I’m sure you’ll get down the mountain just fine on your wooden skis. There’s better stuff available, but use what you have.

The limit the limit on bicycle brake performance is available braking traction. Most any braking system will lock either wheel. On a 90 year old coaster brake I can lock the rear wheel.

Consulting old reference works from the 50s, 60s, and 70s all testing showed that bicycles would achieve braking force of 0.5g to 0.6g. For comparison a current production high end Porsche will get slightly over 1.0g. Ordinary sedans can get 0.7g to 0.8g. For the automotive tests we are talking about fully prepped vehicles on a skid pad with professional drivers. In ordinary usage autos do not achieve numbers that high and few drivers would attempt to reach braking that severe. For the bicycle braking tests it was most any available bike and most any available rider. Bike testing was not done with accelerometers, it was done by measuring stopping distances and working backwards, giving an average deceleration over the complete stop rather than an instantaneous measure. The notion that bikes have bad or weak brakes is nonsense. The notion that bikes do not belong in traffic because they don’t stop well is wrong.

Bicycle disc brakes are not more powerful than rim brakes. They do feel different. If you like the disc feel that is a good enough reason to use them. Claiming they are more powerful mostly means someone read and believed advertising.

If you want improved braking performance pay attention to braking traction. That means choosing tires suited for the surfaces you ride on. Pay attention to inflation pressure. Pay attention to your center of gravity and keep weight on both wheels. Stiff tires, over inflated tires, narrow tires will limit your ability to stop. These are all things that are up to the rider. Imagining you can solve problems by buying something rather than doing something will get you into trouble.

I agree with most of what you've said with some quibbles.

First, the limit on bicycle (well, any brake) performance is the available tire traction. If you overcome the available tire to road friction, the tire will slide.

You can lock the wheel on a coaster brake because braking transfers weight forward and unloads the rear wheel. With only a rear brake, you quickly lift the rear wheel to the point where it locks and starts to slide.

Mostly correct with one caveat. Bicycles are limited in the amount of deceleration that they can achieve by the friction on the front tire. Bicycles are completely unable to overcome the friction on the front wheel so that they can skid the front wheel. Before the front wheel can lock, the rider will be thrown over the bars.

I fully agree which is why I find disc brakes mostly irrelevant.

One thing missing is comparing wet/dirty rubber brake pads on a wet/dirty rim vs. dry/clean brake pads on a dry/clean rotor. Disc brakes excel at stopping in adverse conditions, which is when they are most needed. If you want real world comparisons, there is a link to a video posted earlier in this thread.

Good Lord. I provoked a discussion on technique as well as equipment. More than I could have hoped for.

As for going over the handlebars there is a good discussion on that in Whitt and Wilson, Bicycling Science(MIT,1982). Basically it will not and does not occur if your center of gravity is where it should be on a bicycle. Only way to make it happen is to be seated entirely wrong. Or to run into something. If you smack a high curb head on, or a log on the trail or something like that of course you go over.

Which brings me to something for the OP. What kind of touring are we doing? If it is kitchen sink touring with 50 or 100 pounds of impedimenta, just get a longtail. It will come with discs and there you are. Even when decelerating downhill there will be enough weight over the rear that you have two functional brakes instead of just the one. The extended wheelbase will give back a lot of the comfort that went away with a fork strong enough to survive a disc. Braking will be better because you are more stable. Long tails generally come with fairly wide tires. The big ones will brake better, keep the bike steadier, last longer, create more comfort. And when heavily laden they are probably faster than overloaded skinnies.

One more about bike parts. Mafac introduced their centerpull caliper brake in 1951. Versions of that brake are still being produced and sold by Paul Components, Compass, Grand Bois. 67 year old design and still goes on high end bikes. Now you could believe that this is only possible because well-heeled clients have fallen into a fiendish trap set by the bike industry to kill off the last adherents of the old and the unsafe. Or it could be they are some good brakes.

When the Mafac brake appeared in 1951 it completely changed road racing. Descents were immediately much faster. When discs got into the peloton what happened was, um, not much. In fact while first day of the TdF most bikes had discs, by week three you had to look hard to find them. Any possible advantage was more than offset by slow wheel changes and bikes that rode and handled badly. Discs are a game changer off-road. On the road the best thing about them is the bike biz gets to sell you a complete new bike. No way to retrofit these to a bike you already own.

