Aprilia debuted its first lightweight twin in the form of the RS 660. Built around a 660cc parallel twin that delivers a claimed 100 horsepower, Aprilia is moving the bar for performance in this engine category. That parallel twin is essentially a re-worked single bank of the V4 found in other Aprilia larger-displacement models. Combined […] The post Beautiful Aprilia RS 660 Takes Lightweight Twin Performance to New Levels appeared first on MotorcycleDaily.com - Motorcycle News, Editorials, Product Reviews and Bike Reviews. Click here for full story...