The basic road bike hasn't changed all that much in the last few decades. Putting it another way, the basic mechanical design was nearly perfect even when I was a toddler (when dinosaurs roamed the earth).
Take my commuting bike (please). It is a Falcon. Actually more like a Phoenix, a Falcon frame that I got used from a friend in NEBC and built up with parts I had laying around. I gather it is an English frame of '70s vintage. Its former owner raced it, but now it's relegated to the five o'clock 500. I think it has passed from the merely old to the collector's item category by now, or would have had I taken care of it. The frame is Reynolds 531. Now I know Reynolds is up to much higher numbers by now (more is better), not to mention titanium, aluminum, carbon fiber, but it's still a very nice frame, what's left of it after the paint was replaced by rust. Except for a few modern tweaks, it's basically the same bike today as it was when Woodstock happened.
Since those days, there are several really great inventions that changed cycling completely. And some not so great.
The Good - I know most of you can't conceive of a world without index shifting, just like I find it hard to remember life without the internet, but, yes, there was a time when you shifted by pushing that little lever a bit, then a bit more, then clunk it would plop into the next gear. Usually, you had to push it beyond the stop to make it shift, then back so that it wouldn't grind. Being that shifting is basically a digital operation, the need for a device that automatically put you where you needed to go was obvious. Of course, troglodyte that I am, I resisted these new fangled things for a few years on the erroneous basis of reliability.
One relatively minor change was concealed brake cables. You can always tell an old movie about cycling like "Breaking Away" or "A Sunday in Hell" by the brake cables sticking straight up out of the levers. No great improvement in functionality, in fact it could be argued that making the cables take a more twisty path actually reduced their life, but they sure make the bike look a lot nicer.
The real biggie of course was integrated shifting. I usually refer to this as STI, which is of course a Shimano brand name (sort of like Kleenex), and I've heard the term brifters (brakes+shifters), but you get the idea. No more reaching down for those levers on the down tube, your hands are on the brakes, and with a quick flick of the wrist, a shift. I heard the usual litany of objections when they came out, "What happens if they get out of adjustment?" (you take a cab), so I didn't jump on the bandwagon right away, but when I finally bought a new bike around Y2K that had them, there was no going back. Of course, I still have the old stuff on my commuter, which is a basically a disposable bike, but on weekends, I want my STI.
The Bad - The quintessential example of a Really Bad Idea was Biopace. This one sounded good on paper and it made all the engineer types salivate. The idea was that the force you exert at various parts of the pedal stroke was unequal, so why not make the chainrings elliptical in an attempt to even things out. Seemed like a good idea, and for a season or two the hills were alive with the sound of Biopace. The Biopace bubble burst shortly thereafter, and the only plus for me was that I could get a whole lot of used Biopace chainrings really cheap.
Fast forward to the 21st century. The belt drive. This sounds like a great idea, no more nasty chain to rust and collect grease. Only minor drawback is that you have to throw away your derailer (remember, the best invention in the bike world since round wheels). I can hear the fixed gear types saying "what's the problem?" but for the other 99.99% of the cycling population, this can indeed be a problem.
The jury is still out on hydraulic disk brakes. Not the disk brake part, the hydraulic part. For me, this is mostly flashback to my old TR3, where I had to pump the clutch several times to compensate for the air that had crept into the hydraulic lines. Maybe my fears are unfounded.
Then there's electronic shifting. Another assault on my old friend, the cable. First, the reliability question rears its ugly head. If the batteries on my TV remote crap out, I just go downstairs and replace them (or, heaven forbid, get up and change the channel manually), but if I'm on the road and the shifter batteries go south, well, good news for the cab company. I'd be willing to give it a whirl, if the things didn't cost more than most of my bicycles. I'm a classic late adopter, so I figure when these things get down to a reasonable cost, I might sign on.
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