Yes the bike is made of Raleigh 2030 carbon steel, but what matters more is the gauge and butting of the steel used, not the carbon (or chromoly) content of the steel. In the late 50's through the early 1970's it was common to make "club racers" out of thin-walled 2030 carbon steel. Yes, the frame would be a little bit more flexible than a reynolds frame of exactly the same gauge, but the butting and thin tubing walls would give the bike a lively reynolds-like feel, with just slightly heavier tubes that weighed a few (maybe 4-8) ounces more than a reynolds 531 frameset.
In my experience, the double-butting in the forks and main triangle are responsible for the lightness and lively feel of high-end bikes. The alloys used to increase the tubing strength and lighten the frame are a 2nd-order optimization compared to double butting.
I had a double butted tange steel frame on my SEKAI 2500, 25 lbs with a very lively ride. There was no indication that it was chromoly tubing - the decal just said 'Tange Double Butted Steel'. By replacing some midrange japanese components on that bike (bottom bracket, crank, freewheel, rims, etc.) I could easily have dropped that bike down to 23 lbs.
Club Racers came to an end with the introduction of CPSC crash-test regulations in 1977-78. These regulations made club racers impossible to sell in the USA market. Low-end bicycle immediately increased in weight due to these regulations.
If it's a club racer, then the campagnolo gran sport derailleur (350? 400? grams) is the most likely reason that the bike might accelerate like a boat anchor ...
- Don Gillies
San Diego, CA, USA