On Sep 8, 12:42 am, Eiron wrote:
Andre Jute wrote:
Those brakes aren't dodgy, Don, they're hyper-competent; what I forgot
to add is that they have a built-in modulator. They stop the one-
eighth of a ton of me and the bike and light touring gear from thirty
kph in 11 feet. I know, because I chewed up a pair of tyres while I
practiced that one to perfection. But I agree with you, for casual use
those roller brakes are overkill.

A fat man on a granny bike braking at over 1g!

Find the fat on my pic overlooking Dunworly Bay, several places on my
bike pages, and I won't put you in hospital when I run into you. You
mean an opa bike, not an oma bike (or granny bike as you ignorantly
have it). You wouldn't know either if you saw them, sonny.

Don't the laws of physics apply in Eire these days?

Same as everywhere else. Here is a reliable authority on the subject:

"The maximum braking force that can be applied to a vehicle through
its wheels -- the mass of air having its own retarding force -- is
limited by the friction between the tire and the road, and is equal to
the weight of the vehicle multiplied by the coefficient of friction.
On a dry pavement, this coefficient could be as high as 1; with a
coefficient of unity, retardation would be 1g or 32.2ft/s^2 and the
stopping distance in feet would be V^2/29.9 where V is the speed in
mph. I must stress though that this is on an ideal surface such as
does not exist outside a test facility..."
(p98, Designing and Building Special Cars, by Andre Jute, Batsford,
London 1985)

The math is developed elsewhere, where you can go find it.

--
Eiron.

Do come again, Eiron. It is always a giggle when you take yourself
seriously.

Andre Jute
Impedance is futile, you will be simulated into the triode of the
Borg. -- Robert Casey