A 29″ carbon frame full suspension enduro bike with ultra high-end components. Compare the full range
1 × 12 — 12 speed
Jeffsy Uncaged 8 29
The Jeffsy Uncaged 8 29 is easier to ride up hills than similar bikes.
Similar bikes won‘t keep up with the Jeffsy Uncaged 8 29 while riding downhill or sprinting.
Based on build material and quality level of the frame, fork, wheelset, groupset, suspension system, and more. Learn more »
The YT Jeffsy 29 Core 3 is a very capable all-mountain bike which can handle the rough stuff but is equally at home on flow trails and jumps. While the specification list is solid for the money, it's worth paying extra attention to frame sizing and geometry to get the ride you want. With a longer dropper and some tougher tyres this bike has what it takes to be a real challenger when it comes to the best mountain bikes.
Aug 2022Read Review
Like Robocop or the Six Million Dollar Man, YT have rebuilt the Jeffsy with top notch tech to be (even) better than it was before
Aug 2022Read Review
In our 2022 trail bike group test, the YT JEFFSY 6 stands up against the competition with an electronic RockShox Flight Attendant suspension system.
Direct and precise handling
Brakes lack power
Limited freedom of movement (due to long seat tube and short dropper post)
Jul 2022Read Review
An excellent complete package that makes fun of all but the gnarliest descents, thanks to a head angle that feels too steep
Predictable ride quality
A solid suite of parts
Great for riding just about any terrain
Conservative head angle
A good price, but the outrageous value YT’s reputation was built on isn’t there
May 2022Read Review
Following the recent release of YT's Capra and Decoy MX Uncaged 9 builds is the trail-friendly 150mm Jeffsy Uncaged 8.
Apr 2022Read Review
YT’s contender for best trail bike on the market is the acclaimed Jeffsy, and the flagship bike in the Jeffsy line is the Uncaged 6. Why uncaged? Well, not only is it YT’s maxim on how to live life, the Uncaged tag helps distinguish this special edition model from the Core bikes that make up the rest of the range. So what makes Jeffsy Uncaged 6 so standout? For starters, it gets the brand new RockShox Flight Attendant electronic suspension, that automatically toggles the suspension settings on the fork and shock between open, pedal and lock modes based on the pitch of the bike, suspension data from accelerometers on the fork and shock, and whether or not you are pedalling. And, just like the SRAM XX1 AXS drivetrain and the RockShox Reverb AXS dropper post adorning the Uncaged 6, everything is wireless so it can in theory be fitted to any bike as a kit because unlike Fox’s Live Valve there are no dedicated mounts or cable routing required. And because it’s all designed under one roof, the derailleur, seat post, shock and fork use the same battery and charger. So let’s say your dropper post runs out of juice mid ride, simply swap the battery with the shock which then defaults to the open setting and continue as normal. Only the crank sensor uses a AAA battery, which SRAM says should last for a year before needing replacing. The Control Module on the fork is the brain and user interface of the system, but you can also make all of the adjustments through the SRAM AXS app. You can control the bias of the suspension, with five settings: that run for more open to firmer. So if you have a bike that uses a suspension system that is designed for pedalling efficiency, you’d run the bias more open. You also use the Control Module or the app, to electronically adjust the low speed compression damping on both the fork and shock, while air pressure and rebound damping in are adjusted the old fashioned way. Based around the same full carbon Jeffsy frame that comes on the Core 4, the Uncaged 6 boasts 152mm of rear travel in the high geometry setting and 147mm in the low position. Where YT splits the difference and calls it a 150mm bike. But just like the alloy Jeffsy Core 2 that we featured in our Trail Bike of the Year test, we measured rear travel at 140mm in the low setting, so 7mm shy of claimed. The suspension is so well tuned though, that you never feel under gunned. Suspension If the addition of Flight Attendant isn’t enough to get your pulse racing, how about the latest fork tech? The new RockShox Pike, Lyrik and Zeb Flight Attendant equipped forks now feature Pressure Relief Valves on the back of the lower legs for blowing off steam, just like the latest Fox forks. It’s what’s inside the 150mm travel Lyrik Ultimate on the Jeffsy …Continue reading »
Best of both worlds suspension thanks to Flight Attendant
Every bike doesn’t come with Flight Attendant
Feb 2022Read Review
A great value with an appetite for rowdier trails. .
Pedal bob had us using the lockout on long climbs
Slightly limited water bottle space
Could use stronger brakes
Dec 2021Read Review
The YT Jeffsy 29 Core 4 is a versatile all mountain bike that’ll happily crunch out mellower miles or tackle some tough enduro tracks.
Oct 2021Read Review
5'0" – 5'6"
5'4" – 5'10"
5'8" – 6'1"
5'11" – 6'5"
6'3" – 6'8"
CANE CREEK HELM MK2, 29“ | 150 mm Travel (extendable up to 160 mm) | 44 mm Offset | Adjustable High- and Low-Speed Compression and Lowspeed Rebound
CANE CREEK KITSUMA AIR, Shock Length 210 mm | Stroke 55 mm ≙ 150 mm travel | 3-Pos Climb Switch | Adjustable High- and Low-Speed Compression and High- and Low-Speed Rebound | Twin Tube
CANE CREEK Hellbender 70, ZS44 ZS56 | Stainless Steel Bearings I 2 Spacer 5 mm
RENTHAL APEX 35, Length 50 mm | 35 mm Clamp | Rise +/- 6°
RENTHAL FATBAR 35, Width 780 mm | Rise 30 mm | 7° Back Sweep | 5° Up Sweep | Custom Black
SDG BEL AIR 3.0, YT Custom | Width 140 mm | Lux-Alloy Rail
SRAM REVERB AXS, Ø 31.6 mm | 125 mm Drop (Frame Size S-M) | 150 mm Drop (Frame Size L) | 170 mm Drop (Frame Size XL-XXL) | MMX-Remote
ODI ELITE MOTION V2.1, Lock On
SRAM GX EAGLE AXS, Wireless | Instant Activation | 12-speed | Battery Protector
SRAM GX Eagle, Crank Arm Length 175 mm | 32T | DUB
SRAM GX EAGLE AXS CONTROLLER, 12-speed | Right
SRAM XG 1275 EAGLE, 10-52T | 12-speed
SRAM G2 RSC, Rotor CENTERLINE Ø front 200 mm / rear 200 mm | adjustable Bite Point and Reach
CRANKBROTHERS SYNTHESIS ENDURO ALLOY , Front: Aluminum Rims 29“ | Inner Width 31,5 mm | Hub 110 x 15 mm | Rear: Aluminum Rims 29“ | Inner Width 29,5 mm | Hub 148 x 12 mm | Freehub I9 1/1 XD
FRONT: MAXXIS MINION DHF I REAR: MAXXIS MINION DHR II, Front: Tire Size 29“ x 2.5 WT | EXO Casing | 3C MaxxGrip Compound | Tubeless Ready | Rear: Tire Size 29“ x 2.4 WT | EXO Casing | 3C MaxxTerra Compound | Tubeless Ready