Stickboys in Moto GP

[Blue Mist]

The new Moto GP website click here (http://www2.motogp.com/en/motogp/index.html) lists riders' weights. It is no surprise that stick figures like Loris Capirossi and Valentino Rossi weigh in at 59 kg or 130 lbs. The heaviest rider listed is Sete Gibernau, 70 kg = 154 lbs. The surprising one is Dani Pedrosa at 47 kg = 103.6 lbs. Someone give that guy a sandwich! :)

I wonder if that sort of thing were to be handicapped as in horse racing, would it make any difference?

[DJ Down Under]

Well they are jockey's...and power to weight is important...so the riders weight is very important.

Here's a pic of Marco boasting about being bigger than Loris...they may be small but they're very strong and fit.

I've met Loris and he comes up to my waist...be really is hobbit size.

DJ

http://www.motorsport.com/photos/motogp/2005/val/motogp-2005-val-tm-0105.jpg

[Dallara]

This is always an interesting subject and fun to ponder about.

Years ago I was chatting with a bunch of race car engineers, two of which had extensive engineering experience in the old 500cc GP class of motorcycles. The discussion was whether CART and the IRL (two American open-wheel racing series for those of you not familiar with 'em) should have a rule where the driver was weighed with the car for the total minimum weight. The consensus was very quickly that a difference of 30 lbs. or so was significant to effect cornering perfromance to slight degree on these races cars, and a near 100 lbs. difference was very, very significant... And in those days Paul Tracy weighed damn near 100 lbs. more than some of the other drivers, like Cristiano DeMatta.

Now remember the cars in these series both weighed about 1,550 lbs.

But then the talk, as it often did, turned to motorcycle racing... and the line became far more blurred. We all agreed it a significant weight difference in riders should effect both acceleration and braking, but then we got to talking about wheelspin off corners and how a bit more weight up high would not only simply be more weight on the rear tire - aiding traction - but that it would also help weight transfer to the rear further reducing the wheelspin.

When it came to discussing cornering the line began to get positively fuzzy!

Certainly more weight would be loading the tire contact patch more, but then again a slightly heavier rider could get more weight off and to the inside, and hence move some of the weight lower, too, than a lighter rider. It was also postulated that a heavier rider might even have a significant advantage!

Why, you may ask?

Well, this is what we came up with... A race car like the ones mentioned above weigh about 1,550 lbs., and you add a 150 lbs. driver, so the total weight is around 1,700 lbs., with the driver representing approx. 8% of that weight... BUT HE DOESN'T MOVE AROUND IN THE CAR OR HAVE ANY WEIGHT SHIFTS THAT EFFECT HANDLING! He's strapped down tightly to the chassis so he has no more effect on the car than does the lead sheet ballast we used in the bottom of the tub to make minimum weight.

OTOH, a GP motorcycle at the time weighed about 325 lbs. Add a 150 lbs. rider to this and you get 475 lbs.... But then the rider represents nearly 32% of the total race weight of the combination, AND THIS PERCENTAGE OF THE WEIGHT CAN MOVE ALL OVER THE PLACE, WHEREVER IT WANTS, TO AID THE HANDLING OF THE VEHICLE PACKAGE!

We all laughed like hell and said that if we could relocate 32% of the wieght and mass of our race cars just about anywhere we wanted from corner to corner we would have cars that would appear to defy the laws of physics!

Of course, then the argument came out that a loss of rider weight on the motorcycle represented a larger percentage of weight and mass loss that a lighter rider would have to be an advantage... And the battle started raging anew. No final consensus was ever reached...

At least not before the scotch, beer, etc. took over and had us all pretty much not making any sense any more, but it was a fun and enlightening discussion.

I know of no definitive study to determine if rider weight would be a significant factor to MotoGP lap times but the various points ot consider are nearly endless, like:

Lighter rider = less tire wear due to loading, but does lighter rider = more tire wear because of more wheelspin?

Heavier rider has more muscle mass = stronger and more able to force more violent control movements, but does heavier rider with more strength = more tire wear due to more heat in the tire from more violent control inputs and deformation of the tire contact patch?

Heavier rider = more sprung weight percentage to unsprung weight so the wheels should better follow the track surface, but does heavier rider = more suspension unit heating and hence loss of damping efficiency and so more tire wear due to suspension movement?

Smaller, lighter rider = less frontal area which should net less frontal area drag and more top speed, but does bigger, heavier rider = more *teardropping* of shape and provide smoother airflow off the back of the bike which equates to less parasitic drag from there being less of a negative pressure zone behind the rider?

The list goes on and on, and the answer may look simple on the surface, but becomes more and more complex the more layers of the onion you peel.

Still, fascinating stuff...

Cheers!

Allan (Dallara - NACD)

[DJ Down Under]

Good one Dallara....is this why you get no wheelspin at all on your bike....:037: .....just kidding..:icon_biggrin:

It's the same in Formula One...they're all midgets....

Mark Webber (the only Aussie in F1) had a very hard time getting a drive..partly because be was a bit too tall...and only an inch or two more than the others.

It's a vicious circle...they make the bikes and cars around small riders/drivers and you need to be able to fit the package...

..also so they can swap cars and bikes if their team mate crashes or they change teams.

DJ

[Bones]

Great discourse over those beers and scotch I will bet. I will also bet that given the crowd you were with, there might have been a bit of heat in those discussions, especially when the libations got going.

The closest I ever got to "bench racing" discussions at those really meaningful levels were for about a half hour with Freddie Spencer, twice and with Kevin Schwantz for about 2 hours one night.

