At 02:10 PM 7/4/2010 Sunday, Alistair Bell wrote:
>oh pish posh David :) Maybe its because the English pioneered disc
>brake technology you have a bias on the 4th.

Alas, you have smoaked out my motives.  Dr. Maturin, will you ever forgive me?

>Mid 50's jag, triumph, healey... and even the French in Citroen.

Even?  Citroen was about the most advanced marque around,
engineering-wise.  2CV aside, and even it had driver-adjustable
headlight aiming.

My Sunbeam Alpine (Series II, built '63) had drum brakes all around,
along with its knee-action dampers.

>as to the comment that they are not needed on the rear wheels because
>the rears do relatively little braking, you must love the poorly
>adjusting Vanagon drums a lot to trot out that excuse :)

That must be it!  I must say they adjust very well if you grease them
occasionally, and unlike many US designs you don't have to apply the
brakes in reverse or use the parking brake to obtain the adjusting effect.

Confession: the brakes on my "new" '89 have not been greased since I
got it a year-plus ago, and the adjusters are sticky.

>discs are simpler, they apply force predictably, and they do work
>well with ABS... lets see a drum brake ABS system, anyone?

I'm sure it's been done, but I take your point.  Quite aside from the
point, my insurance company (USAA) has reduced to discount for ABS to
almost invisible level, 2-3 dollars a year, because statistically
they make no difference in the accident rate.  Not that technology
for its own sake is bad, it keeps the repair shops busy.  ;->

>Sprung/unsprung weight argument is a canard. If you worry about that
>you design to have the discs to be inboard, sprung weight.

It's been done.  Fairly recently on the US Army HMMV if I recall
correctly.  I believe they also had some cooling issues resulting in
rapid brake wear.

>  On
>passenger cars the difference is less important, especially when you
>consider the tire and wheel weights nowadays (talking about the trend
>to large diameter wheels).

Hey, I was just mentioning what Smokey Yunick and his buddies were
mumbling about back in the '60s.  I hardly knew what unsprung weight
was then, or why.

>happy 4th to all you Yanks

Why thank you kindly.  I shall be taking the air (and my camera and
tripod) tonight for the City of Providence's band concert and
fireworks display, along with my young nephew from Seattle and my
professor friend who was my dad's executive officer in The War.  We
shall drive there in a Vanagon, at least as close as we can find
parking; and return in it assuming we can find it again.  Even as we
speak the oldest Independence Day Parade in the country is being held
nearby in Bristol RI, which among its other sterling qualities (yacht
design and construction, for example) was the seat of the extensive
slave trade which made so many Rhode Islanders rich a number of decades later.

Yours,
David