Sheldon Brown writes:
Somehow these threads drift off into unrelated topics, probably to
defend a defenseless position that no one else knows the writer
holds until defended here.
You were the one who brought up the issue of using a hammer and
punch, with your categorical statement that "I don't believe it was
ever appropriate."
I still believe that because, as I mentioned, I never used that
method with those old brakes that did not have wrench flats as the
later Campagnolo brakes did. I got to see many different brakes in
the days when the brake design concept was as volatile as it is today
but with less understanding of the problems being addressed.
The subject of this thread was centering a modern high quality
Shimano brake, not steel caliper Raleigh brakes of decades
ago. Even those brakes recognized the problem and made spring
bosses pressed onto knurled center bolts that were pressed in place
to assist adjusting brake position.
That's not correct. The "spring bosses" were either threaded onto
the center bolts (for the cheaper models) or were a slip fit over
the center bolts. The part involved was a single casting, nothing
knurled, no way to rotate the front vs the back.
Some were, while others were one piece and yet others were knurled and
pressed into the base block. That doesn't change the cause of brakes
retracting asymmetrically with longer use, primarily a result of
friction at the spring contacts... the subject of this thread if I
recall correctly.
Let's leave the hammer and punch in the historic bin. There is no
place for them on any recent aluminum alloy brake caliper.
That's true.
Just the same, it is worth mentioning up because the method is still
in use in bicycle maintenance on the basis that it had been done
before by noted mechanics... much like tying and soldering spokes.
These things live forever.
Should they be challenged or is bicycling lore the poorer for it?
We could delve into the sham of Gore-tex (R) next.
http://www.thebackpacker.com/beginners/goretex.php
just for starters.
Jobst Brandt