At YT, the UNCAGED decal is exclusive to special models with a high-end spec. The same goes for the JEFFSY UNCAGED 6, which comes equipped with RockShox’s electronic Flight Attendant suspension system and other bling components. But how does YT’s high-tech machine fare on the trail?

For an overview of the test fleet head to the group test: The best trail bike of 2022 – 14 models in review

YT JEFFSY UNCAGED 6 | 150/150 mm (f/r) | 14 kg in size XL | € 8,999 | Manufacturer’s website

With the JEFFSY UNCAGED 6, YT are entering the race with the most expensive bike in their entire portfolio. Limited to 200 units worldwide, it costs € 8,999 and tilts the scales at 14 kg. The UNCAGED 6 flagship model comes equipped with RockShox Flight Attendant, which automatically adjusts the compression damping of the 150 mm fork and shock according to the riding situation.

The spec of the YT JEFFSY UNCAGED 6

The elegant carbon frame and swingarm are covered in protective tape, while a TPU plate shields the down tube from stray rocks and impacts. Moreover, a generously sized chain and seat stay protector prevents chain slap and paint chips. The horizontally-mounted shock doesn’t leave much room for a conventional cage, but YT’s in-house Thirstmaster 4000, which was developed specifically for the Jeffsy, fits snugly into the small space under the shock. This is the smaller Thirstmaster 600 ml model, which is attached to the frame via FIDLOCK’s magnetic holder. If you prefer a classic water bottle, the Jeffsy comes standard with an adapter for conventional bottle cages. The rear brake line is secured to the seat stay with zip ties – other manufacturers offer more elegant solutions here.

More grip, please!
YT is one of the few manufacturers in this test to use a front tire with the soft MaxxGrip rubber compound. We like it!
Safety First
The elegant frame of the JEFFSY is well protected.
Radio tower
The wireless components of the JEFFSY ensure a very tidy cockpit.


€ 8,999


Fork RockShox Lyrik Ultimate Flight Attendant 150 mm
Rear Shock RockShox Super Deluxe Ultimate 150 mm
Seatpost RockShox Reverb AXS 170 mm
Brakes SRAM G2 Ultimate 200/200 mm
Drivetrain SRAM XX1 Eagle AXS 1x12
Stem Renthal Apex 50 mm
Handlebar Renthal FatBar Carbon 780 mm
Wheelset Crankbrothers Synthesis Enduro Carbon 29"
Tires MAXXIS Minion DHF, 3C, MaxxGrip, EXO/MAXXIS Minion DHR II, 3C, MaxxTerra, EXO 2.5/2.4

Technical Data

Weight 14 kg

Tuning Tip: tires with robust casing, at least rear

Quattro amici
Make sure these four are always with you and fully charged or you’ll have a bad time riding.
Not good enough!
While big 200 mm brake rotors front and rear promise plenty of braking power the SRAM G2 Ultimate RSC can’t keep the promise.

RockShox’s electronic Flight Attendant suspension system recognises the riding situation and automatically adjusts the compression damping of the fork and shock, switching between Open, Pedal and Lock modes in the bat of an eyelid, depending on what you need at that moment. The suspension consists of a Lyrik Ultimate fork and Super Deluxe Ultimate rear shock. YT also rely on electronics for other components, combining a RockShox Reverb AXS dropper post and SRAM XX1 AXS drivetrain, which both ensure a tidy cockpit. However, at 170 mm, the dropper has too little travel, limiting the freedom of movement on the bike. Moreover, you’ll have to run an accurate charging schedule because the electronic components employ a total of 4 batteries. That being said, all electronic RockShock/SRAM components rely on the same battery, allowing you to swap them around in case you get stuck on the trail. SRAM also supply the G2 Ultimate brakes which, despite running on big 200 mm rotors front and rear, generate too little braking power for a trail bike. We recommend upgrading to more powerful stoppers, like SRAM’s CODE RSCs or Shimano’s XT 4-piston stoppers.

Nearly-hardtail feeling
Uphill, the electronic suspension system ensures an efficient ride.

The cockpit consists of a Renthal Apex stem and 780 mm FatBar carbon handlebars. The Crankbrothers Synthesis Enduro Carbon wheelset was designed with compliance in mind and is meant to offer more comfort on the trail and feel like a lightweight alloy wheelset – albeit without the vague handling characteristics. For the tires, the Germans rely on MAXXIS, combining a Minion DHF with soft MaxxGrip rubber compound at the front and Minion DHR II in the harder MaxxTerra compound at the rear. This setup ensures increased cornering traction but doesn’t affect rolling resistance too heavily, as most of the weight is on the rear tire. Although the advantages of this combination clearly outweigh its disadvantages, YT is one of the few manufacturers to rely on it. Unfortunately, both tires come in the puncture-prone EXO casing. We recommend running a tire with more robust casing, like MAXXIS DoubleDown, at least at the rear. This will protect the carbon rims against nasty impacts while allowing you to run lower tire pressures for more traction.

The stock SRAM G2 brakes get easily overwhelmed on a bike like the JEFFSY, robbing you of confidence on descents.

