Hollow Wheels in F1?

[ginsu]

Wow, didn't know anybody noticed this thread.

First, let me repeat. OZ RACING have been using hollow wheels on the SAUBER F1 CAR for several years!

Now, you can argue the benefits of this design as much as you want, but unless you know specific air volume measurements you cannot actually get a number to determine the change in tire spring rate. However, I am confident there will be a change in tire characteristics if you change the internal air volume. How much and to what benefit is hard to say, but OZ Racing developed wheels for that purpose, and they have been used/developed/updated for 4+ years, so they must do something beneficial

Personally, I think the 2011 Sauber is doing well in part because of these wheels and their interaction with they VERY SENSITIVE Pirelli tires. The air volume difference may not have made a big influence in past seasons, but it seems likely that the Pirelli's are a very different animal.

Also, I've been hearing that the RB7 has updated its wheels for Barcelona, and they are sponsored by OZ Racing, so interesting if we see them switch to the hollow section wheels.

Oh yeah, for anybody having difficulty imagining why the air volume would effect the spring rate. Without getting overly technical (I can if we need to), the cause is due to the Ideal Gas equation (pressure is inversely proportional to volume), the effect is a NON-LINEAR SPRING RATE. For example, due to the non-linearity, a 20% increase in air volume could have an 80% change in tire characteristics.

Ideal Gas Isotherms

Spring rate change

[ginsu]

Finally, they crashed the car with the hollow wheels so we have actually public proof of their very special wheels.

Now, Sauber are obviously doing very well this season. So well, in fact, it deserves some closer scrutiny.

If the biggest change this year are the tires, and Sauber goes from being mid-pack to nearly beating Marc Webber's Red Bull at Monaco, I would think somebody on a struggling team would have a closer look at those very special wheels they are running.

HINT HINT!

BTW, such a let down to see this car crash and expose their hidden secret. I was thinking the whole time, "they will finally see what I have known for years, I wonder what they will think?" I patiently waited for Coulthard or Brundle to comment on those nifty wheels...but sadly, they are too stupid to notice something so obvious. Oh well.

[Richard]

Having good mechanical properties in the rim area is important, since this is the part of the wheel that most often takes impacts. A forged or spun rim section is less likely to fracture than a cast rim section under impact. A bent rim can still hold tire pressure, while a cracked rim will not.

We can see from the pics above that the Sauber wheel has lost its rim, appears to be peeled off.

[PhillipM]

Off road racers have been running hollow wheels for almost 20 years

They're much better strength/weight but they do, obviously, require more volume for the spokes.
They do reduce the tyre spring rate slightly from the increased volume vs displacement but it's not a lot tbh.