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John H[_2_]

On Tue, 11 Jun 2013 14:07:14 -0700 (PDT), wrote:

On Tuesday, June 11, 2013 3:23:55 PM UTC-4, iBoaterer wrote:
In article ,

says...

On Tuesday, June 11, 2013 8:54:07 AM UTC-4, iBoaterer wrote:

In article ,

says...

There must be some reason that nearly every track record is held by a

4 wheeled vehicle.

Cite?

Barcelona 2005

Formula One - Fisicella's Renault - 1:15.641 fast lap.

MotoGP - Gibernau's Honda - 1:42.337 fast lap.

PHILLIP ISLAND GRAND PRIX CIRCUIT LAP RECORDS

OUTRIGHT SIMON WILLS REYNARD 94D 13/02/2000 1.24.2215

FORMULA 4000 SIMON WILLS REYNARD 94D 13/02/2000 1.24.2215

PHILLIP ISLAND GRAND PRIX CIRCUIT

MOTORCYCLE LAP RECORDS

MotoGP Marco Melandri (Ita) Honda RC211V 1:30.332 16-Oct-05

Pole : Nicky Hayden (USA) Honda RC211V 1:29.020 16-Sep-06

A couple of results from a quick google. You can do the rest of the work.

Pretty much the only tracks where you'll find faster times for bikes are the tracks specifically designed for bikes. Cars obviously enjoy enough of an advantage from their superior traction, brakes and downforce that it negates the bike's advantage of less mass and better power/weight ratio. Not by a lot, but 6 - 27 seconds (the diff in the examples above) is a lot on a track.

Have fun.

Let's see. All tracks made exclusively with cars in mind.

Tracks that have taken special pains to cater to a bikes special needs are faster for bike. Take that advantage away, and the car is faster.

Now, how about
REAL cites? How about the physics behind your ASSumptions? Superior

downforce??? You DO realize, don't you, that a motorcycle, when it leans

INTO the curve is keeping it's CG in line with the forces, while a car

isn't, correct?

You do realize that the CG of the bike, when leaning into a turn, is attempting to push the tire ACROSS the pavement at the angle of the lean? Meanwhile the car's down force is pushing the tire directly down into the pavement. Keeping the downforce perpendicular is a good thing.

Besides, the bike couldn't corner if it didn't lean to keep the CG in line with the cornering force... that's what keeps it from flipping over. That's also what causes the increase of slip angle and traction loss.

One of my brothers was a motorcycle cop in Richland, WA. He was chasing a car through a residential
area, the car making turns almost every block. He wasn't able to outrun it, but he was able to keep
pretty close. And then they went around a corner where the homeowner's sprinkler was wetting the
street. Down he went.

John H.
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Hope you're having a great day!