Originally Posted by
unterhausen
50 years ago was 1972, the biggest differences are that in 1972 the bikes had better paint jobs. And the riders actually used their drops a lot of the time.
Wheelbases were a little longer, the chain stays were a little longer, the fork rakes were a little different and the fork crown was not so close to the front tire. You could fit more tire. The biggest difference for me at least are the seat tube angles of modern carbon frames, they are steeper than the old steel frames and comfortable setback is a challenge. Measure an old Merckx or Masi GC. These old steel racing frames are what I would call a Century geometry or even super touring geometry compared to the geometries of carbon frames that followed, which ostensibly due to the cost of molds, most Mfgs do not offer as many sizes and the back half triangle is the same on all sizes. And if you are a big rider, you can pick a 58 or jump up to a 61. It is only recently that racing bikes could fit 28 mm tires whereas many (most??) 40-50 year old steel frames can easily take 28 mm tires.
Drops are not the fastest position anymore with flat top and narrowed bars. The cross sectional area of the leading edge of the drop isn't even round on many carbon bars. 36 or 38 mm width are very common. I am using a flat aero topped carbon bar with a suspension stem for comfort and it makes a world of difference. The transition from the brake hoods to the bar is nice flat spot to park your hand and the flexible bars take a lot of road buzz away while the stem elastomer helps on larger hits. The hand discomfort is why a Mtb bike and also moustache bars did not work for me, they are fine for shorter rides and riding 100km into a wind sitting upright was all I needed to know that a road bike was better for me. A stronger rider might not care about an hour or two lost to the wind.