This is a deluxe, quality, price list in every detail, designed to convince the cycling world that the new professional Simplex Criterium derailleur was a ‘deluxe quality product in every detail’ - not the flimsy, mass-produced, plastic, gewgaw that many privately suspected.

So deluxe was the Simplex Criterium that it was fitted to Tom Simpson’s Tour de France bike (see page 1). However, despite its claimed quality, page 2 gives the Simplex Criterium’s price as 67/6 (£3.38 to you). The Bank of England’s handy inflation calculator indicates that this is the equivalent of only £51.66 in 2011, making the the Simplex Criterium spectacularly affordable - comparable in cost to a Shimano 105.

One alarming item is the ‘security stop’ shown on page 6. It seems that Simplex did not trust the adjustment screws to do the job of keeping the derailleur out of the spokes - and anyone who worked in a bike shop at the time knows why. The Delrin parallelogram was simply too flexible.

• Publisher: Simplex
• Country: France, although this price list was produced in the UK
• Date: 1966
• Derailleur brands: Simplex
• Derailleurs: Simplex Prestige (537), Simplex Criterium