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XTERRA Fitness AIR650 vs Sunny Health & Fitness SF-B2618 Air Bike
Quick verdict
Winner on Gym Score: Sunny Health & Fitness SF-B2618 Air Bike (87)
Two budget air bikes that target the same buyer differently. The XTERRA AIR650 has a larger fan (26 inches), heavier flywheel, and feels closer to commercial air bikes. The Sunny SF-B2618 is lighter, smaller, and roughly 30 percent cheaper. For serious HIIT and CrossFit-style workouts, AIR650. For casual cardio and beginners, the Sunny gets the job done at lower cost.
Choose the XTERRA AIR650 if you do real interval work (Tabata, EMOM, Assault-bike-style finishers) and want a bike that handles all-out sprints without flex or wobble.
Read the full review →Choose the Sunny SF-B2618 if you mostly do steady-state cardio, weigh under 220 lb, and don't need commercial-grade construction for short HIIT sessions.
Read the full review →
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Spec-by-spec
| Spec | XTERRA Fitness AIR650 | Sunny Health & Fitness SF-B2618 Air Bike |
|---|---|---|
| Drive Type | Belt | — |
| Fan Material | Steel | — |
| Max User Weight | 350 lb | — |
| Console | Backlit LCD | — |
| Connectivity | Bluetooth | — |
| Resistance | — | Air + magnetic hybrid |
| Drive | — | Belt |
| Display | — | LCD |
XTERRA Fitness AIR650
- +Steel fan
- +Sealed bearings
- +Backlit LCD
- +Heart-rate grips
- −Brand recognition lower than Schwinn
- −Belt-drive servicing harder to find
- −Padding firmer than some prefer
Sunny Health & Fitness SF-B2618 Air Bike
- +Dual-action moving handles
- +Belt drive runs quiet
- +Magnetic + air hybrid
- −Less stout than Echo/Assault
- −Basic LCD display only
- −No app integration
The real tradeoff
Assembly difficulty is similar (60 to 90 minutes), but the XTERRA's heavier components require two strong people for the final lift. The Sunny is a one-person assembly. Long-term, the AIR650's chain drive and steel frame outlast the Sunny's belt drive — expect 5 to 10 years on the XTERRA versus 3 to 5 on the Sunny under regular use.
Skip both if you want the gold-standard air bike experience. The Assault AirBike Classic costs more but is the bike CrossFit gyms use for a reason. Browse /category/air-bikes.
Buyer questions
How big a difference does fan size make?
Meaningful for high-effort intervals. A larger fan (26 inches on the XTERRA, around 22 inches on the Sunny) produces more resistance at high RPM, which is exactly when sprints get hard. For 60-second all-out efforts, the XTERRA feels noticeably more demanding.
Is the Sunny okay for tall riders?
The Sunny accommodates riders up to about 6 feet 2 inches comfortably. Beyond that, the seat post extension and handlebar reach become limiting. The XTERRA fits up to about 6 feet 5 inches with its longer adjustment range. Measure your space and your body dimensions before buying — published specs are accurate but real-world clearances often surprise people.
Which is quieter?
Air bikes are inherently noisy under load — both will hit 75 to 85 dB during sprints. At steady state, the Sunny is marginally quieter due to its belt drive. The XTERRA's chain drive adds a faint clicking sound that disappears under heavy fan noise.