Tuesday, December 18

MV AGUSTA 675 IS A STUNNER

By MICHAEL ESDAILE 

IT WAS revealed two years ago at the Milan Show but it took a while to go into production and even longer before the first models arrived in New Zealand. Then it was some months before the importer took a couple out of the second shipment and turned them into demonstrator bikes for the press and seriously interested buyers to sample.

At Milan in November 2010, Italian monthly Motociclismo conducted a survey of show goers and when all the votes were tallied, the new three cylinder 675cc F3 MV Agusta was voted 'the most beautiful bike in the show'. The MV captured 38.5% of the votes cast, well ahead of the Ducati Diavel which received 20.6%.





There is no denying the beauty of this new MV. Just like the first modern MV Agusta - the 750cc four cylinder F4 - the F3 is a delight to look at. Unlike the F4 though, it is also a delight to ride. Actually, let me re-phrase that. The F4 was a delight to ride out on the open road, but around town, the riding position was literally a pain in the neck.

However, you sit further forward on the F3, the handlebars do not seem to be as low, so 'transport' sections are not the problem they were on the F4.

In the engine department, the new 675cc triple runs rings around the old 750cc F4. This thing has some serious get up and go. And with radial-mount brake calipers, it stops as well.

Enduro and cross-country ace Chris Birch was paying one of his regular visits to KR HQ last week, spotted the F3 and was in raptures about how good it looked. We told him to take it for a fat. He demurred, claiming he wouldn't know how to ride a road bike. We told him that if he could win the Roof of Africa, place on the podium of the Erzberg Enduro and generally be comfortable skidding around at up to 160 km/h on the dirt, riding the MV would be a cinch.

So he hopped aboard and disappeared up the road, the three cylinder engine playing its lovely melody as he ran it up the revs in second gear. He was away for a short while, then came back with a silly grin on his face. He reported that the front wheel came up easily in power-on mode and "it does great stoppies."

At this point his wife scolded him for enjoying himself too much and marched him off to do some Christmas shopping.

It is no exaggeration to say that the 675 MV engine is right at the cutting edge of current technology. It is a big-bore, short stroke engine (the bore-to-stroke ratio is 1.72) that pulls well from low rpm and positively screams away in the mid-range. Due to the presence of those party poopers with radar guns, I did not sample the upper registers of the rpm scale, but the way my bum was pushed back in the seat when it started getting into its stride, it will be quite intoxicating on the race track.

You may have read a bunch of journos writing that the F3 has a counter-rotating crankshaft, something it is said 'calms' the front-end of the bike if the throttle is rolled off mid corner. That's something only a track test will highlight. However, what struck me in all I have read about this engine was that none of the English language writers had explained how MV achieved this in such a compact engine.

Sitting looking at the left-hand side of the engine, it was obvious the drive to the dual overhead camshafts came from a drive sprocket behind and a little to the left of the left cylinder. I knew that the engine used a balance shaft to help quell the vibration induced by the rocking-couple of an in-line three cylinder engine.

"Could it be," I mused to KR tester and former national Formula III champ Rodney O'Connor, "that MV is using the balance shaft to drive the cams, and is also using it as the intermediate shaft to drive the clutch?"

Like most, Rodney did not know as detailed tech information is often hard to come by from either manufacturers or their local distributors these days.

Don't ask me why, in this so-called 'switched-on' age, that some sections of the motorcycle industry are so backwards.

However, I figured that if anyone would know the details of the MV Agusta F3 engine layout it would be Italian journalist and writer Bruno de Prato. So I emailed Bruno.

Back came his response: "you are exactly right, the balancing shaft doubles as an intermediate primary transmission shaft and consequently the crankshaft counter-rotates, with positive consequences on the handling of the bike. I also found that the MV Agusta F3 675 is a little monster with excellent everything and I look forward to testing the Brutale 800, with the stroked three making about the same power as the F3, but with gobs of extra torque. I have taken the whole engine apart and analyzed it very accurately and I must say that indeed it is a very clever project down to the last detail and I am sure that it will make one hell of a show in the World Supersport Championship."

It turns out that Bruno had supplied a stack of detail shots of the engine to American Cycle World magazine. They can be viewed on its website. Click here: http://www.cycleworld.com/2012/04/01/view-from-the-assembly-line-2012-mv-agusta-f3-675-feature to find them.

Enjoy!