Re: Power in the right places?
I don't know a thing about how the GP1 bikes feel, but the difference between a twin and a four is fairly well recognized. Tires are subject to both static and sliding friction. The former is how much the tire resists sliding before it starts to slide, and the latter is how much resistance is offered once grip has already broken. Static friction is MUCH stronger than sliding friction.
Engines deliver power in distinct pulses when each cylinder fires. When the bike is really making power (and the engine is revving high), those power pulses are delivered very frequently, especially on a four, which has four pulses for every 2 revolutions of the crank (usually). Once the tire starts to slide, it is the much smaller coefficient of sliding friction that is responsible for stopping the slippage. If another power pulse is delivered before the tire regains grip, it is likely that the tire will continue to slide. Since a 4 delivers power to the tire twice as often as the twin (more actually, since the fours make good power at higher revs, so the engine is spinning faster), the 4 is MUCH more likely to cause the back end to slip under power. This means that a well ridden twin can usually be under power quite a bit before an inline four in the same corner at the same speed. That makes a twin a LOT easier to ride. Even the difference between an inline 3 and a twin of the same displacement is quite noticeable (Triumph Daytona vs Mille R, for instance). This is, at least partly, why the V-four in the Ducati GP1 bike will have the same firing order as the twins (2 cylinder at a time, rather than 4 distinct pulses).
The comment about the power of the big G making it far superior to the other open classers was made about racetrack performance. At the racetrack, it isn't about how easy it is to ride a bike, but how fast you get it around the track. That is not the case on the street, where it is all about rideability. At least, it is if you are planning to survive to your next ride. I don't have enough time in the saddle of an open class four to say which is the better bike, but I have tens of thousands of miles on triples and twins, and I know that I prefer the delivery style of the twin over anything I have ridden, including all of the bikes reviewed in the open class shootout. Then again, I am far from the fastest person at the track, and my sense of self preservation usually overrides my right hand on the street, too.
There is no question that the Aprilia would lose the top gear roll on test, but let's see which bike performs better when you snap the throttle open 3/4 of the way through a 2nd or 3rd gear turn. The big G will slide and then high side (or probably just loop you over backwards), and the Aprilia will just drive nicely out of the turn. Basically, the twin is more tolerant of any mistakes AND has the ability to go very fast when ridden well on the street, where excessive power is only a liability. How often do you or I have an opportunity to go to wide open throttle in top gear, anyway. I try to keep my bike OFF the freeway (and out of Nevada) whenever I can.
In the interests of 'journalistic integrity' I should disclose that I bought a Mille on Saturday and absolutely ***** LOVE it, just in case you couldn't tell.
