Mind that Bike is the twenty-sixth episode ever made in Season 4.
Tom Tipper the postman is ill and when he returns, he finds his van has been replaced by a bicycle due to maintenance costs. Tom is later called away, and he carelessly props his bike against Percy's mail vans. Percy's driver does not realise and, as Percy starts, the bike falls onto the line and is crushed. Tom is dismayed, but when the postmaster finds out, Tom is given a new van, to his delight.
- After Percy crushes the bike, there's a shot of his cab, judging by the amount of space and the shape of the windows, it's really Duck's cab.