Ryder Notes: The Truth About Traction Control
by julian ryder, back home in the uk now
Tuesday, May 13, 2008
To listen to some people, you would think that the rider no longer has to do anything to go fast on a MotoGP bike. According to the prophets of doom, MotoGP has already gone the way of Formula 1 and anyone could climb on an 800 and crack the throttle open without fear of the consequences.
The culprit is, of course, traction control, otherwise known as Spawn of Satan.
So how come Jorge Lorenzo managed to replicate the classic 500cc-era highside crash on the first day of the Chinese GP? It was a slow-speed crash but Jorge was flicked a long way up in the air, at one point he was doing a handstand six feet above the tarmac. It let go as he picked the bike up from the long, long righthanded first corner and pitched it into the only slightly shorter left that is the second turn, the rear tyre skidding out to the right as it was asked to provide some grip on the left side. It was in fact a classic cold tyre crash.
In search of what traction control can and cannot do I went to Jerry Burgess, race engineer for Valentino Rossi and a man with the rare ability to reduce a complex situation to the few facts that actually matter. On the subject of Lorenzo's crash he pointed out that traction control only works along the axis of the bike, not at 90 degrees to the direction of travel: "Traction control won't stop you crashing." Jerry does allow, however, that TC has "definitely made life easier" for the rider. However, "if the rider is aggressive it will still spin, you can ride through it." Here is one of the important truths of electronic controls, they work within their well-defined parameters but not outside them. Jerry Burgess illustrates this by pointing to the example of wheelie control: "Every bike out there has it, so how come they can all wheelie after the flag?" So what about the urban myth of a rider getting to the apex, cracking the throttle wide open and letting the electronics sort everything out? That, says Burgess, could only happen if the electronics are set to totally reject any inputs outside of its parameters. In other words, if the computer decides you are having a laugh, it says no. Yes, you could set things up to let you take total liberties with the throttle but it would result in a very slow lap time as the electronics refused to allow any power to be transmitted to the rear tyre.
The reality, says Burgess, is that no matter how good a TC system is the rider must still have a feeling for what the bike will do.' He likens it to riding a horse; you can't expect it to do what you want if you just yank on its mouth with the reins, you need that elusive understanding of the way the animal behaves to get the best results.
But what about that other piece of evidence the miserablists always trot out, the impressive showings of the rookies in MotoGP this year? For starters, JB is of the opinion that referring to riders like Dovizioso and especially Lorenzo as rookies is verging on the insulting. They come from the 250s, a class that requires high corner speeds and lean angles, just as the 800cc MotoGP bikes do. That and the undisputed fact that electronics have made life easier to some extent are, says JB, "good for clearing out the deadwood." By which he means riders who he regards as past their sell-by date. This is one reason Jeremy hates the idea of replacing the 250s with what he refers to as "some sort of antiquated hybrid," - actually he uses much stronger vocabulary, but you get the idea.
Dragged back onto the subject of electronics, JB defines traction control as another set-up tool, albeit a powerful one. Back in 2002 when the Repsol team tested Honda's first traction control system at Valencia, JB recalls Rossi getting off the bike and saying "Don't tell anyone, but this isn't fair!" And that was a simple system that compared front and rear wheel speeds and retarded the ignition timing if they were different by more than a set percentage. Nowadays, TC systems are almost infinitely variable with maps that alter the electronics' intervention with respect to lean angle and corner speed differently for every gear.
Nevertheless, JB doesn't even like using the phrase 'traction control'; he prefers all the electronics to be called 'aids' not 'controls'. His final word on the subject sums up his argument: "If it's only about traction control then any tyre should be OK."
ENDS
...egy fecske nem csinál nyarat, viszont egy hülye százat csinál...
Másodikra 9 ezreddel sikerült neki 
