2018 Specialized Stumpjumper Carbon 29/6Fattie vs 2020 Specialized Stumpjumper ST Alloy 29
The XL is the Specialized Stumpjumper ST Alloy 29 size closest to your XL Specialized Stumpjumper Carbon 29/6Fattie. 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 Specialized Stumpjumper ST Alloy 29
Compared with the Specialized Stumpjumper Carbon 29/6Fattie in XL, the Specialized Stumpjumper ST Alloy 29 in XL places the top of the head tube 8 mm lower and 13 mm further forward, relative to the bottom bracket. Its wheelbase is 20 mm longer, which can contribute to stability at speed.
- Frame stack
- −8 mm
- Lower front end
- Frame reach
- +13 mm
- Longer frame reach
- Wheelbase
- +20 mm
- Longer: steadier at speed
- Head angle
- −0.5°
- Slacker: calmer steering
- Chainstays
- ±0 mm
- About the same
The two frames
Specialized Stumpjumper Carbon 29/6Fattie, XLSpecialized Stumpjumper ST Alloy 29, XLDrawn to scale and lined up at the bottom bracket.
Geometry side by side
| Measurement | Specialized Stumpjumper Carbon 29/6Fattie XL | Specialized Stumpjumper ST Alloy 29 XL | Difference |
|---|---|---|---|
| Reach | 457mm | 470mm | +13 mm |
| Stack | 664mm | 656mm | −8 mm |
| Head tube angle | 67° | 66.5° | −0.5° |
| Seat tube angle | 74° | 73.7° | −0.3° |
| Effective top tube | 648mm | not listed | |
| Chainstay length | 437mm | 437mm | ±0 mm |
| Wheelbase | 1212mm | 1232mm | +20 mm |
| BB drop | 33mm | 33mm | ±0 mm |
| BB height | 338mm | 341mm | +3 mm |
| Standover | 777mm | 776mm | −1 mm |
| Seat tube length | 523mm | 505mm | −18 mm |
| Fork length | 560mm | 560mm | ±0 mm |
| Head tube length | 95mm | 140mm | +45 mm |
Differences are the Specialized Stumpjumper ST Alloy 29 minus the Specialized Stumpjumper Carbon 29/6Fattie. Full charts: 2018 Specialized Stumpjumper Carbon 29/6Fattie, 2020 Specialized Stumpjumper ST Alloy 29.
Where each sits in its class
Specialized Stumpjumper Carbon 29/6FattieSpecialized Stumpjumper ST Alloy 29
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 | Specialized Stumpjumper Carbon 29/6FattieS-Works Carbon 29/6Fattie | Specialized Stumpjumper ST Alloy 29 |
|---|---|---|
| Rear shock | Öhlins STX | not listed |
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