Full fairing race bikes have great aerodynamics, and they are certainly much better than a car. Do you even own a bike or have any experience riding at high speeds? Not trying to bag on you, but the reason bikes slow down so quickly when they roll of the throttle is engine braking. They slow down really quickly at any speed if the rpm's are high enough. When you roll off the throttle at 13K it creates quite a bit of engine drag. At lower rpm's it's not as much of an issue. Go run your porshe up to 7K in first, chop the thottle, and tell me what happens

 

Have you ever raced a modded twin turbo? I can't recall any time that any stock bike beat me over 130 MPH, including some of my friends who own liter bikes. Off the line is a different story. A modded turbo will hit 200+ easily is a fairly short time.

 

Bill,

It is my experience most modded turbo's will not hit 200+ and definitely not easily. To attain this speed requires changing the final gear and/or raising the redline. To clarify this statement, speedo readings don't cut it. They read far faster than you are actually going.

 

Nope, sorry. Drag, as a coefficient of the frontal area, is
much higher on a bike than a car. Just the rider body
exposed on the sides causes much more drag proportionally
than a smooth car side. Exposed tires are another. Some
of the newer bikes, like they Hayabusa are much better
than naked bikes, but if you technically compare the volume
a car is pushing through it's frontal area, and it's overall
superior smoothness to that of a bike and rider, the fact
is as I state it.

Thank you. My first bike was a BSA in '68. I've owned 9,
raced an RD400 in the 80's, Owned the first 1300FJ in NorCal,
Keith Code Advanced SuperBike graduate, etc.

Not relevant to the case. Both the car and bikes rolled off
at high RPMs in a high gear, and the camera man in the car
would have to pivot the camera back as if he was filming a
pedestrian just to keep the bikes in the frame.

Find *another* professional engineer to get a second opinion
on the drag issue. If the task is minimizing drag at high speed,
no one is going to come up with a bike's shape. Here's an idea
though. This is a Super Turbo Mono Ecomobile with a top speed
in excess of 200 MPH with a BMW motorcycle engine. *This* is
what I'm talking about.
Joe

 

PS: The 'training wheels' retract automatically at 4 mph, and
go flush with the body.

 

I think alot has to due with *****, bikes are a hell of alot more dangerous, its easy to hit the gas the fly, but keeping up at high speeds in the corners can kill you pretty fast.

 

We're not talking about who can hit the highest top speed. We're talking about getting to 160+ the fastest. There is no doubt that bike are limited in their top speed by aerodymanics. Hence the creation of the Hayabusa and the Zx12.

Yes, I have raced TT's and host of other cars. None could hang. Can't tell you if the TT's were modded or not. I did get beat by a TT on my SV650 once, but that's a 90HP twin. Nothing has come close to my aprilia or my ZX10.

Joe:
There is a tremendous difference in rolling off the throttle at 13K vs 7K. You ought to know this as an ex track rider. There is a lot of engine drag at 13K. I haven't seen the video you're talking about, but a lot of riders sit up at the end of the race to relax and slow down. Almost acts like a drag chute and will slow you down very quickly.

Doesn't sound like any of the nine bikes you've owned (assuming your favorites were listed) can even come close to today's performance standard. You ought to take a modern superbike for a ride.

It is my understanding that drag on bikes only comes into play at hyper speeds (190 plus). And when I'm referring to bikes, I'm not talking about naked bikes or sport tourers, but modern liter super bikes.

Do you have any drag coefficient numbers for the TT or a bike? I have a hard time believing that a rider in a full tuck on a superbike has a worse drag coefficient than a TT. And even if it is worse, I can't imagine significantly so.

Did any of you watch the 700HP vette get stomped by a stock Zx10 and a busa on spray? I love our Pcars, but come on people...

 

All the bench racing aside I have never had any bike able to hang with me at highway speeds and then flooring the throttle. Those are the facts regardless.

 

Come on down Buddy. I'll race you from 60-150. I'll add you to my kill list Hell, I can start that race in first gear

 

Hi deputy. I just sold a zrx1200. I've aged away from
motorcycles. I'm too aggressive, and I've stopped healing
quickly . It would be interesting if bike manufacturers listed
their drag coefficients like car vendors do, but the figures
*would* be poorer than cars, and they would be much more
dependent on the size, attire, and tuck of the rider. Power-to-
weight ratio *is* bike's trump card. This is inarguable, and is
a constant in acceleration contests (ie: power-to-weight does
not change as speed increases). Aerodynamic drag increases
as the third power of the speed, so as speed increases, the
primary equation becomes drag-to-power. Because of the
geometric rise in drag, you often see hot cars and bokes that
get 20% power boosts gaining only a few MPH at the top end.
If we're talking about 0-XXX, bikes *do* have an advantage
(unless it's wet ). As XXX climbs, this advantage diminishes.
In contests of XXmph-YYYmph, cars advantage becomes more
important, and the motorcycle's advantage is diminished, eg
for 70mph-to-160mph races.
I don't think we really disagree that much... I'm just harping
on the physics...
Joe

 

I think we're on the same page Joe

Just some food for thought.

Stock ZX10 180 crank HP. 435 pounds.

Quarter Mile: 9.9's at 148mph.

Provided you're starting in the right gear at highway speed, should be no problem till at least 160.

 

You may want to watch some of the vids on www.garyjavo.com and watch a TURBO BUSA get spanked.

 

Deputydog,

Do you think your 148 is enough to put Killer Angel on your kill list? And yes, we can start the same race in first gear too.

 

Yeah, but how many people on this board have 1000HP TT's ?
Never said a car couldn't beat a bike, put enough HP in the equation and anything is possible.



Did you see the video I posted? The sprayed busa and the stock ten both take the supercharged vette from a roll on.

Who's killer angel CJV?

 

How many people have 275hp bikes? Point is, bikes are always at a disadvantage at higher speeds.