6 replies to this topic

[Robbie]

There was a lot of discussion about the front Michelins during the German GP. They're wider than the Bridgestones.

My question: if tires are wider doesn't that give them more surface area in contact with the ground, and doesn't that retrieve something from what is taken away by the grooves?

Crudely put: are the wider tires nearer to slicks (in terms of contact with the road)?

[DEVO]

ARTICLE 12: WHEELS AND TYRES
12.1
Location:
Wheels must be external to the bodywork in plan view, with the rear aerodynamic device removed.

12.2 Number of wheels:
The number of wheels is fixed at four.

12.3 Wheel material:
All wheels must be made from an homogeneous metallic material.

12.4 Wheel dimensions:
12.4.1 Maximum complete rear wheel width : 380mm
Minimum complete front wheel width : 305mm
Maximum complete front wheel width : 355mm
Minimum complete rear wheel width : 365mm
Maximum complete wheel diameter : 660mm
Wheel bead diameter : 330mm (+/-2.5mm)

12.4.2 These measurements will be taken horizontally at axle height.

[Robbie]

Thanks for citing the rule, Devo.

It seems to me that what Williams and Michelin have come up with together is a whole new idea for a racing car (Ferarri and Mclaren being rather similiar, though perhaps not in the finer details).

Have they decided that the incredible power of the BMW needs the extra traction on the front? And the extra drag the front wheel produces (mentioned by Captain Cook) requires very different aerodynamics. (Williams have been keen to hide the wings from time to time.)

I'm not sure if this analysis is correct.

[PDA]

Speedvision did a piece about hte difference between Bridgestone and Michelin a coule of races ago. As stated above, Michelin get a bigger contact patch, but with a drag penalty. Also, becasue the shoulder of the tyre is much more square, the wheel must be run more upright, so the quite heavy positive camber used by e.g. Ferrari, cannot be used by e.g. Williams.

[AdamLarnachJr]

I dont mean to be a smart a$$ but dont the Bridgestones requrie more *negative*camber because of their rounder shape? Thats why the wheels are always like this //=O=?

[moog101]

it's negative camber

[MN]

Originally posted by AdamLarnachJr
I dont mean to be a smart a$$ but dont the Bridgestones requrie more *negative*camber because of their rounder shape? Thats why the wheels are always like this //=O=?

Yes,
Take a look at those photos taken at Spanish GP this year.
It suggests Bridgestone users have more negative camber compared to Michelin and out side of Bridgestone front tyres remain unused.

Bridgestone front tyre


Michelin front tyre