2027 Trek Fuel EX 9.9 Gen 7 vs 2025 YT Jeffsy CORE
The S is the YT Jeffsy CORE size closest to your S Trek Fuel EX 9.9 Gen 7. We match frame stack and reach. This is a geometry comparison, not a fit recommendation; stem, spacers, handlebars and saddle setup also affect your riding position.
What changes on the YT Jeffsy CORE
Compared with the Trek Fuel EX 9.9 Gen 7 in S, the YT Jeffsy CORE in S places the top of the head tube 3 mm higher and 4 mm further forward, relative to the bottom bracket. Its wheelbase is 4 mm longer, which can contribute to stability at speed.
- Frame stack
- +3 mm
- Higher front end
- Frame reach
- +4 mm
- Longer frame reach
- Wheelbase
- +4 mm
- Longer: steadier at speed
- Head angle
- +0.4°
- Steeper: sharper steering
- Chainstays
- ±0 mm
- About the same
The two frames
Trek Fuel EX 9.9 Gen 7, SYT Jeffsy CORE, SDrawn to scale and lined up at the bottom bracket.
Geometry side by side
| Measurement | Trek Fuel EX 9.9 Gen 7 S | YT Jeffsy CORE S | Difference |
|---|---|---|---|
| Reach | 431 | 435 | +4 mm |
| Stack | 610 | 613 | +3 mm |
| Head tube angle | 64.6° | 65 | +0.4° |
| Seat tube angle | 78.7° | 77.2 | −1.5° |
| Effective top tube | 548 | not listed | |
| Chainstay length | 437 | 437 | ±0 mm |
| Wheelbase | 1187 | 1191 | +4 mm |
| BB drop | 34 | 33 | −1 mm |
| BB height | 340 | not listed | |
| Standover | 741 | not listed | |
| Seat tube length | 370 | not listed | |
| Head tube length | 95 | not listed |
Differences are the YT Jeffsy CORE minus the Trek Fuel EX 9.9 Gen 7. Full charts: 2027 Trek Fuel EX 9.9 Gen 7, 2025 YT Jeffsy CORE.
Where each sits in its class
Trek Fuel EX 9.9 Gen 7YT Jeffsy CORE
Each bike is ranked against the other trail bikes on Quiver, on frame geometry alone. Not your hand position or ride feel.
What each ships with
The stock build of each bike's first listed trim. Parts that match are dimmed.
| Part | Trek Fuel EX 9.9 Gen 79.9 X0 AXS Gen 7 | YT Jeffsy CORECORE 1 |
|---|---|---|
| Frame | Trek Fuel EX | not listed |
| Fork | RockShox Lyrik Ultimate | Marzocchi Bomber Z1 |
| Rear shock | RockShox Super Deluxe Ultimate | Marzocchi Bomber Air |
| Shifter | SRAM X0 Eagle | Shimano Deore |
| Derailleur | SRAM X0 Eagle AXS | Shimano Deore |
| Cassette | SRAM X0 Eagle Transmission | Shimano Deore M6100 |
| Chain | SRAM X0 Eagle | not listed |
| Crankset | SRAM X0 Eagle | Shimano Deore M512 |
| Chainring | SRAM X0 Eagle | not listed |
| Bottom bracket | SRAM DUB MTB Large | Shimano MT501 |
| Battery | SRAM AXS | not listed |
| Wheelset | Bontrager Line Pro 30 | Sun Ringlé SR329 Trail Comp |
| Tire | Maxxis Minion DHF, Maxxis Minion DHR II | Maxxis Minion DHF, Maxxis Minion DHR II DD |
| Brake | SRAM Maven Silver | SRAM DB8 Stealth |
| Rotor | SRAM HS2 | not listed |
| Handlebar | Race Face ERA | YT Handlebar 35 |
| Stem | Race Face Turbine R | YT Stem 35 |
| Grips | Trek Line Elite | ODI Elite Motion V2.1 |
| Dropper post | RockShox Reverb AXS | not listed |
| Seatpost | RockShox Reverb AXS | YT Seatpost |
| Saddle | Trek Aeolus Pro | YT Custom Design |
| Headset | not listed | Cane Creek Series 10 |
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