I can believe that an MB1 is a very light bicycle as my 1990 Moulden XC mountain bike (rigid) weighs 23 pounds with a 24 speed drivetrain... the only real difference between it and the Ron Cooper is the extra weight in the mtb tyres which are 800 grams heavier than the road tyres on the Cooper.

On cranks... the Stronglight on my Garlatti and Sugino Competition on my Cooper are as light as most modern high performance cranks that do not utilize carbon fibre and even then, they are very close.

In their day they were among the lightest cranks money could buy.