Our expectations of the Transition Sentinel Carbon were very high for this group test, not least because the guys and gals behind the brand are really good riders themselves. Its specs look extremely promising, but can the bike deliver on the trail?

For an overview of the test fleet head to the group test: The best enduro bike 2021 – 13 models in review

Transition Sentinel XT | 160/150 mm (f/r) | 14.80 kg in size L | € 5,799 €
Manufacturer’s website

The Transition Sentinel looks very promising just standing there. Its low-slung frame suggests that this bike likes to get rowdy. You get 150 mm travel at the rear paired with 160 mm travel up front. Like its predecessor, the new Sentinel rolls on 29″ wheels, but the new design looks a lot more futuristic with clean, straight lines and sharp angles. The rear suspension relies on a classic horst-link. The details of the frame make it clear that the boys and girls from Transition are riders themselves. The brake line is routed externally for easier assembly and the bottom bracket relies on the threaded BSA standard. With bosses on the top tube, you’ve also got on-bike storage options for a spare tube or tools. A particular highlight for us is the short and straight seat tube, allowing for a whopping 210 mm travel dropper post. Since Transition obviously know about the rattling Shimano pads, our test bike came equipped with regular pads that don’t have the cooling fins. Unfortunately, we still encountered an annoying rattle during the test, caused by the cables inside the frame – what a shame.

The components of the Sentinel Carbon XT – Reliable and proven

Instead of the flagship model, we received the € 5,799 Transition Sentinel XT for this test. Even so, there is almost nothing for us to criticise about the bike. The Shimano XT drivetrain and brakes are proven performers. Without the cooling fins, the pads don’t rattle, and the bite points were consistent on these models. The suspension consists of a FOX 36 Performance fork (without GRIP2) and an X2 air shock of the same range. Stan’s NoTubes ZTR Flow S1 rims match the quality of the remaining components. Our highlight? The 210 mm OneUp dropper post ensures maximum freedom of movement on the bike. The EXO+ casing on the MAXXIS tire combination is good for all-round use. However, if you want to let rip, you’d better switch to Doubledown models.

The rear end of the Sentinel barely uses its travel. As a result, the bike generates little traction and has to be ridden actively.
The externally routed brake line doesn’t necessarily give the bike the cleanest look but it makes it a lot easier to replace if necessary – that’s how it should be!
Transition rely on Shimano’s classic pads without cooling fins. That way the pads don’t rattle. It’s a shame that the cables aren’t as quiet.

Transition Sentinel XT

€ 5,799


Fork FOX 36 Performance GRIP 160 mm
Rear Shock FOX FLOAT X2 Performance 150 mm
Seatpost OneUp V2 210 mm
Brakes Shimano XT 4-piston 203/203 mm
Drivetrain Shimano XT/SLX 30 (10-51)
Stem ANVL Swage 40 mm
Handlebar ANVL Mandrel Alloy 35 800 mm
Wheelset Stans NoTubes ZTR Flow S1
Tires MAXXIS Assegai MaxxTerra EXO+/MAXXIS Minion DHRII MaxxTerra EXO+ 2.5"/2.4"

Technical Data

Weight 14.80 kg
Wheelsize 29"

The bosses on the top allow for a very easy and clean way to store a spare tube or tools on the bike. Nice!
No other bike in the test comes with a dropper post as long as that on the Transition. This is made possible by the short but straight seat tube. Brilliant!

The geometry of the Transition Sentinel – Modern, balanced, reasoned

The geometry of the Sentinel reads exactly as one would expect from a modern enduro bike. In size large the reach is 476 mm, the chainstays are 440 mm long, the head angle is 63.6° and the seat tube angle is 76.9°. Transition were one of the first brands to reduce the offset of their forks and that feature has also been carried over to the latest Sentinel. The only thing that stands out here is the somewhat meagre 29 mm bottom bracket drop.

