The Big Picture
in [Racing]
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From: Bruce Richmond on 18 Sep 2009 23:06 On Sep 18, 10:17 am, Mark N <menusbaumNYETS...(a)earthlink.net> wrote: > Bruce Richmond wrote: > > Dirt wrote: > >> There's valid reason behind the notion that nothing more than a > >> reduction in engine size will enable a bike to go around corners > >> faster. I don't understand it fully, so I'll keep it simple as much > >> for my own explanation as anything, but... > > > I don't think it is engine size so much as power, or power to weight. > > The rider experiments to find out what works best and finds that for a > > lower powered bike it is best not to slow down any more than you have > > to. > > > The higher the cornering speed the greater the commitment of the rider > > to accept risk of falling in the turn. On the more powerful bike the > > rider has the option of slowing a bit more, cornering at reduced risk, > > and still getting back up to speed. The lower speeds can also > > translate into sharper but shorter turning. That allows it to spend > > more time upright where it can play its trump card of acceleration. > > It could quite likely corner as fast as the less powerful bike, or > > very close to it, but doing so would limit its acceleration leaving > > the turns. The more traction you are using for lateral forces the > > less you have left for acceleration. If the less powerful bike slows > > down to the same speed as the more powerful one it gets left behind in > > the drag race out of the turn. > > The problem with this, I think, is that it would take experimentation to > arrive at an approach which would result in maintaining the old lap > times, and there probably would be a certain amount of crashing in that > process, it seems. Plus there almost certainly would have been younger > 125/250-bred riders who would have already been doing this on 990s, just > because it would have been more like what they were used to. And yet > what it appears we saw in late '06 was guys hopping on the bikes and at > speed immediately, not really losing anything from day one, and then > reporting the bikes were simply faster in the corners. That sounds like > a physics difference, they went into the corners and immediately > discovered they could turn the bikes more quickly, they didn't have to > fight the momentum of the bike as much as they were used to. They would > certainly then have to figure out how to fully optimize this change, but > its impact would be felt immediately, just as an increase in > displacement/power would be felt, first time they twisted the throttle. > The 800s still make a huge amount of power, and guys coming from SBs > would likely have continued to use an approach more like the 990s, a > style also more like they used in SB, where the power was similar to or > less than the 800s, but they really didn't, they were also cornering > fast enough not to lose lap time, and right away.- Hide quoted text - > > - Show quoted text - I think you are selling the top riders short on how quickly they can evaluate how a bike needs to be ridden. To get to the GP level they have probably ridden a lot of different bikes, many of which worked best when ridden in a specific way. When KR came to the GP class he brought the "rear steer" style from his dirt track experience. He was followed by others and eventually most 500 riders were doing the "rear steer" thing. There were exceptions. I seem to recall Chile still pushed the front a lot. But the "rear steer" style did not carry over into the 250s because they didn't have the power to pull it off. Buy carrying more corner speed the 250s often turned times that weren't all that far off the 500 times though. Some racers are better at it than others but the best ones actually change their style at different points in a race if needed to take advantage of how the tires are behaving. With that kind of ability to adapt how long do you think it takes them to get in the ballpark of how a bike needs to be ridden? My guess is that they would have it figured out in a dozen laps. There is undoubtably some difference in the mass and flikability of the 800s vs 990s, but I think the lack of brute power had a lot to do with the higher cornering speeds of the 800s. If you have ever had an engine fade during a long race and elected to soldier on you would know that different lines and techniques are needed to get the best times *on the same bike*. If the engine goes soft you stay on the gas further down the straight because you wont be going so fast and need less distance to slow down. And you want to take a smooth sweeping line that allows you to carry as much speed as possible because it takes longer to get back up to speed. The fact that you are carrying more speed in the turn means you are slowing less, so that also allows you to stay on the gas longer. Because the power doesn't come on as strong you can start feeding it in earlier. If you experience this once you will know in an instant what needs to be done the next time it happens. As for the invasion of midgets, I think the electronics have helped tame the beasts. It took a certain amout of brute strength on the rider's part to fight tank slappers and highsides. I remember when John Kosinski and Jimmy Felice tried to ride superbikes. They are both excellent riders that did well on 250s, but their light weight didn't help them on a superbike. |