Why does it need to be one or the other? Steel or CF.
I ride steel (old & new), CF, Ti - and previously Al.
imo, a better Question would be:
Why do you ride just one or two bikes?
or
Given the affordability of vintage bikes, why don’t you ride at least 4 of them? Reynolds, Columbus, Tange, Ishiwata tubing.
You can become a better cyclist faster by riding your bike rather than fixating on the frame material. No nostalgia required.
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Vintage, modern, e-road. It is a big cycling universe.