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Today’s Deals2024 YT Industries
Jeffsy UNCAGED 13 MX
A 29″ / 27.5″ aluminum frame full suspension trail bike with high-end components.
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Manufacturer Price
$3,499| Weight | 34.2 lbs |
|---|---|
| Frame | Aluminum |
| Suspension | Full, 145 / 150mm |
| Fork | Marzocchi Bomber Z1 |
| Shock | Marzocchi Bomber |
| Wheels | 29″ / 27.5″ Aluminum |
| Drivetrain | 1 × 12 |
| Groupset | GX Eagle |
| Brakes | SRAM G2 Ultimate Hydraulic Disc |
| Seatpost | Dropper |
Based on build material and quality level of the frame, fork, wheelset, groupset, suspension system, and more.
Compare the full Jeffsy model range
View Comparison5'0" – 5'6"
5'3" – 5'10"
5'7" – 6'1"
5'11" – 6'5"
6'2" – 6'8"
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Summary
The YT Industries Jeffsy is a highly versatile trail bike that excels in both climbing and descending, offering a fun and agile ride. Its updated frame features internal storage and a sorted component package, making it a great value for the price. While it performs well on a variety of trails, some reviews note areas for improvement in stability and component durability.
Excellent ride-anywhere bike
Updated frame with internal storage
Sorted component package
Rides lighter than its actual weight
Versatile for both rowdy trail sessions and long days in the saddle
Matte black carbon finish is easily scratched and scuffed
Lacks stability at high speeds
SRAM SX Eagle drivetrain required regular adjustment
The new Jeffsy is an excellent trail bike package that can handle tougher stuff too.
Bike PerfectThe JEFFSY turns every trail into a round of Wild Mouse. No other bike in the test is this much fun.
Enduro Mountainbike MagazineThe YT Jeffsy Mk3 Core 4 is a capable all-mountain bike which, thanks to its spec, has a bias towards descending but is equally able to climb.
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Feb 2025
Calling these bikes “all-new” might be a stretch, but there's no denying the incredible value and versatility.
Nov 2024 · Nelson
With a value spec of workhorse components, and putting higher-end components where it matters, this is a hard package to beat.
Top-notch paint quality and finish
Cleanly designed internal cable routing
V4L suspension design for great traction and efficient climbing
SRAM SX Eagle 12-speed with a broad gearing range
SRAM G2 R brakes with adjustable reach levers
YT Postman 100mm dropper seatpost enhances riding experience
Maxxis DHR II tires for excellent cornering and traction
Great value with workhorse components and higher-end components where it matters
SRAM SX Eagle drivetrain requires regular adjustment
760mm-wide aluminum handlebar too wide for most kids
Significant seal friction in forks and shocks for lighter riders
Stiff 35mm aluminum handlebar may exacerbate feedback and control issues
Sep 2024
The YT Jeffsy Core 4 has excelled at being an all-round “grab and go” bike, regardless of what gets thrown in its way. Check out our review.
Aug 2024 · Cory Benson
YT’s newest limited edition Uncaged 14 build decks out their latest Jeffsy carbon trail bike with a killer paint job, a drool-worthy build, the first…
Jul 2024
The YT Jeffsy Mk3 Core 4 is a capable all-mountain bike which, thanks to its spec, has a bias towards descending but is equally able to climb. While the spec is hard to argue with and the value for money is excellent, it's worth paying attention to the frame sizing and geometry to get the ride you want. The bike could be improved further with a longer dropper post and a slacker head angle but YT has done a good job continuing to polish the already excellent Jeffsy.
May 2024 · YT Industries
Now, YT Industries takes it back to the 90s with a limited, retro-inspired Uncaged 13 edition, mixing things up with an MX-specific frame and custom, nostalgic silver components..
Mar 2024 · Ben Haworth
The YT Jeffsy Core 4 is a bike that arrives in a box that is not quite perfect out of the box. BUT... there is loads of potential here.
Oct 2023 · Robin Weaver
The new Mk III Jeffsy feels more capable but just as much fun as ever
Well-balanced geometry
Suspension feels active but supportive
Very capable on the terrain I tested it on
Freewheel pickup could be quicker
Front tyre not the best in soft mud
| Fork | MARZOCCHI BOMBER Z1, 29“ | 150 mm | GRIP | 15x110 mm | Gloss Red | 44 mm Offset Travel: 150mm Spring Type: Air |
|---|---|
| Shock | MARZOCCHI BOMBER AIR, 210 x 55 mm | 2pos-Adjust | CL RM | 0.6 Spacer Travel: 145mm |
| Bottom Bracket | SRAM DUB BSA, BB DUB BSA 73 MTB |
| Headset | CANE CREEK SERIES 40, ZS44 ZS56 | High Cap | 2 Spacer 5mm |
| Stem | RENTHAL APEX 35, 50 mm | +/-6° | Custom Silver |
| Handlebar | RENTHAL FATBAR 35, Width 780mm | Rise 30mm | 7° Back Sweep | 5° Up Sweep | 6061 AL | Custom Silver |
| Saddle | SDG BEL AIR 3.0, 140 mm I Lux-Alloy Rail I Uncaged Custom Design |
| Seatpost | YT POSTMAN V2, Ø 31,6mmI MMX-Remote | Adjustable drop 25/10/5mm | 125 mm (S) I 150 mm (M) | 170 mm (L) | 200 mm (XL) | 230mm (XXL) Type: Dropper |
| Grips | ODI VANS V2.1, Lock On | Red |
| Rear Derailleur | SRAM GX EAGLE, 12-speed |
|---|---|
| Crank | SRAM GX EAGLE, Crank Arm Length 170 mm | 32T |
| Shifters | SRAM GX EAGLE, 12-speed |
| Cassette | SRAM GX EAGLE, 10-52T | 12-speed |
| Brakes | SRAM G2 ULTIMATE, Polar Grey Anodized | Rotor CENTERLINE | Front 200 mm / Rear 200 mm Type: SRAM G2 Ultimate Hydraulic Disc |
| Rims | CRANKBROTHERS SYNTHESIS ENDURO 2 ALLOY - SILVER OE, Front: 29’’ 31,5 mm | 110 x 15 mm | 6-Bolt, Rear: 27,5’’ 29,5 mm | 148 x 12 mm | 6-Bolt | XD |
|---|---|
| Tires | FRONT: MAXXIS DHF I REAR: MAXXIS MINION DHR II, Front: Tire Size 29“ x 2.50 WT I EXO+ Casing I 3C MaxxTerra Compound I Tubeless Ready, Rear: Tire Size 27.5“ x 2.40 WT I EXO+ Casing I 3C MaxxTerra Compound I Tubeless Ready |
First added May 24
Last updated February 15
Not listed for 477 days