Before the Second World War cigarette manufacturers had invented the idea of the collectable card. Cigarette packs needed a small piece of cardboard to stiffen them, and manufacturers hit upon the idea of printing these as collectable sets on various themes. Children became addicted to collecting them and pestered their parents to buy more tabs of that particular brand. 'Pester power' had been born. However cigarette cards disappeared during the War and never reappeared.

In 1954, with the end of tea rationing in the UK, Brooke Bond, a major UK tea brand, teamed up with the Daily Mail newspaper to reintroduce the idea. Brooke Bond put small cards into its packs of tea. In the late 1950s Brooke Bond took-over the Priory Tea Company and introduced Priory Tea I-Spy cards, in association with the News Chronicle (a newpaper title owned by the Daily Mail group).

I believe that the Priory Tea I-Spy series relating to bicycles were produced in 1959 or 1960. The News Chronicle ceased publication in October 1960.

Companies House baldly states that the Priory Tea and Coffee Company was incorporated in 1932 and finally dissolved in 2013.