Yamaha has finally released full specifications for its new middleweight street sportsbikes, the naked FZ8-N and semi-faired Fazer8. A 779cc engine derived from the FZ1 donk is the star of the show, with a complete FZ1 frame and swingarm as well. The new engine makes significantly more torque than the smaller FZ6 for a gruntier, more accessible power curve around town - but builds to a healthy 105-horsepower top end rush when it's time to get a boogie on. It looks like a fun, fast and friendly street sportsbike - and yes, FZ6 fans, it has formally replaced the 600 in the FZ lineup.

As many have suspected, the engine is indeed a scaled-down version of the fuel-injected 1000cc FZ1 engine, dropped to 779cc by reducing the piston bore, increasing compression, swapping out the pistons, crankshaft and top end. The resulting motor puts out a touch under 105 horsepower, with 82 Nm of torque.

Yamaha's new FZ8

Effectively, that top-end horsepower figure doesn't seem to be much up on the 90-odd rear wheel horses offered by the lighter, 600cc FZ6 donk. But the stroked-out FZ8 makes its power much earlier in the rev range, a fact which should make it a much more willing and eager powerplant around town and in the majority of real-world riding conditions.

The bad news is that by reducing the FZ1 engine's bore, the FZ8 doesn't manage to shed any engine size or weight. The good news that comes as a corollary is that the FZ8 is blessed with the wonderful FZ1 frame and swingarm, which do an excellent job of providing rigidity and flex in all the right places.

Yamaha's new Fazer8

There's not a lot for gearheads to get excited about elsewhere; suspension seems fairly basic, adjustable only for rear preload, and the brakes are four-piston monoblock jobs, with the option of adding ABS.

There's two versions available, just like with the FZ6 and FZ1 platforms - the naked FZ8-N looks nice and chunky and stylish, and the semifaired Fazer8 looks a little more... Practical. The FZ8-N weighs 211kg ready to roll with a full tank of gas, the Fazer8 215kg - and you can add 5kg to either if you want the optional ABS.

Yamaha's new FZ8

Where does the new Fazer fit?

The FZ8 has clearly been developed to help Yamaha get a foothold in the 750cc class, which is currently occupied only by Kawasaki's Z750 (itself a sleeved-down Z1000) and Aprilia's Shiver. Other key contenders would have to include Ducati's 696 Monster and the excellent Triumph Street Triple 675. You have to wonder why Suzuki doesn't make a sporty naked using its excellent GSX-R750 donk - the only purebred 750cc sportsbike engine on the market - but then, they don't use the Gixxer 1000 engine in a naked, either.

Looking at the engine and weight specs, you'd have to rate it next to Honda's everyman CB900 Hornet as well - I've got a soft spot for those, as I put 60,000km on one a few years back.

100-odd horses and 82Nm of torque should stand the FZ8 in good stead as a powerful but friendly and useable roadbike, and it certainly carries forward Yamaha's tradition of making some the best looking of all the Japanese bikes. So in all, it's no major leap forward, but it's certainly a great addition to the FZ range.

Yamaha's new Fazer8

Speculation has been mounting in certain corners of the Internet that the FZ8 has been designed to effectively replace the FZ6. Such scuttlebutt postulates that the 'friendly' 600cc category will be handled by the more utilitarian XJ6 and Diversion, and that the highly-strung FZ6, which needs a lot of revs to feel like it's taking off, will disappear so that Yamaha can position the FZ range as a naked sports option for more experienced riders. And if Yamaha Europe's website is anything to go by, it seems the rumours are true - the FZ6 and Fazer6 have disappeared altogether.

The FZ6 certainly has its fans, plenty of people like the retuned R6 engine's marked power curve - but if the FZ8 manages to pull off that same top-end rush, while adding in some genuine usable torque down low, I think it's fair to say you've got an all-round more useable bike. We look forward to riding one! Full specs follow, and there's loads of photos in the FZ8 photo gallery.

2011 FZ8-N and Fazer8 Technical Specifications

ENGINE

Type: Liquid cooled 4-stroke,DOHC, Forward-inclined parallel 4-cylinder

Displacement: 779cc

Bore x stroke: 68.0×53.6mm

Compression ratio: 12.0: 1

Max. Power: 78.1KW(106.2PS)/10000r/min

Max. Torque: 82.0Nm(8.4kgf･m)/8000r/min

Lubrication system: Wet sump

Fuel supply system: Fuel Injection

Clutch type: Wet,multiple-disc coil spring

Ignition system: Transistorized coil ignition

Starter system: Electric

Transmission system: Constant mesh 6-speed

Final transmission system: Chain

Primary reduction ratio: 1.512(65/43)

Secondary reduction ratio: 2.875(46/16)

Gear ratio 1st gear: 2.692(35/13)

Gear ratio 2nd gear: 2.063(33/16)

Gear ratio 3rd gear: 1.762(37/21)

Gear ratio 4th gear: 1.522(35/23)

Gear ratio 5th gear: 1.350(27/20)

Gear ratio 6th gear: 1.208(29/24)

CHASSIS

Frame: Deltabox frame

Front suspension: Telescopic fork

Front wheel travel: 130mm

Rear suspension: Swingarm (link suspension)

Rear wheel travel: 130 mm

Caster angle: 25º

Trail: 109mm

Front brake: Hydraulic dual disc brake, Ø 310 mm

Rear brake: Hydraulic single disc brake, Ø 267 mm

Front tyre: 120/70 ZR17 M/C(58W)

Rear tyre: 180/55 ZR17 M/C(73W)

DIMENSIONS

Overall length: 2,140mm

Overall width: 770mm

Overall height: FZ8-N 1,065mm / Fazer8 1,225mm

Seat height: 815mm

Wheelbase: 1,460mm

Min. ground clearance: 140mm

Wet weight (full fuel tank): FZ8-N: 211kg / ABS 216kg - Fazer8: 215kg / ABS 220kg

Fuel capacity: 17 litres

Oil capacity: 3.8 litres