Brucey wrote:horizon wrote:Just a gentle reminder that the thread was really asking why now? (though I accept that isn't clear from the thread title). Remember, they had over a hundred years to get their act together.
A hundred years? -not really; the 'invention of the disc brake' a hundred years ago did not result in the widespread adpotion of disc brakes on any vehicle, for a long time. Aeroplanes were early adpoters, racing cars (1950s) road cars (60s and 70s), motorcycles (70s) railway rolling stock (~90s?) and bicycles all followed later on.
In your first post you describe disc brakes as being 'de rigeur' now, but (outside of a few niche applications) I'd dispute that. There are many more bikes sold with brakes other than discs....
Presently they are a viable alternative to other brakes at a reasonable cost, and (by association as much as anything else) they suppose that they
are going to work a lot better than the 'old fashioned' alternatives.
cheers
Ah yes. The High Speed Train, developed in the 1970s. The thing about the HST isn't so much the ability to go, but the ability to stop.
The big deal was that the HST with Mk 3 coaches can stop from 125 mph in the same distance as all the other trains at the time can stop from 90 mph. This meant that the HST could travel at 125 mph without any need to change the distances between signals.
As for how it achieved this: it went from tread brakes to disc brakes, and had a form of anti slip braking. The (early) electronic actuation was also part of the package. The braking capability was what really made it a success.
Modern rolling stock now routinely uses disc brakes, either wheel mounted or axle mounted. I think with this sort of thing, once one bunch spends the time and money to develop the technology, the entry price drops for everyone, so it becomes more widely adopted. Similarly, traction with electric motors additionally uses the motors to get dynamic braking, as with disc brakes, once the technology had been developed, it was more widely used. In that case, the electronics and software to blend dynamic and friction braking also helps.
Ideas often wait until materials catch up, for example modern manufacturing makes precision components like an 8-speed derailleur widely and cheaply available.... The idea was not new, but needed manufacturing technology to catch up. Which is how I read Hope's role in bike disc brakes.
I like disc brakes on my bikes, I am a fan of the BB7, but then I am big and heavy as are my Disc Trucker and Big Dummy...... Each to their own and all that...... What's to disagree about?
TPO
) unearthed a rather extreme example which even put the presiding judge into a tizzy. An elderly motorist and his wife had been ambling along a minor road when without warning, clean out of the blue (literally), a horse crashed out of the heavens smack in front of him, terryfying his motor car and giving his wife kittens! 
)