Z4

[NickW]

Just read a write up on the BMW Z4. It has "drive while flat" tyres, and no spare wheel. Whats that all about? Any physicists out there who can explain why driving on a flat wont ****-up the wheels?

[daydreamer]

Few ways of doing it - The easiest is to invert the rim so that the rim doesn't sit on an edge with a flat tire, essentially making the wheel rim look like a motorbike tire (sort of). Other systems use a tire with a really strong sidewall, so the load transfer is stright through the rubber when there is no air in the system. Still make a mess if you lose your tire though.

Yes, I'm a geek!

Looking for a simple picture to explain it all, but my 60s googling limit has run out.

[dennisthemenace]

Ugly car burn the factory down so they cant make any more

[NickW]

it is ugly. why cant they give these bloody things a boot so they look a bit balanced. still, at least you dont need a spare wheel...

[dennisthemenace]

looks like a nike clown shoe now

[joust]

He's a link to most of the systems around and how they work

www.orbweb.net/autoshop247/tyre_talk/11_latest_trends.html

[apache]

c'mon guys, everyone complains about bland look alike cars and when something different comes along it's slated as ugly, I like it....not a fan of panzer wagons either

[iguana]

I quite like it, it looks like a beefed up S2000 from the rear 3/4 and that ain't bad IMHO. A Fiat Multipla is ugly and so is the boss eyed Morgan Aero 8, but the Z4 is just different. The new 7 series however uggggh!

[ErnestM]

Just read a write up on the BMW Z4. It has "drive while flat" tyres, and no spare wheel. Whats that all about? Any physicists out there who can explain why driving on a flat wont ****-up the wheels?

The Goodyear run flats have been available in the US for quite some time. Essentially there is a change/stiffening of the sidewalls. This allows the tyres (tires over here) to still operate without the wheels slicing them off. When first introduced the speeds were relatively low. However, most run flats are rated at "55mph for 100 miles when flat" at this point.

Cheers

ErnestM (not a physicist, just a consumer )

[Bonce]

So how do you know when you've got a flat?

[GregE240]

Well, the tyre looks deflated and the car handles like a pig above 55 ? But in the US you can only go above 55 on Interstates so you're right Bonce.

Saw one over in the US whilst on holiday - pig ugly. Mess of lines on the side profile - looked awful. Given that most sportscar buyers buy a car with the idea of looking out of their front window at what's on their drive, I can't imagine Z4 owners doing that a great deal, if only to think "Why ?"

[Paul V]

There is a pressure monitor built into th car, so it puts a warning light on when you get a flat!

[Gargamel]

Hmm - rover sd1's used to be fitted with Dunlop denova's in the early 80's - ran for 100 odd miles with a flat...

so not that advanced then.

as to the rest of it - I like the idea of software that allows you to step the back end out, a little, a medium amount - or as much as you like.... mad - programmable fun factor ....?

[K27]

I work just around the corner from a BMW dealer.
last week on my way home I saw a spond new one get smucked, some one pulled out in front of him,looked like a write-off, it also looked better after the crash.