YT Industries Jeffsy 29 Core 4 CF

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

2025 MountainTrail Manufacturer page

Last known price: $6,299

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

Rider height by size (cm)

Size guide

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

Brakes

1 part

Brakes
- Hayes

Wheels and tires

2 parts

Cockpit and contact points

6 parts

Sizes and geometry

10 sizes Open in the geometry plotter

Enter your height to highlight matching ranges.

Size LG Low

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 10 published sizes

Complete manufacturer geometry by size
Measurement
Reachmm	442	435	462	455	481	475	495	501	515	521
Stackmm	608	613	615	620	622	627	634	629	642	636
Top tube lengthmm	562	578	585	593	607	609	627	630	645	652
Seat tube lengthmm	385	385	410	410	435	435	460	460	485	485
Head tube lengthmm	100	100	108	108	116	116	124	124	132	132
Head tube angle	65.6°	65°	65.6°	65°	65.6°	65°	65°	65.6°	65°	65.6°
Seat tube angle	77.5°	76.9°	78.1°	77.5°	78.5°	77.9°	78.3°	78.9°	78.6°	79.2°
Chainstay lengthmm	435	437	435	437	435	437	442	440	442	440
Wheelbasemm	1189	1191	1213	1214	1236	1238	1266	1265	1289	1288
Front centermm	755	756	779	779	802	803	826	826	849	849
Bottom bracket dropmm	25	33	25	33	25	33	33	25	33	25
Bottom bracket heightmm	351	343	351	343	351	343	343	351	343	351
Standover heightmm	738	730	736	728	740	732	738	746	742	750
Fork rakemm	44	45	45	45	45	46	45	46	45	46
Trailmm	122	125	120	125	120	124	125	119	125	119
Stack/reach ratio	1.38	1.41	1.33	1.36	1.29	1.32	1.28	1.26	1.25	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
Rear sprockets: 12

Wheels and brakes

Wheel configuration: Same size
Brake type: Hydraulic disc

Fit and controls

Derailleur hanger: UDH
Seatpost: Dropper seatpost
Shifting: Electronic

Additional specifications

Fork spring: Air
Wheel material: Carbon
Wheel size: 29″

Technical analysis

2 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

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

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 29 Core 4 CF	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
Rear sprockets	12	12	Not informed	Not informed	10	10
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
Wheel material	Carbon	Aluminum	Aluminum	Aluminum	Aluminum	Aluminum
Bottom bracket standard	Not informed	Not informed	Not informed	Not informed	BSA	Not informed