zlacker

>>LinuxB+(OP)
So much WTF in this article, like the regenerative braking thing as if the torque for both regular braking and regenerative braking doesn't have to be put through the tyres to slow things down.

I definitely buy people with EVs hooning it around the place wrecking their tyres. It is really easy and fun to make use of all that torque. But it's not actually required.

>>mehele+H2
By design, braking introduces drag onto the brake disc and in turn creates drag on the wheel. This drag is in opposition to forward momentum and so the rubber of the tyre flexes and gives to these forces a little at a time - resulting in slowing your forward momentum.

A rail car without rubber takes 10x-50x the distance to brake due to steel on steel friction.

Rubber is consumed from the tyre during acceleration, deceleration, and turning. Little rubber granules will roll off. The only time this isn’t happening is when the tyres aren’t in motion.

This is why you bring extra tyres to track day.

>>reacto+G4
In motion the friction coefficient of rubber on asphalt (0.67) is not that far off from steel on steel (0.57) according to the internet [0]. That orders of magnitude difference in braking distance is more a result of train cars weighing 30-80t.

This comment does feel like talking to ChatGPT though, with the detailed clarifications the discussion didn't really require.

[0] https://www.aplusphysics.com/courses/honors/dynamics/images/...

>>buran7+27
It doesn't change much, but note that unless you've blocked your wheels (and you have no ABS), you need to check the static coefficients. Wheels work so that from the point of view of the wheel the asphalt is still (i.e. there is no translation, only rotation).

This is why blocking the wheels increases braking distance: you suddenly have to deal with a much smaller friction coefficient.

>>bonzin+7b
Well that and the fact that rubber melts and that changes some coefficients. Nothing about braking is as simple as one formula.

P.S. Isn't the static coefficient calculated for a stationary object trying to move against a surface? In a wheels locked scenario the wheel is sliding so the dynamic coefficient is the one to look at, accounting for the changed material properties of the heated/melted material.