Seat tube 350 mm 390 mm 430 mm 460 mm 490 mm
top tube 552 mm 585 mm 613 mm 641 mm 665 mm
Head tube 100 mm 110 mm 120 mm 130 mm 140 mm
Head angle 63.6° 63.6° 63.6° 63.6° 63.6°
Seat angle 78.2° 77.5° 76.9° 76.4° 76.0°
Chainstays 440 mm 440 mm 440 mm 440 mm 440 mm
BB Drop 29 mm 29 mm 29 mm 29 mm 29 mm
Wheelbase 1,199 mm 1,233 mm 1,263 mm 1,292 mm 1,316 mm
Reach 420 mm 450 mm 476 mm 501 mm 521 mm
Stack 613 mm 622 mm 631 mm 640 mm 649 mm
Helmet Bontrager Rally WaveCell | Glasses SCOTT Shield | Jersey Fox Ranger | Shorts Fox Ranger
Knee pads FOX Launch Knee Pad | Shoes FiveTen Freerider Pro

Efficient with a good riding position – The Sentinel performs on the uphill

This is exactly how an enduro bike should climb! The Transition does everything right on the climbs, offering a superbly balanced riding position and an efficient rear end. It marches forward efficiently and remains easy to control on technical terrain. The only thing we noticed was the front wheel flopping over slightly through very tight corners. Still, you can spare yourself the effort of reaching for the climb switch, ensuring you always have plenty of traction and allowing you to get up even trickiest sections with ease.

When the trail points downhill, the Sentinel motivates you to get active. Though the reach isn’t all that extreme, the Sentinel feels rather long and the front wheel is far in front of you.

A bike full of character – The Transition Sentinel challenges the rider downhill.

This is due to the slack head tube angle. As such, the Sentinel requires an active and determined riding style despite the long chainstays. If you’re not on the ball, the bike will understeer and you’ll carry on going straight. Provide the necessary input and the Sentinel will reward you for it. The suspension is very supportive and you can generate a lot of speed by pumping the bike. It loves popping off features on the trail and the rear end easily deals with even the harshest landings. Everywhere else, the bike isn’t very generous with its 150 mm travel. It gets unsettled on fast and big hits, requiring a certain riding style to stay on course. The frame’s stiffness also plays into this, meaning that the bike is quicker to be thrown off line over small bumps. As a result, it is better to jump over a rock garden with the Sentinel than to just plough through.

How does the Sentinel compare to the competition?

The Transition Sentinel and the Nukeproof Mega are very similar on paper, yet they are worlds apart. Thanks to its more capable suspension, the Nukeproof Mega is a lot more composed and faster in rough terrain. The Transition, on the other hand, is zippier and livelier. In direct comparison with the Ibis Ripmo, the Sentinel offers a little less traction, though it has significantly more reserves for hard compressions, such as when you send it too hard.

Tuning tips: dampen the noise of the cables in the frame

Riding Characteristics



  1. sluggish
  2. efficient


  1. cumbersome
  2. playful


  1. nervous
  2. confident


  1. demanding
  2. balanced


  1. harsh
  2. plush

Fun Factor

  1. planted
  2. poppy

Value for money

  1. terrible
  2. very good

Intended Use










The Transition Sentinel Carbon XT is a bike with a strong character. It climbs brilliantly and offers lots of pop and a playful character on the descents. However, it wants to be ridden actively. If you’re not fully invested, you’ll get punished for it, quickly overshooting the corners. On super rough tracks, the rear end can’t keep up and lacks traction, letting the competition pull away.


  • rewards an active riding style
  • lots of reserves for big impacts
  • excellent climbing characteristics


  • punishes a passive riding style
  • not enough traction in rough terrain
  • very stiff bike overall

You can find out more about at transitionbikes.com

The test field

For an overview of the test fleet head to the group test: The best enduro bike 2021 – 13 models in review

All bikes in test: Canyon Strive CFR (Click for review) | COMMENCAL Meta AM 29 Öhlins (Click for review) | GIANT Reign Advanced Pro 0 (Click for review) | Ibis Ripmo V2 (Click for review) | Nukeproof Mega 290 Alloy Pro (Click for review) | Propain Spindrift CF Mix Custom (Click for review) | Rocky Mountain Altitude Carbon 90 Rally Edition (Click for review) | Santa Cruz Megatower CC X01 Coil RSV (Click for review) | Santa Cruz Nomad CC X01 RSV (Click for review) | Specialized Enduro Expert (Click for review) | Specialized S-Works Stumpjumper EVO (Click for review) | Transition Sentinel XT | Trek Slash 9.8 XT (Click for review)

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Words: Photos: Christoph Bayer, Valentin Rühl, Markus Frühmann