63rickert is both right and wrong. I've endoed a number of times both on- and off-road, although on-road endos are rare. But one thing I do in all braking situations is to push back and down on the bicycle. It's a learned reflex and automatic and it has saved me from many more endos. It increases your deceleration which makes the stopping distance shorter and might prevent you from hitting that car. It won't prevent all accidents but it does help

Sorry but djb and Tourist in MSN aren't completely wrong. Anyone who bicycles should expect to crash once in a while. It's much more common off-road than on- but it is still an inevitability that can't be completely avoided. Tourist in MSN's experience is fairly common because we don't have complete control over everyone around us. I've been hit by a pedestrian, knocked off a bike by a fellow bicyclist who turned left instead of right, and been hit by a car that turned left in front of me. I couldn't have avoided any of those crashes, no matter how far back and down I got on the bicycle. Not even situational awareness would have prevent any of those accidents.

I've crashed more times than I can recall in all kinds of situations. Many of them are my own fault...pushing the envelope...but many of them are just events that happen that I have no control over. I've also avoided an infinite number of accidents more by being aware of the situation and knowing what to do to make the outcome better.

I’m an old guy. If I fall bones will break. Occasionally I ride with a couple of guys in their 80s. Falling is not on the program. Another ride companion has about 15% of normal bone mass. If he falls he probably dies. He can break ribs by sneezing. He’s also won some races recently. He hasn’t taken a fall for forty years. I’ve only gone twenty years. I ride every day.

Bikes are safe. Please be safe.

You’re over-romanticizing things here. Yeah, the Mafacs were a huge improvement over the earlier really crappy, crude brakes they had before. That’s the way it goes. The longer things are around and get more refined, the less drastic the improvements. I’ve also ridden Mafac Racers on a couple of vintage bikes I’ve owned and they’re totally decent brakes. I’ve ridden many newer brakes that were worse. That doesn’t mean we should all be riding around on Mafacs and the only reason we aren’t is because of the big bad bike companies trying to sell us new bikes. Of course the companies you list selling the old Mafacs are boutique companies who tend toward quirky and vintage-y componentry. Don’t get me wrong, I love a lot of the stuff they make, but pointing out that a retro car shop still makes brakes for my old 46 Ford doesn’t mean those brakes stop a car as well as modern ones and the car companies are trying to sell us crap we don’t need. As for the TDF, they use the Best rim brakes produced, paired with the Best housing, Best levers, set up by the Best mechanics, etc, and I’m Certain they work better than regular people’s brakes. Most importantly, as you said, disks make for slower wheel changes. That alone was probably reason enough. I do think they probably only had them in the first place because the big companies wanted them too. I’m sure they knew ahead of time that their rim brakes made for faster wheel changes, etc. They also aren’t riding in the kind of conditions a lot of us are, though.
I’m not worried about fast wheel changes. I’m not running a $1,000+ brake set-up. I’m concerned with low maintenance and poor condition performance(when I’m more likely to have an issue where I need them). I say this keeping in mind I see zero reason for disk brakes on my road “race” bike. I have Dura-Ace rim brakes on it with nice levers and high end cable. It only gets ridden on sunny days with not much weight on it(I’m ~150lbs). It stops great. I don’t ride it as much as my daily or MTB, so hardly ever have to maintenance it.
That said, I’ll never bother having a daily rider/touring bike without disk brakes again. I wouldn’t be upset if I did, and V-brakes do stop me fine, but disks do so a little better and with no maintenance.
I’m running tubeless these days too. I put on a new tire and new brake pads, put the wheel on the bike, and never think about either again until they wear out. I turn a little clicky knob once in a great while to adjust my BB7 brake when the lever gets near the bars. Takes two seconds. It’s nice not checking and adjusting brake pads or dealing with flats. It gives me a little more time to tinker with new project bikes or other interests.

I’ve actually never had much problem with them, but some folks seem to have issues with them scrubbing and stuff. I do find I have to take more time lining up the disk to get it into the caliper compared to just dropping in the rim braked wheel. And the fact that they’d all be using hudraulic brakes could be disaster in a quick change situation. Somehow the brake lever accidentally gets bumped while the wheel is out and suddenly you have a compressed caliper, and that wheel isn’t going back in...