If you've been jonesing for a pint-sized performance motorcycle that corners on rails, this could be just the fix you need.If you buy from a link, we may earn a commission. Learn moreGiven most riders' preferences for power and presence here in Freedomland, many awesome small-displacement motorcycles never hit the US market.This proves especially true in the case of street bikes because of emissions and noise regulations. Many of the pint-sized performers you get overseas rely on smoky two-strokes that don't fly. AdvertisementAdvertisementOf course, occasionally, some do manage to slip through the cracks. Just take this pristine pocket rocket that recently surfaced over on Bring a Trailer as an example. Aprilia officially brought the RS125 to the United States in 2009 as a closed-course-only model. - Credit: Bring a Trailer (911r)Aprilia's stateside track specialIt's a 2009 Aprilia RS125, and the Italian 125cc is a small bike standout for a few reasons. For starters, it wears an exclusive livery celebrating Julian Simon's 2009 250cc title. Aprilia designed the RS125 as the littler sibling to the platform, so it's a bit of a full circle moment.Don't let the small-displacement single make you think this Aprilia is any less performance-focused. - Credit: Bring a Trailer (911r)Even more notable than the motorsport-inspired looks, though, is that 2009 was the only year Aprilia officially brought this boy racer to the United States. Mind you, the RS125 had already enjoyed a lengthy production run by that point, debuting all the way back in 1992.AdvertisementAdvertisementThe visa did come with a considerable caveat. Despite the bike's road-going status in Europe, it wasn't homologated for the street. Even with equipment like lights, mirrors and turn signals, Aprilia could only get it approved for closed-course use here because of the powertrain.Those sliders protect the bodywork should you get a little over-ambitious in the turns. - Credit: Bring a Trailer (911r)Still, much as you might think that reduces the RS125's appeal, a track is exactly the kind of environment that allows the bike to be enjoyed to its fullest.A lightweight corner killerAfter all, though this tiny sport bike packs as many cubes as a moped, it punches up in more ways than one.Being propelled by a two-stroke Rotax single, it makes its power high in the rev range, so you need to be winding it out near redline to be getting all of those (checks notes) 32.5 horses. The angular styling is meant to ape Aprilia's larger performance motorcycles. - Credit: Bring a Trailer (911r)Though that doesn't sound like much on paper, it's worth pointing out that this Aprilia was light as a feather. Thanks to its bare-bones provisions, the RS125 tipped the scales at 280 pounds dry.AdvertisementAdvertisementIn combination with its aluminum twin-spar frame and box-section dual-sided swingarm, this made it a true corner killer. As Motorcyclist put it in its review, "What you do expect is handling, and here the RS 125 truly shines. Riders comment on its responsiveness and the speed with which it corners and how much fun it is to ride as you lean into turns."How about that swingarm? - Credit: Bring a Trailer (911r)I'd say that amounts to as glowing an endorsement as any, though it's the line that follows that warrants extra appreciation: "Although it is a small machine, taller riders don't feel cramped while riding."Yours to ownAs such, the RS125 isn't just for beginners and younger racers. Whether you're hitting the track for the first time or looking for something smaller to hone your lines, it helps to be astride something a little lighter and tamer at the throttle. If you're taken by the featured Aprilia, you can learn more through the listing, where there are still six days left in the auction as of this writing. With just 12 miles shown on the odometer, it makes for a bike that's a small-displacement unicorn on account of more than its exceptional stateside presence.2009 Aprilia RS125 Learn More AdvertisementAdvertisementAbout the Author: Gray is an associate editor at Gear Patrol, covering cars, motorcycles and anything else with wheels. When he's not chasing the latest industry news, he's probably wrenching on one of many projects. For better or worse, he believes classics make perfectly practical daily drivers.Want to stay up to date on the latest product news and releases? Add Gear Patrol as a preferred source to ensure our independent journalism makes it to the top of your Google search results.