Talking with Freddie about this stuff is like talking to a college professor about it. He is extremely analytical, really, really understands the engineering and equations and , of course, has applied all of this successfully. He had been "criticized" in the past for having a less distinct style of riding than some of the other motoGP superstars. But he could also get on a new bike and run lap times within a hair of course records within the first few laps. The guy knows his stuff and can explain it in a way that is NOT new age bullshit. Based on what and how he teaches, it is clear that he nuances every available way to control the bike. But, he is not necessarily the most relaxed and open a guy to hang with when compared to .......

Kevin Schwantz is just one of the most down to earth, easy to talk with and funny guys around. As I had the good fortune to be sitting with him at a Mexican restaurant just chewing the fat, it suddenly occurred to me that "hey, this is Kevin Schwantz for crying out loud, and he seems to actually be interested in talking with me." I think he really does understand riding WAY more than he is able to convey in conversation. He is quite self depricating in a disarming way. Then he gets on the bike and blows everyone away.

He made the comment "you know, regarding feathering the rear brake....well, some guys do it well. It can settle the suspension, for sure. But I used the rear brake in competition exactly three times. I crashed all three times. But they wouldn't let you remove the damned thing from the bikes, so after that third crash, my crew would wrap wire around the pedal so if I tried to push on it, it wouldn't work. I was known for a bunch of things in racing, but finesse wasn't really one of them....."

Those discussions can lead to some real learning....you just have to make sure the guy(s) you are learning from know what the hell they are talking about.

Jeff

[Sir Limpsalot]

One of the very best Isle of Man TT racers in recent years (or, indeed ever) was "big" Dave Jeffries. Known as DJ to legions of race fans. Dave went about 6' 2" and must have been 200 lbs (plus). When nearly all succesfull racers are stick thin, shorties it was something of an enigma why Dave was so fast. He towered over the opposition in every sense. He dominated the 1000cc classes and went surprisingly well in the 600cc too. One theory often offered was that his size and strength meant he could "Gaffer" (or boss) the bike into doing what he wanted, very important on the "Island" when even the best handling bikes are prone to weaving/wobbling due to the high speeds over imperfect roads. That wouldn't explain his speed on "normal" circuits though, last time I saw him ride he won the 1000cc Superstock race at Brands Hatch by about half a lap.
Truth is, I believe, that whether his size was an advantage or a handicap he was just so naturally talented that it didn't matter.
Sadly, DJ died in a very high speed crash on the TT course caused by an oil spillage.
Si

[DarthRider]

Jeff said "...you just have to make sure the guy(s) you are learning from know what the hell they are talking about..."

When I took Reg Pridmore's CLASS school, we were gathered up waiting to start the first classroom session. Reg came in, said good morning, then asked, "How many of you know how to ride a motorcycle?" All hands went up.

Then he asked, "How many of you tought yourselves how to ride?" Maybe a third of the hands went up.

Then he asked, "How many of you learned how to ride from a buddy, your brother, your nieghbor, or the guy you bought your first bike from?" Most of the other hands went up..

Then he said, "Gentlemen, I'm sorry to tell you that every one of you learned wrong and most of you don't know how to ride a motorcycle." Smiles, spirits and hands dropped, replaced by muttering and grumbling.

Then he added, "But cheer up guys, because today you will learn how to ride a motorcycle and you will learn to do it well!"

Every one did cheer up and all but one did learn to ride their motorcycle. This poor clutz ran off the track and flopped over in the mud on all three laps he was allowed to run before they refunded his money and sent him home!

When I took the CLASS I had been riding for 35 years and had raced about 10 of those. But in describing CLASS to others I am always quick to tell them that was the day I learned how to ride motorcycles.

I was with 5 other guys on Ducatis from N. Texas. We stayed on in the Texas Hill Country for three more days and gave ourselves a "grad school" in what we had learned from Reg, trying all the new things, practicing, critiqueing ourselves and each other and continuing the learning. What an experience.

And we learned one other very important thing as well, "...you just have to make sure the guy(s) you are learning from know what the hell they are talking about..."

Dave

[Bones]

Darth,
Indeed!

The funny thing is that no matter what level you find yourself at, there is always, always, some moron next to you.

I went to Freddie School (multiple times) with enthusiasm and focus, but the proper dose (I think) of humility. The last time I was there, there was a guy in the class who CLEARLY knew more than Freddie, Jeff Haney, Jason DiSalvo, Nick Ienatsch, and Dale Keiffer. And he made sure we knew it. I thought to myself "Why oh why is there always one of these guys in any class or group endeavor I have ever pursued?" Because human nature makes it so.

While we were suiting up after one of the classroom sessions, this guy is loudly proclaiming to the rest of us in the locker room "look, a motorcycle is a motorcycle. You ride 'em all a little different, but they can all be made to go fast. I can make a Harley go around the track as fast as a sport bike. It is all in how you ride 'em." OK. I guess I must have missed that day in physics class in college, because I am thinking, gee, you sure can't make a Cadillac Eldorado run like a Ferrari, but what do I know?

Interestingly enough, our friend was found to have made a huge cloud of dust on the infield of the track as he surfed a CBR600RR off the tarmac. I really can't bring myself to wish ill will on even the largest of assholes, but I must admit with embarrasment that when the guy standing next to me said "Gee, what a shame it is that HE crashed. We could have learned so much from him" I had to chuckle.

There is always one in every class isn't there?

And if you know when to recognize that someone might know more than you on a given subject and are smart enough to listen carefully, it is amazing how much you can learn. Simple concept, really.

Jeff