The compact, 65-degree V4 engine is mildly modified for reduced internal friction. A revised fuel-injection system, new silencer and other minor changes increase the maximum output by 3bhp to 170bhp. (It’s the Tuono, so not all the updates are strictly sensible…)  The 16-valve V4 is a wonderful engine: powerful, flexible and bursting with character, all enhanced by a soulful exhaust note. It makes the Aprilia addictively quick and fun, especially when the bike is revving hard through its six-speed gearbox, its fierce acceleration aided by the electronic quick-shifter that is standard fitment.  Like the RSV4, the Tuono benefits from Aprilia’s sophisticated APRC electronics package, which incorporates a traction control system that can be regulated while riding, via buttons on the left handlebar. This works brilliantly, adding a useful safety net, and is further refined for this bike with a new sensor that optimises performance to suit cornering speed.  Part of the appeal of naked sports bikes is that their upright, relatively exposed riding position enhances the sense of speed. That’s true of the Tuono, although its half-fairing gives some wind protection, as well as adding stability. It’s a compromise that comes in useful long before the bike reaches its top speed of more than 160mph.  Aprilia has also tried to improve comfort and practicality. The engine’s Achilles’ heel is its thirst, which can drop below 30mpg with hard use. That hasn’t changed but the tank is enlarged to give a usable range of 125 miles or more. The more generously padded seat makes covering that distance a less painful prospect, though the footrests are set high and a pillion doesn’t have much to hold.  The multi-adjustable suspension’s standard settings are softened slightly to improve comfort, without detracting from the superb handling that is another of the Tuono’s greatest assets. The wide, raised handlebar’s leverage helps make the commendably light Aprilia gloriously agile, yet it’s stable at speed.  The uprated braking system is fiercely powerful although on the track I was disappointed to find the ABS system cutting in surprisingly frequently, admittedly on a tricky, partially damp surface.  Even this slightly softened Tuono should not be mistaken for a luxurious long-distance machine. In super-naked tradition it’s effectively a high-barred sports bike, designed primarily for performance and entertainment. The important difference from the old model is that it is now also respectably, if not outstandingly, practical.  Inevitably the Tuono is far from cheap, but its price of £12,432 is not excessive given its performance and electronic sophistication – and, more to the point, its sheer fun factor. Competition in motorcycling’s super-naked division is hotter than ever, but Aprilia’s updated original is arguably still the one to beat.  Tested: 999cc V4 four-stroke, six-speed transmission  Power/torque: 170bhp @ 11,500rpm/82lb ft @ 9,500rpm  Range: 125 miles @ 35mpg (estimated)  Verdict: Addictively entertaining, usefully updated high-barred V4 sports bike whose outstanding levels of performance and technology are now matched by reasonable practicality  Telegraph rating: Five stars out of five  This higher spec version of the stripped-down S1000RR combines its 160bhp performance, agility and keen price with an array of features including semi-active suspension and heated grips.  Kawasaki Z1000 Special Edition ABS, £10,099  Revamped for 2014, Japan's leading super-naked complements its aggressive style with 140bhp output and taut handling but can't match the Tuono's performance or electronic refinement.  KTM 1290 Super Duke R, £13,999  The bike they call the "Beast" packs a 180bhp V-twin punch with thrilling midrange power delivery, fine handling, all-round ability and a refined electronics package, but its price is high.
The Aprilia Tuono V4R is one of the fastest and most accomplished naked bikes   on sale