From Graces Guide
Kirkpatrick MacMillan (1812-1878) was an early pioneer of the bicycle in around 1840
Kirkpatrick Macmillan (Born 2 September 1812 in Keir, Dumfries and Galloway; Died 26 January 1878 in Keir) was a Scottish blacksmith who was given credit for inventing the rear-wheel driven bicycle in a publicity campaign by a relative, a rich corn trader and tricyclist named James Johnston in the 1890s. MacMillan lived in Glasgow and worked at the Vulcan Foundry during the relevant period around 1840, not at the family smithy Courthill.
Johnston's articles stated that he completed construction of a pedal driven bicycle of wood in 1839, and that it had iron-rimmed wooden wheels, a steerable 30 inch (760 mm) wheel in the front and a 40 inch (1016 mm) wheel in the rear which was connected to pedals via connecting rods. The entire machine weighed 57 lb (26 kg). Johnston connected him with a Glasgow Newspaper clip of 1842 that a gentleman was fined 5 shillings for speeding (8 mph or 13 km/h) and knocking down a girl who ran into the road. Johnston did not mention this part of the clip: "it moved on wheels turned by the hand by means of a crank." Thus the report of this accident does not specify that the vehicle had 2 wheels, a fact which would have been noteworthy at the time. Moreover Alastair Dodds observes that it seems unlikely that an artisan would be described as a gentleman at that time. Villagers allegedly thought him mad for dreaming up the first velocipede and called him 'Daft Pate'. The later founders of the bicycle industry did not indicate awareness of his work.
While MacMillan certainly existed and rode some velocipede, he didn't ride the velocipedes published by Thomas McCall twenty years later in 1869, as all rear-wheel driven velocipedes were a reaction to the Michaux velocipede. The copies on exhibit e.g. at the London Science Museum, London are all McCall's velocipedes, also the one at the Glasgow Museum of Transport, purported to be the original.
According to bicycle historian David Herlihy, there is no contemporary documentary evidence that a pedal-crank design was applied to a 2-wheeled vehicle; in addition, letters from customers in Scotland to the Michaux company in 1868 state that all of the human-powered vehicles there are tricycles and quadricycles. All of this casts doubts on the authenticity of claims made for Macmillan's priority in bicycle design. Besides Herlihy's book there is a short introdutction in David Gordon Wilson's Bicycling Science, 3rd edition.
The first man to fit pedals to a bicycle was Kirkpatrick MacMillan, a blacksmith of Courthill, Kier, Dumfriesshire, in 1839 or 1840. On June 8th, 1842, he was fined 5/- at Gorbals Police Court, Glasgow, for riding on the footpath and knocking down a child. MacMillan drove his rear wheel by cranks and swinging levers, and steered his front wheel by direct sloping forks. No doubt he started and gathered speed by the old Hobbyhorse method, and did not pedal till his machine was travelling at a fair rate.
Sources of Information
-  Wikipedia