Aprilia RSV Mille R:

Aprilia's RSV Mille hit American soil last year, and wasted no time winning our Sport-Twins comparison test. Shortly thereafter, the Italian bike-maker unleashed the even racier Mille R, which came standard with race-spec Öhlins suspension, lightweight forged-aluminum wheels and various carbon-fiber bits. Mama mia!

This year, Aprilia made more than 170 detail changes to the Mille and Mille R. I recently rode both bikes at Florida's Homestead-Miami Speedway, and came away impressed with their enhanced performance.

Aprilia's extensive Grand Prix and World Superbike racing efforts directly influenced development of the Mille, specifically its revised chassis geometry. To move weight concentration nearer the bike's center of gravity, the engine is now located 5mm higher in the twin-spar aluminum frame. And to optimize the relationship between chain tension and suspension action for better traction, the swingarm pivot was raised 3mm. Finally, the steering-head angle was relaxed from 24.5 degrees to 25.0 degrees. This, Aprilia says, further fine-tuned weight distribution for improved stability, steering response and feel.

Aesthetic changes run from nose to tail. All-new bodywork is said to have less aerodynamic drag for a 2-mph gain in top speed. Headlight-flanking shrouds allegedly smooth airflow around the rider's arms and shoulders. Air management is further enhanced by a narrower windscreen and array of fairing ducts and slots. A lower, shorter gas tank makes for better ergonomics, and offers a greater feeling of compactness compared to the previous model. The changes to the tank necessitated a lower-profile airbox, too.

Aprilia's RSV Mille R tips the scales at a claimed 403 pounds, 8 less than the standard Mille. It costs more, though, $17,299 versus $13,899. Bhp claim for both is 128.

Few changes were made to the Rotax-built, fuel-injected, 60-degree V-Twin. Although a dry-sump oiling system was already in place, significant effort went into reducing power-sapping oil splash in the lower end. Engineers also pointed out that increasingly stringent noise regulations continue to present a great challenge — hence the harmonics-reducing ribbing on various engine covers.

On the racetrack, the only noise I heard was Mille music, which was particularly stirring when astride the R-model, fitted with a freer-flowing, oval-section accessory muffler. Both bikes have a broad, linear spread of power that made for strong corner exits. The all-new Brembo front brake calipers, meanwhile, scrubbed speed with exceptional ease. Lap times between the two bikes were pretty much identical, so while the $3400-more-costly R offers undeniable exotic appeal, less mercenary Mille lovers can opt for the standard RSV and feel no shame.