Harley-Davidson Fat Boy S vs BMW R 18 B (2025)
Side-by-side spec comparison, pricing, and a plain-English breakdown of how the Harley-Davidson Fat Boy Sstacks up against the BMW R 18 B. Numbers pulled from manufacturer spec sheets — click either bike for the full review.
Spec comparison
| Spec | Harley-Davidson Fat Boy S | BMW R 18 B |
|---|---|---|
| Model year | 2016 | 2025 |
| Price | $19,699 | $20,375 |
| Engine | 1801 cc | 1802 cc |
| Horsepower | 93 hp | — |
| Torque | 146 Nm | 163 Nm |
| Weight | 320 kg | 398 kg |
| Seat height | 26 mm | 719 mm |
| Fuel capacity | 5.0 L | 23.8 L |
| Fuel type | petrol | petrol |
| Transmission | 6-speed | Manual |
| Front brakes | Double disc. ABS. 4-piston. | Dual Hydraulic Disc |
| Rear brakes | Single disc. ABS. 4-piston. | Hydraulic Disc |
| Tires | 140/75-R17 / 200/55-R17 | 120/70 R19 / 180/55 B18 |
Harley-Davidson Fat Boy S vs BMW R 18 B — which should you buy?
Picking between the Harley-Davidson Fat Boy S and the BMW R 18 B usually comes down to the numbers you care about most. On paper, the Harley-Davidson Fat Boy S brings 93 hp in a 320 kg package, while the BMW R 18 B counters with its own power figure at 398 kg. On price, the Harley-Davidson Fat Boy S has the lower MSRP.
Our spec tables above highlight the winning number on each line. For the full rider-focused reviews including real-world fuel economy, service costs and available colors, click into either bike: