BMW R 1100 S 2004 — Specifications

Can you really make a sportbike with a flat-twin? BMW answered that question back in 1998 with the R 1100 S, and the answer can be summed up in one word: differently. Produced until 2005, this BMW R 1100 S never tried to play the same game as Japanese four-cylinders. Where a Honda VFR 800 banks on sensible versatility and where Suzuki GSX-Rs or Honda CBRs rev like Swiss watches, the German machine offers a vision of sport riding infused with mechanical nobility. Its 1085 cc boxer, with two large horizontally opposed cylinders, 4 valves per cylinder and an 11.3:1 compression ratio, produces 98 hp at 7250 rpm and, more importantly, 97 Nm of torque from just 5750 rpm. This is not an engine that screams at high revs. It's an engine that pushes, hard, between 3000 and 5000 rpm, with a generosity that is typically boxer. Beyond that, the thrust tapers off, but a top speed of 227 km/h proves the numbers add up.

The three-piece composite chassis, with the engine as a stressed member, relies on the famous Telelever at the front and the Paralever at the rear, a cast aluminum single-sided swingarm that showcases the rear wheel fitted with a 180/55 ZR17 tire. The BMW R 1100 S spec sheet reveals a 1478 mm wheelbase and a wet weight of 229 kg. On paper, that's heavy for a sportbike. In practice, the boxer's mass distribution and the frame's rigidity deliver remarkable stability. The rear suspension, adjustable in hydraulic preload via a knob accessible even while riding, lets you adapt the handling in seconds. On rough roads, this ease of adjustment is a game-changer. Braking duties fall to Brembo calipers, twin discs up front with four-piston calipers, delivering precise stopping power. The aerodynamic protection lives up to its promises up to 180 km/h, which says a lot about this machine's true calling.

And that's really the point. The BMW R 1100 S Boxer Cup made its name in a single-make racing series reserved for gentleman riders, but in daily use, this bike leans decidedly toward the sport-GT side. An 18-liter tank, an 860 mm seat height, fuel consumption of 6 liters per 100 km, shaft drive and a six-speed gearbox: everything is designed to devour miles without compromise. The shaft drive, in particular, frees you from chain maintenance and provides a level of riding convenience that Japanese sportbikes of the era simply didn't offer. Flaws? They exist. Agility through tight sequences of corners is not the machine's strong suit, its 229 kg making themselves felt in slow turns. And the twin's vibrations remain a persistent travel companion, especially on the highway. That's the price you pay for such a distinctive character.

On the used market, the BMW R 1100 S remains a safe bet for anyone seeking an atypical motorcycle. Model years 1999 to 2004 can be found at reasonable prices, and the boxer's reliability is well established. Dedicated forums are full of owner feedback on recurring issues, mainly electrical and age-related, nothing that should be a deal-breaker. Some owners have turned their R 1100 S into a cafe racer, taking advantage of the boxer's low profile to create radical-looking machines. Others, fans of Randy Mamola and his stint in the Boxer Cup, keep theirs in original condition. At 12,600 euros new in 2004, it carried an unapologetic premium price tag. Today, it's precisely this unconventional positioning that makes it so appealing. Neither a true sportbike nor a true GT, the BMW R 1100 S carves its own path with a poise that only a flat-twin can deliver.