On Mon, 25 May 2009 12:23:56 +0300, Algis wrote:

> Paskaitom apie energija padangos deformavimui :)) Is to paties linko:

Bet ten nieko neparasyta kodel placios padangos sunkiau rieda.
Tik tiek, kad _siauru_ padangu bortus reikia labiau deformuoti, plius jie 
privalo buti is standesnes gumos, t.y. gautusi kad jie suvalgo daugiau 
energijos (nei placiu). T.y. gautusi atvirksciai.

Bet realybeje gerokai paprasciau: kiekvienos padangos darbini pavirsiu 
galima palyginti su gumine juosta. Riedant mineta juosta pastoviai 
deformuojama, t.y. lankstoma.
Logiska, kad kuo platesne juosta, tuo jos deformacija suvalgo daugiau 
energijos. Plius platesnes padangos turi standesni karkasa (kad dideliu 
greiciu jos centras neissipustu "kaip balionas") kas tuo paciu dar 
prideda pasipriesinimo riedejimui.
Tokiu budu pralosiama tai kas laimima del potencialiai didesnio bortu 
elastiskumo ir mazesnes deformacijos deka + dar virsaus.

> So do wider tyres give better grip?
> 
> If the contact patch remains the same size and the coefficient of
> friction and frictional force remain the same, then surely there is no
> difference in performance between narrow and wide tyres? Well there is
> but it has a lot to do with heat transfer. With a narrow tyre, the
> contact patch takes up more of the circumference of the tyre so for any
> given rotation, the sidewall has to compress more to get the contact
> patch on to the road. Deforming the tyre creates heat. With a longer
> contact patch and more sidewall deformation, the tyre spends
> proportionately less time cooling off than a wider tyre which has a
> shorter contact patch and less sidewall deformation. Why does this
> matter? Well because the narrower tyre has less capacity for cooling
> off, it needs to be made of a harder rubber compound in order to better
> resist heating in the first place. The harder compound has less
> mechanical keying and a lower coefficient of friction. The wider tyres
> are typically made of softer compounds with greater mechanical keying
> and a higher coefficient of friction. And voila - wider tyres = better
> grip. But not for the reasons we all thought.



-- 
In teh beginnin Ceiling Cat maded teh skiez An da Urfs, 
but he did not eated dem.