On 3/13/2019 7:46 PM, John B. Slocomb wrote:
On Wed, 13 Mar 2019 16:40:16 -0700, Joerg
wrote:

On 2019-03-13 16:09, Mark J. wrote:
On 3/13/2019 3:36 PM, Joerg wrote:
On 2019-03-12 18:33, James wrote:
On 13/3/19 2:07 am, Joerg wrote:
On 2019-03-10 06:34, wrote:
I keep reading see all the bikes coming out and basically all disc
brakes. I cannot believe rim brakes are going to be gone but maybe I
am just kidding myself. I frankly hate the disc brake look and
certainly for a long time parts will be around but are these rim
brakes a dead deal.


Disc brakes are simply better. Take a look around around automotive
and motorcycles. How many new cars and motorcycles are there that
still have drum brakes in front?

On Sunday I experienced the umpteenth reminder why rim brakes are
inferior. We had to cross some unpaved area on the road bikes and it
had rained. Muddy. Afterwards a descent on pavement, I reached in and
after the usual and expected one-second of zero brake action the rim
brakes came on. There was an awful grinding noise, you could literally
hear aluminum being eaten.

If I ever need a new road bike it will have disc brakes or I won't buy.


A bit of wet mud isn't the end of rim brakes. Hose them off and they'll
be fine.


We have lot of bits of wet mud. The rims of my first MTB looked
horribly grooved after the first 1000mi. Trails here are really muddy
in winter.

The other advantage of disc brakes is that they can be cooled off on
long descents with a quick spritz from the bottle. Phssst ... HISSSS
... and on you go. No need for a lenghty cool-off period.

What does that do to the temper of the metal? E.g. will it
harden/embrittle? Not sure if this is a problem, but worth checking.


I doubt it does much because I do not ride them until they glow white.
The only side effect I noticed was that they are noisy the first mile
afterwards. No squeal but more like HOOOO. Loud. So in areas with lots
of cattle this isn't a good idea.

You must be using shoddy brakes. F1 disc brakes run red hot
https://www.pinterest.es/pin/35114072064401057/
And not only that but F1 brakes use carbon fiber discs and are so much
lighter in weight then old fashioned metal discs.

As for glowing white hot? That would be in the 2,300 - 2,700 degree
(F) range and, I might add that steel at 700 degrees (F) has lost
about half of it's strength. At 2,000 degrees it must be similar to
wet paper.


Nowhere near those temps. Something around 100C will give
steam. Bicycle discs are stainless at any rate. The pad
material will debond from the back plate well before any
temperature effect on the disc.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971