Bikes up to 60% offWe monitor over 40,000 bikes daily to find the best prices
Today’s Deals2023 YT Industries
Jeffsy CORE 4 29
A 29″ carbon frame full suspension enduro bike with ultra high-end components.
Compare the full range
Manufacturer Price
$4,999| Weight | 31.6 lbs |
|---|---|
| Frame | Carbon |
| Suspension | Full, 150 / 150mm |
| Fork | Fox Factory Float 36 |
| Shock | Fox Float X Factory |
| Wheels | 29″ Aluminum |
| Drivetrain | 1 × 12 |
| Groupset | Truvativ Descendant Carbon, X01 Eagle |
| Brakes | SRAM G2 RSC 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"
5'4" – 5'10"
5'8" – 6'1"
5'11" – 6'5"
6'3" – 6'8"
None yet.
Do you have this bike? Help other riders make a decision about which size will work for them by sharing your own size and fit notes.
Summary
The YT Industries Jeffsy is a highly capable and versatile enduro bike, praised for its gravity-hungry nature, fast and confident riding, and exceptional value. It excels in both climbing and descending, with a suspension system that offers great traction and support. The bike is often compared to top models like the Santa Cruz Hightower and Canyon Spectral, standing out for its playful yet stable handling.
Incredibly capable and fun
Exceptional value
Modern geometry
Great suspension performance
Versatile for all-mountain riding
Pedal bob on long climbs
Limited water bottle space
Underpowered brakes on some models
Press-fit bottom bracket issues
Somewhat vague-feeling climbing characteristics
The YT Jeffsy turned our usual value conversation on its head.
BetaWith the YT Jeffsy Base 29, you get an incredibly capable bike at an exceptional value.
BIKE MagazineThe Jeffsy is an excellent jack of all-mountain trades.
Bike PerfectThis is about as close as you can get to the ‘one bike for all’ ideal for how a lot of modern mountain bikers ride.
BikerumorThe new Mk III Jeffsy feels more capable but just as much fun as ever
BikeRadarFeedback?
View all reviews
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
Aug 2024 · Rich Owen
Rich Owen was a big fan of the previous Jeffsy, so what does he think of the latest Core 4 version after months of using it as his daily driver?
Excellent ride-anywhere bike
Updated frame with internal storage
Sorted component package with wireless SRAM T-Type drivetrain
Rides lighter than its actual weight
Useful internal and external on-bike storage
Matte black carbon finish is easily scratched and scuffed
Not the biggest internal storage opening
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.
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.
Jan 2024 · Simon Kohler
How did the YT JEFFSY CORE 5 fare in our big 2024 trail bike group test?
Trail bike with fun guarantee
Mind-boggling price/performance ratio
Super intuitive handling
Pure agility!
Countless clever frame details
No storage compartment on the alloy model
Jan 2024 · Dario DiGiulio
The Jeffsy boasts easy, intuitive handling, and now has in-frame snack storage.
Intuitive and easy handling
Active, grippy suspension feel
Quality frame with well-executed storage and accessories
Requires attention in very rough terrain
Some may wish for more supportive suspension
Stock frame storage bags could be improved
Nov 2023 · Cory Benson
Review: All-new YT Jeffsy reminds us that trail bikes are what we all love about mountain biking, from singletrack to bikeparks…
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 | FOX 36 FLOAT FACTORY, 29“ | 150 mm Travel | Grip 2 | 110 x 15 mm Axle | 44 mm Offset Travel: 150mm Spring Type: Air |
|---|---|
| Shock | FOX FLOAT X FACTORY, Shock Length: 210 mm | Shock Stroke: 55 mm ≙ 150 mm Travel | 2-way Adjustable Low-Speed Compression, Adjustable Rebound and Air Pressure, Kashima Coating Travel: 150mm |
| Headset | ACROS AZX-576, ZS44 ZS56 | High Cap | 2 Spacer 5 mm |
| Stem | RENTHAL APEX 35, 50 mm |+/-6° | Black/ Gold |
| Handlebar | RENTHAL FATBAR 35, 780mm | 30mm Rise | 7° Back | 5° Up | Custom Black |
| Saddle | SDG BEL AIR 3.0, YT Custom | Width 140 mm |
| Seatpost | YT POSTMAN MMX Remote, Ø 31.6mm | 125 mm (S-M) | 150 mm (L) | 170 mm (XL-XXL) Type: Dropper |
| Grips | ODI ELITE MOTION V2.1, Lock-On |
| Rear Derailleur | SRAM X01 EAGLE, 12-speed |
|---|---|
| Crank | SRAM Descendant Carbon, Crank Arm Length 175 mm | 32T I DUB-PressFit |
| Shifters | SRAM X01 EAGLE, 12-speed |
| Cassette | SRAM XG1295 EAGLE, 10-52T | 12-speed |
| Brakes | SRAM G2 RSC, Rotor CENTERLINE Ø front 200 mm / rear 200 mm | Adjustable Bite Point and Reach Type: SRAM G2 RSC Hydraulic Disc |
| Rims | CRANKBROTHERS SYNTHESIS ALLOY I9, 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 |
|---|---|
| Tires | MAXXIS MINION DHR II, Tire Size 29“ x 2.4 | EXO Casing | Tubeless Ready | 3C MaxxGrip EXO TR | 3C Maxx Terra EXO TR |
First added April 27
Last updated October 21
Not listed for 960 days