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.

[davepl]

Here'a a non-BS anecdote, but it was from my 69 B-Body, not my truck. It was four wheel drum and eventually became four wheel Wilwood disc.

Best stop I ever made in all drum was a dog ran out in front of me on a highway. I flatspotted tires and wound up sideways but stopped.

By comparison, 20 years later and same car with discs, the throttle stock open and I had to pile on the brakes. Not only did it bring the car down in speed as turned the key off, they allowed me to completely stop straight and true in my lane with the steering column locked (turned the key one step too far back in my panic!).

So I've lived with the same car both with and without, and while I limit my enthusiasm to stock GM setup, I really do prefer the disc.

Keep the speeds down (like WAY down in town) and drums are OK.

[saxart]

I think a lot of this discussion has to do with where and how you drive your vehicle. Where I live the traffic is relatively thin, and the roads are flat and straight. I also don't do much towing with my truck, so for me, drum brakes are fine.

If I lived in hilly (mountainous) terrain or towed much, there would be no debate. I'd put disks on in a heartbeat.

[dmjlambert]

How many of the C10s from 1971-72 had front disc brakes and no booster, just plain manual brakes? Was it 50%, 25%, 0%?

[Steeveedee]

Don't remember with trucks, but the dealership I worked at when the '71s came out had ONE Chevelle with manual disc/drum brakes, out of several hundred cars.

[dmjlambert]

I am wondering because I drove my Dad's 1974 C10 and it had manual steering and it was a base model. I am pretty sure it had manual brakes, but I don't remember looking, don't remember exactly how they felt, it's been many years and the truck's long gone. I don't even remember it has having disc brakes, but I guess it had to have them if that was standard back then. What years were disc brakes offered as an option, and what years were they standard? I really prefer manual brakes.

[cornerstone]

Originally Posted by dmjlambert

I was kind of hoping at some point there may be more than anecdotal evidence about the differences.

The anecdotes about disc vs. drum are more plentiful than actual scientific studies it seems.

Have you seen this? I believe it will make you appreciate why its called an upgrade.
https://www.youtube.com/watch?v=z-px...ature=youtu.be

[dmjlambert]

It just says video unavailable.

[dmjlambert]

I think I made a mistake asking a different question on this thread. I will start a separate thread about the brake boosters.