The geometry of the YT JEFFSY UNCAGED 6

The JEFFSY UNCAGED 6 is available in 5 sizes, S to XXL. While the YT is the only bike with an XL frame in this test, the 490 mm reach is relatively short compared to most of its opponents, blending in perfectly with the rest of the test field at. At 460 mm, the long seat tube restricts the freedom of movement on the bike. A flip chip in the shock mount allows you to alter the geometry of the Jeffsy. In the high setting, the seat and head angle are 0.5° steeper while the bottom bracket is 8 mm higher. Chainstay length is 435 mm in sizes S to L and grows by 5 mm in XL and XXL, providing consistent handling across all sizes.

size S M L XL XXL
Seat tube 400 mm 415 mm 435 mm 460 mm 485 mm
Top tube 572 mm 593 mm 615 mm 638 mm 660 mm
Head tube 100 mm 105 mm 110 mm 125 mm 125 mm
Head angle 66° 66° 66° 66° 66°
Seat angle 77° 77° 77° 77° 77°
Chainstays 435 mm 435 mm 435 mm 440 mm 440 mm
BB Drop 32 mm 32 mm 32 mm 32 mm 32 mm
Wheelbase 1174 mm 1196 mm 1218 mm 1247 mm 1269 mm
Reach 430 mm 450 mm 470 mm 490 mm 510 mm
Stack 618 mm 622 mm 627 mm 636 mm 640 mm
Helmet Fox Speedframe | Glasses Melon Optics Kingpin | Backpack USWE Shred16 | Jersey POC Rouse Shirt | Pants Fox Defender Shorts | Kneepad Chromag Rift | Shoes Ride Concepts Hellion Clip | Socks iets frans | watch Garmin Forerunner 945

The YT JEFFSY UNCAGED 6 on the trail

When making your way to the trail centre on level ground, the YT JEFFSY puts you in a slightly stretched riding position with a fair amount of pressure on the hands. As soon as you start climbing towards the trailhead, the front lifts off the ground easily, causing the front wheel to lose traction. Thanks to the electronic RockShox Flight Attendant system, the suspension is firm and always sits high in its travel. As a result, the rear suspension is pedal-neutral, efficiently transferring the power from your legs to the rear wheel. That being said, there are other bikes in this test that are just as pedal-neutral even without an electronic suspension system and that are a lot lighter too. All in all, Flight Attendant doesn’t bring many advantages to the trail with the YT.

The YT JEFFSY UNCAGED 6 offers precise handling and yet is compliant enough to forgive small riding mistakes.

Hold on tight!
In rough trail sections, the YT calls for a sporty riding style.

On steep descents, the JEFFSY UNCAGED 6 impresses with direct and precise handling and yet offers enough compliance to bail you out if you get yourself into a pickle with messy lines and dodgy weight shifts. That being said, the JEFFSY still requires a sporty riding style because the firm rear suspension passes on plenty of feedback to the rider, requiring more physical effort in rock gardens and root carpets to compensate for the impulsive character of the bike. The high saddle is a real bummer because the long seat tube together with the relatively short dropper post restricts freedom of movement on the bike, robbing you of confidence on steep and technical trail sections.

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 YT JEFFSY UNCAGED 6 comes equipped with high-end components including an electronic suspension system. Unfortunately, other components like the brakes and tires don’t do justice to the character and intended use of the bike while the high seat tube restricts freedom of movement downhill. Flight Attendant definitely brings some advantages uphill but still doesn’t make the YT the best climber in this test. Downhill, the YT is stiff and direct, requiring a sporty and active riding style.


  • clean look
  • solid climber
  • direct and precise handling


  • brakes lack power
  • limited freedom of movement (due to long seat tube and short dropper post)

You can find out more about at

The test field

For an overview of the test fleet head to the group test: The best trail bike of 2022 – 14 models in review

All bikes in test: Atherton AM.150 (Click for review) | Bold Linkin 135 Ultimate (Click for review) | Canyon Spectral 125 CF 9 (Click for review) | Canyon Spectral CFR (Click for review) | FOCUS JAM 8.9 (Click for review) | Mondraker Raze RR SL (Click for review) | Propain Hugene (Click for review) | Rocky Mountain Instinct C70 (Click for review) | ROSE BONERO 3 (Click for review) | Santa Cruz Bronson CC X01 AXS (Click for review) | SCOR 4060 ST GX (Click for review) | Specialized Stumpjumper EVO S-Works (Click for review) | Specialized Stumpjumper EVO Elite Alloy (Click for review) | YT JEFFSY UNCAGED 6 (Click for review)

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Words: Simon Kohler Photos: Peter Walker, Mike Hunger

About the author

Simon Kohler

​​Simon loves speed. He has many years of racing experience as a longboard downhill skater, blasting down alpine passes on his board. In the meantime, he’s swapped four wheels for two, charging down trails and bike park lines aboard his mountain bike instead. He’s savoured some of Europe’s finest trails on various road trips through the Alps. Having lived in Austria for some time, he knows the local Austrian bike parks like the back of his hand. He’s a tech nerd through and through, using the skills and know-how from his engineering degree and his attention to detail to put the latest bikes and components through their paces for our reviews. As an early riser and self-declared muesli connoisseur, he lives his life powered by oats and the strength of his legs.