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Today’s Deals2025 YT Industries
Jeffsy Primus 24
A 24″ aluminum frame mountain youth bike with high-end components and sram g2 r hydraulic disc brakes.
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Manufacturer Price
$2,299| Weight | 27.8 lbs |
|---|---|
| Frame | Aluminum |
| Suspension | Full, 130 / 130mm |
| Fork | Manitou Machete JUNIT |
| Shock | Manitou |
| Wheels | 24″ Aluminum |
| Groupset | X1, NX |
| Brakes | SRAM G2 R 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 ComparisonSummary
The YT Industries Jeffsy is a versatile mountain bike that excels in agility and suspension performance, offering a fun and reliable ride across various terrains. It stands out for its value, with high-quality specs and thoughtful frame details, though some may find its weight and component choices limiting. The bike's geometry and suspension are praised for their balance and capability in both climbing and descending.
Super fun to ride
Excellent suspension
Highly agile
Most affordable bike in the test
Exceptionally quiet ride
Spec could be improved
Heavier than some competitors
Shorter dropper post limits freedom of movement
The YT JEFFSY is the only bike in this test that has already proven itself in a previous comparison.
Enduro Mountainbike MagazineDespite the top-tier spec, the JEFFSY CORE 5 remains the most affordable bike in this test.
Enduro Mountainbike MagazineThe Jeffsy feels like the triumphant return of the real-value trail bike.
Mountain Bike ActionFeedback?
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Apr 2025 · Simon Kohler
In our 2025 big trail bike comparison test, we pitted the YT JEFFSY CORE 5 against the hottest bikes of the season. How did it fare against the competition?
Super fun to ride
Excellent suspension
Highly agile
Most affordable bike in the test
Spec could be improved
Feb 2025
Calling these bikes “all-new” might be a stretch, but there's no denying the incredible value and versatility.
Feb 2025 · YT Industries
The Jeffsy range gets the Core treatment, with six options to suit most riders' needs.
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 · 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.
| Fork | MANITOU MACHETE JUNIT Travel: 130mm |
|---|---|
| Shock | MANITOU MCLEOD Travel: 130mm |
| Bottom Bracket | BB DUB BSA 73 MTB |
| Headset | ACROS AZX-576 |
| Stem | SDG JR |
| Handlebar | SDG SLATER |
| Saddle | SDG FLY JR |
| Seatpost | YT POSTMAN V2 Type: Dropper |
| Grips | SDJ SLATER JR |
| Rear Derailleur | SRAM NX |
|---|---|
| Crank | SRAM X1 |
| Shifters | SRAM NX |
| Cassette | SRAM PG1130 |
| Brakes | SRAM G2 R Type: SRAM G2 R Hydraulic Disc |
| Rims | SUNRINGLÉ DUROC 30 |
|---|---|
| Tires | FRONT: MAXXIS MINION DHF I REAR: MAXXIS MINION DHR II |
First added February 25
Last updated April 12
Not listed for 421 days