Why is drum to disc called an upgrade?

[dmjlambert]

Interesting discussion so far. Stories are interesting. I was kind of hoping at some point there may be more than anecdotal evidence about the differences. I buy that there is actual science and proof that ABS is better than no ABS. I suppose ABS drum system would be quite good, if there was such a thing. With ABS you are talking about adding a control system that does something a human can't do with his foot, and not simply changing the orientation of friction surfaces.

The anecdotes about disc vs. drum are more plentiful than actual scientific studies it seems. The drum shoes contact a greater surface area than the average little pads of disc brakes, and that is made up for by the fact that disc takes more pressure to give the same amount of friction. In the end the same thing is achieved. Much comparison is done about old broken down and improperly maintained drum brakes that were finally "upgraded" to disc and now wow does it stop great. I guess I would expect that to be the case. The real significant upgrade is the fact that it's newer brakes.

I'm convinced drum to disc may be a small upgrade because of
1. maintenance, and
2. performance because the installed system is newer, and
3. the disc will wipe dry faster than a drum will drain if it gets under water, and
4. fade is a factor if that applies to your situation, and
5. the focus of current reproduction industry on disc brakes, because they are much less expensive than drum and more popular, leads to more readily available whole new systems that are disc. A whole new drum system would not be found any more, and some drum brake parts are not available. So, availability is a factor also, especially if a whole refresh is needed. And who doesn't need a whole system refresh on a 49 year old rust bucket like mine?

The much bigger upgrade would be from drum or disc to some sort of ABS.