YT Industries Jeffsy Core 4 CF 29

Name: YT Industries Jeffsy Core 4 CF 29
Brand: YT Industries

2025 MountainTrail Manufacturer page

Last known price: $5,999

Prices shown first for United States
Travel: 150 / 145 mm Fork / rear shock
Wheels: 29″
Drivetrain: 1 × 12 32t / 10–52t
Gear range: 520%
Weight: 14.6 kg 32.2 lb · Reference configuration not specified
Frame: Carbon
Brakes: Hydraulic disc

Rider height by size (cm)

Size guide

SM 153–166
MD 162–176
LG 172–185
XL 181–194
XXL 190–203

Components

16 of 16 identified

Parts found in a manufacturer catalog show their brand, model and key numbers, and the steps show how precisely they are identified: brand, series, model, or the exact product. The info button has every detail and the text the manufacturer published.

Suspension

2 parts

Drivetrain

5 parts

Bottom bracket
- SRAM
Cassette
- SRAM 10–52t
Crankset
- Truvativ Chainring Guards 32t
Rear derailleur
- SRAM X0
Shifters
- SRAM

Brakes

1 part

Brakes
- Hayes

Wheels and tires

2 parts

Cockpit and contact points

6 parts

Sizes and geometry

5 sizes Open in the geometry plotter

Enter your height to highlight matching ranges.

Size LG

Table

Reach 481mm

Stack 622mm

Wheelbase 1236mm

Head angle 65.6°

Seat angle 78.5°

Every size is drawn to the same scale, in millimeters. Explanatory schematic on an assumed 29″ wheel; exact published values are in the table below.

Size Reported by the manufacturer

Complete manufacturer geometry table 5 published sizes

Complete manufacturer geometry by size
Measurement
Reachmm	442	462	481	501	521
Stackmm	608	615	622	629	636
Top tube lengthmm	562	585	607	630	652
Seat tube lengthmm	385	410	435	460	485
Head tube lengthmm	100	108	116	124	132
Head tube angle	65.6°	65.6°	65.6°	65.6°	65.6°
Seat tube angle	77.5°	78.1°	78.5°	78.9°	79.2°
Chainstay lengthmm	435	435	435	440	440
Wheelbasemm	1189	1213	1236	1265	1288
Front centermm	755	779	802	826	849
Bottom bracket dropmm	25	25	25	25	25
Bottom bracket heightmm	351	351	351	351	351
Standover heightmm	738	736	740	746	750
Fork rakemm	44	45	45	46	46
Trailmm	122	120	120	119	119
Stack/reach ratio	1.38	1.33	1.29	1.26	1.22

Not published by the manufacturer: Front travel, Rear travel, Crank length, Handlebar width, Stem length, Stem angle, Seatpost length and Dropper post travel.

Specifications

Frame and fork

Intended fit: Unisex
Frame material: Carbon
Bicycle weight: 14.6 kg

32.2 lb

Suspension

Suspension configuration: Full suspension
Front travel: 150 mm
Rear travel: 145 mm

Drivetrain

Derived by Bikelake

Front chainrings: 1
Smallest chainring: 32
Largest chainring: 32
Rear sprockets: 12
Smallest sprocket: 10
Largest sprocket: 52
Lowest gear: 17.9 in
Highest gear: 92.8 in

Wheels and brakes

Wheel configuration: Same size
Brake type: Hydraulic disc

Fit and controls

Derailleur hanger: UDH
Seatpost: Dropper seatpost
Shifting: Electronic

Additional specifications

Bottom bracket standard: BB86/BB92
Fork spring: Air
Wheel material: Carbon
Wheel size: 29″

Technical analysis

4 measures

How these figures sit among bicycles of the same class and model year. Context, not a ranking.

Front travel

150 mm

This value is above the central range for this class.

Cohort: Mountain / Trail Model year: 2025
Sample: 1,810 bicycles with this information
Coverage: 97.5% of the class

Lowest gear

17.9 gear inches

This value is within the central range for this class.

Cohort: Mountain / Trail Model year: 2025
Sample: 1,384 bicycles with this information
Coverage: 74.6% of the class

Highest gear

92.8 gear inches

This value is within the central range for this class.

Cohort: Mountain / Trail Model year: 2025
Sample: 1,384 bicycles with this information
Coverage: 74.6% of the class

Shifting

Electronic

388 of 1,849 bicycles with this information use electronic shifting.

Cohort: Mountain / Trail Model year: 2025
Sample: 1,849 bicycles with this information
Coverage: 99.6% of the class

Gearing

Estimated speeds at 80 rpm

Lowest gear: 6.8 km/h
Highest gear: 35.5 km/h

Total gear range 520%

Technical details and class reference

These speeds describe the gearing at the selected cadence, not how fast you can ride.
Calculated from published gear-inch values and their wheel-size assumptions.
These gearing values describe the bicycle, not a selected frame size.
A 100% range means one ratio; 500% means the highest ratio is five times the lowest.
For e-bikes, motor assistance cutoff is not represented.

Gear-inch range

Lower gear-inch values travel less distance per pedal revolution; higher values travel farther.

This bicycle: 17.9–92.8 gear inches
Class reference (p10–p90): 17.1–98.6 gear inches; The band runs from p10 for the lowest gear to p90 for the highest gear.

Cohort: Mountain / Trail Model year: 2025
Lowest gear: 1384 bicycles with this information, 74.6% of the class
Highest gear: 1384 bicycles with this information, 74.6% of the class

Lineup changes

The published facts that differ across this family's builds and from the same model a year earlier. Missing information never counts as zero.

Differences across 2025 builds

Differences across 2025 builds
Specification	This bicycle YT Industries Jeffsy Core 4 CF 29	YT Industries Jeffsy 29 Core 1 AL	YT Industries Jeffsy 29 Core 2 AL	YT Industries Jeffsy 29 Core 2 CF	YT Industries Jeffsy 29 Core 3 AL	YT Industries Jeffsy 29 Core 3 CF
Frame
Frame material	Carbon	Aluminum	Aluminum	Carbon	Aluminum	Carbon
Bicycle weight	14.6 kg	16.5 kg	15.8 kg	15.1 kg	15.8 kg	15.8 kg
Drivetrain
Front chainrings	1	Not informed	Not informed	Not informed	1	1
Smallest chainring	32	Not informed	Not informed	Not informed	Not informed	Not informed
Largest chainring	32	Not informed	Not informed	Not informed	Not informed	Not informed
Rear sprockets	12	12	Not informed	Not informed	10	10
Smallest sprocket	10	Not informed	Not informed	Not informed	Not informed	Not informed
Largest sprocket	52	Not informed	Not informed	Not informed	Not informed	Not informed
Lowest gear	17.9 in	Not informed	Not informed	Not informed	Not informed	Not informed
Highest gear	92.8 in	Not informed	Not informed	Not informed	Not informed	Not informed
Cockpit
Derailleur hanger	UDH	Not informed	Not informed	Not informed	Not informed	Not informed
Seatpost	Dropper seatpost	Rigid seatpost	Dropper seatpost	Dropper seatpost	Dropper seatpost	Dropper seatpost
Shifting	Electronic	Mechanical	Mechanical	Mechanical	Electronic	Electronic
Other specifications
Bottom bracket standard	BB86/BB92	Not informed	Not informed	Not informed	BSA	Not informed
Wheel material	Carbon	Aluminum	Aluminum	Aluminum	Aluminum	Aluminum