like it was made for the angular design of the Sentinel.

Call me a fanboy, but I really can’t find anything to complain about with the descents on the Sentinel. It’s a perfect match for me and my riding style. Looking back on my favorite bikes over the years, they pretty much all have 150mm/160mm of travel. It’s no surprise I like the Sentinel. I’m just surprised with how quickly it rose to the podium of my favorite bikes list.

Who is the transition sentinel for?

I think the Sentinel is far more well-rounded than most folks assume or give it credit for. I’d plop it right in the all-mountain category. Sure, it’s probably the most aggressive all-mountain bike you can buy, but I don’t feel like it’s “too much bike.” I’d easily categorize it with the Hightower, Ripmo, SB130 LR, and Norco Sight. I don’t think it fits in with the enduro-specific bikes — It’s far more lively and playful.  

So, the Sentinel is the perfect bike for people who fancy themselves trail riders. I’d say it leans more to the aggressive DH side than the Ripmo and Hightower, but not by much. It’s happy enough on smoother trails, even though it craves rough and rocky. What I’m saying here, is it’s a good option for anything you can throw at it.

If you want to climb the fastest, look elsewhere. If you want to get to the top, turn around, and have an absolute blast on whatever trail you take to the bottom (easy or hard), look no further.

Cons

• Doesn’t clear a 32-tooth oval chainring (clears up to a standard 32-tooth for people who enjoy knee pain) 
• If you’re going to make me pick another con, I’ll say something non-committal like “water pools up under the lower shock mount” — something lame like that.

Pros

• Great geometry and suspension design
• Looks that can kill (insert drool emoji here)
• Smart component selection
• Bosses under the top tube for tools
• Runs over large marmots with ease – watch the video