Drifting doesn't really have to do with heating up a tire to obtain traction. It serves two purposes.

1. As a late braking technique, it makes the width of the bike larger to potential passers. If they are trying to pass on the outside, your bike just became a foot or two wider.
2. You can apex a little earlier as your bike is turned through the corner farther than if you didn't use the technique.

Heat in the tires is a problem in the first laps as they are cold, and then as the race goes on, the tires deteriorate. Racers don't want any extra heat than they already get.

Also, your argument refers to the fact that streetbikes are experiencing problems in being too light, and can't use the extra horsepower. This argument is not correct. MotoGP bikes are way lighter than the AMA SBK bikes, and put out 200hp or more. There is definately a balance. Weight is just as important as HP, as they both play major roles in tire life. For instance, Honda is experimenting with a 6 cylinder MotoGP bike. Supposed to give an extra 40 hp, but weight 40 lbs more. They are concerned with the handling characteristics of the extra 40 lbs, and most importantly, tire life. Mid corner traction is going to wear more, and lighting up that 240hp or more is definately going to shorten tire life.

I agree that dirtbikes receive a ton of R&D money, and quads very little. ATV's would be light years ahead of where they are now, if they had similar R&D budgets, no question. It is a very exciting time in the sport/racing quad segment with all the new models, and Yamaha dropped the bomb with this quad.

Even with the caveats in the article in DirtWheels, the fact that a YFZ can stay with a YZF is remarkable.

However, the dirtbikes you can buy today, are so much farther ahead than bikes 10 years old. I know it seems tough to imagine a much improved dirtbike in 10 years, I can guarantee you there will be.

Hopefully, with this renewed interest in the sport/racing quad industry, we can get the same type of jump in machinery. Not like from 1990-2000......

 

I'm not sure what you mean by drifting, but I know that in the sport bike racing world there is a techique called counter stearing where you lay on the gas in the corner and the back end brakes loose and slides around, a point shoot type of stearing. You literally stear with the back end and less with the front. This is also one of the most difficult concepts of sportbike racers to learn to do, espially since most sub liter bikes do not have the amount of torque required to brake the back wheel loose. In the 600, and 750 class to my knowledge this technique is not used. The benefit you get from this technique is that you don't have to carry as much braking into your corners. You also save your brakes as well, but can loose your tires earlier.

 

rennym, also this is still not actually a fact, because I believe it was ward who got his factory team a couple years ago to lower his overall hp numbers of his bike because he said he would rather run with better gearing then having unuseable excess hp. As far as the GP bikes having incredible hp numbers that is true but there hp numbers are not as useable as inline 4's. The 2 stroke engines can reach greater peak hp outputs but can not sustain them as easily as the SBK series bikes, matter of fact I do think the SBK bikes put out alot more torque as well. It kind of goes and relates right back to the 4 stroke vs 2 strokes argument in the ATV world (same argument but much larger scale). The Moto GP bikes might make more power and be lighter but there power isn't as useable across the overall power curve. And they can only use that much power anyway once they are at speed, There is no way a moto GP sport bike could use 200hp at stand still or lower speeds it would be a death trap. I use this same anaolgy when comparing dirtbikes and ATV's because you can surely increase the hp on a MX pro bike, but it wont do you any good unless you are carrying enough speed to make a difference. Thats why most LT500's zilla's and cr500, kx500, yz 490's are mainly only utilized on high speed desert courses and comps. If you cant maintain the high speed there is no reason to have the higher hp and torque numbers. At lower speeds you will just spin tires uncontrollably. Thats why I say that I just don't see anything in the way of major changes that will revolutionize the dirtbike industry. I think they are pretty much peaked out. Think about it, even since 1995 there has been vary little changes in the over all dirtbike geometry and frame. I think the last enormous change was when they went to all aluminum frames and that was somewhere around 1994-1996. Since then nothing suprising, nothing revolutionary. I don't see any evidence how dirtbikes have improved all that much. Same basic frame set-up, tire wheel gearing overall specs. Nothing to suprising in the suspension area, the engines have pretty much output the same hp torque chars, same ergos. Am I missing something here? Where are all these major changes in the last 10 years? There have only been two that I can think of, the aluminum frame change, and the move from 2 stroke to 4 stroke tech.

 

Two techniques.

The one I was describing is used in entering and apexing the corner.

Another is when you are exiting a corner (post apex) and spin up the tire. Every supersport machine has enough power to spin up the tire on exit. I have seen this second technique from Nicky Hayden, especially in the first couple of laps of some of last years AMA racing. He was doing it because the tires were cold, and no one else had the confidence to do it, especially on the first lap! He is known as a championship caliber dirttracker (as shown by his one or two dirt track races last year when he dusted everyone), and races with this brothers around the dirt track at his home.

You still need to brake into a corner. Either through engine braking, or using brakes. You will also see much more concern from racing teams over tire life, than brake pad/disc life. The pads/discs last much longer, and technology is very good these days to deal with the heat build up. Not saying that brake pad/disc performance is not a worry, just that tire life is a greater concern.

I don't understand your MotoGP machine comments. The fastest bikes on a track anywhere are MotoGP. The top riders all ride 4 stroke machines. Honda's RCV five cylinder four stroke machine decimated the competition last year, and is dominating again this year (does help that Rossi is riding one). But Yamaha is not that far behind. Pretty damn close....

But even when MotoGP were 500cc two strokes, they were still faster than any other bike on a track. Just the 4 stroke generation of MotoGP has a broader torque curve, more usable power, and more peak power.

But the simple argument that bikes can't use more hp and less weight is not correct. There is definately a balance, and you can't have a million hp and ten pounds, but if the MotoGP teams could find 100 more hp and not cost them any more weight, they would be after it like crazy.

With all the money poured into dirtbikes, there is bound to be improvements. Not everyone is running an aluminum frame. Pretty sure Yamaha, Suzuki or Kawi don't run aluminum, although I have seen some super exotic factory race bikes from those manufacturers that do. Just Cannondale (RIP) and Honda produces (ed) them for the masses. In fact, Honda had to soften the frame from it's first generation ones as they were too stiff and harsh. In any case, light weight materials, suspension, engine power, torque, rev characteristics, brakes, tires, and geometry will all play a role. It's where the money is......

 

The aluminum frame CR250 debuted in 1997. The YZ400F debuted in 1998. The YZ250F came out in 2001 I believe. But I guess that not "revolutionary" because its a bike and not a quad. Funny, cause if it wasn't for the development of the YZ400F, there would be no YFZ450. Anyway, since then there have been numerous new models of moto-x bikes coming out every year. Maybe it would help if you did some research on the dirtbike industry instead of just forming and opinion based on no solid facts.