In The Paddock
The British GP was a great race, and fascinating at a deeper level as well as the raw excitement of a battle won by inches at the last gasp—fourth-closest margin in the history of racing.
That a (relatively) slow bike like the Suzuki, ridden by a (relatively) inexperienced MotoGP rider like Alex Rins could beat the great maestro Marquez on his all-conquering Honda was almost entirely unexpected.
And yet, to some faceless keyboard commentators waffling on the interweb, in spite of no more engineering or mathematical training than an earwig, it was easily explicable.
Apparently, it is because of the engine architecture. Like this.
The inline Suzuki engine has a longer crankshaft (actually wider, in terms of how it sits in the motorcycle); the V4 Honda’s crank is shorter. This width apparently makes all the difference, even though they probably weigh more or less the same and are spinning at the same sort of speed and in the same direction (backward, opposite to the wheels).
The 20,000-plus rpm reverse spin clearly has some effect in opposing the gyroscopic forces of the wheels, especially in terms of precession. There is also a torque reaction to the spin, which comes with any change of revs. In short, a backward-spinning crankshaft, when accelerating, will tend to rotate the rest of the bike in the opposite direction, adding weight to the front. And vice versa, when decelerating. The beneficial influence is apparent—resisting wheelies under acceleration, doing the reverse under braking.
The next conclusion reached by these pundits is, however, a bit harder to swallow: that the extra width of the Suzuki’s (or also similar in-line Yamaha’s) spinning crank makes enough difference compared with the narrower Honda (or Ducati, KTM or Aprilia) to make all the difference at tracks of a certain character.
Tracks like Silverstone, and Assen, and also Phillip Island, wherein all cases speeds are high but straights not very abundant. Tracks with high-speed corners.
Sounds like over-eager nonsense to me. Yet there has to be some truth, and hopefully a better theory. Because, apart from the exception of CotA where Marquez fell off, these three circuits are the only ones since Vinales’s Yamaha took Le Mans in 2017 a place where either a Honda or a Ducati V4 has not won.
I think it’s more to do with chassis design and engine tune than crankshaft width, and that there is less acceleration from slow corners.
More than any subtle effects of engine architecture, however, it illustrates the scale of Marquez’s talent. The Honda, improved this year with more power and better balance, would seem to be by far the best bike on the grid, but Rins’s Suzuki win suggests otherwise. In fact, the margins are minimal. It is Marquez who makes the RC213V look so good.
He probably could have been a bit more ruthless at Silverston, but since Rins is no title threat and since he, once again, extended his big points lead over Dovi, this lent plausibility to his assertion that “to win the war you must lose some battles.”
So how good (or bad) is the Honda? New teammate Lorenzo’s efforts to tame the unruly V4 have seen him struggling at the far end of the points, and frequently injured by the bike’s savagery. Unlike the rider-friendly Yamaha on which the smooth stylist won three titles, the Honda needs to be wrestled into submission.
Independent-teamster Cal Crutchlow has made the podium twice this year, but his results are unpredictable at best, and he too finds the Honda easy to crash. After his major ankle injury last year in Australia, the Briton was talking at Silverstone about possible retirement, saying evocatively, “I’d like to be able to walk in a straight line again.”
In this contest of small margins, it is definitely Marquez who flatters the Honda. And he’s had to change his approach and tactics to do so.
“In the past, I preferred to wait until the end of the race to push.” He could afford to save his tires, knowing that he could be relatively relaxed in the early laps without losing too much ground.
“This year,” he says, “everyone can be fast on new tires. I need to push from the start to try to make an advantage, and then control the race from there.”
It doesn’t always work for the win. In Austria, the more powerful Ducati was able to follow and use its advantage at race-end; at Silverstone, the sweeter-handling Suzuki had saved more tire for that crucial last-corner pounce.
But in both cases, Marquez showed how his tactics contribute to a steadily growing tally of points because in each case it was just the two of them left in it. The worst that could happen to Marquez was second place.CN