Dunlop, John Boyd (1840–1921), inventor, was prematurely born, 5 February 1840, on a farm near Dreghorn, Ayrshire, Scotland, son of John Dunlop and Agnes Dunlop (née Boyd). He was considered a delicate child, and instead of farmwork was allowed to continue studies at Irvine Academy; he graduated from the Royal (Dick) Veterinary College, Edinburgh, aged only 19. For eight years he worked in Edinburgh; then (1867) he established what became a very successful veterinary practice in Belfast. In October 1887, to protect his 9-year-old son from the jolting caused by the solid rubber tyres of his tricycle on the cobbled streets of Belfast, Dunlop improvised an air-filled rubber tube, held on to the wooden wheel by tacked-on linen cloth. It was soon found that Dunlop's tyres greatly improved performance, and local riders sought to acquire them; although to allow his tyre to be used, modifications to the frames of existing safety bicycles were necessary. He entered into arrangements with several Belfast businessmen, and registered a patent (December 1888) for an air-filled tube attached to the wheel by rubber cement; the patent was granted in July 1889. His Belfast partners, unable to produce enough bicycles, contacted a Dublin businessman, William Harvey du Cros (qv), who was himself a keen cyclist and whose son Arthur (qv) was Irish cycling champion. Du Cros enthusiastically assisted in floating the Pneumatic Tyre and Booth's Cycle Agency – as it was at first called – but demanded complete control. Dunlop received £300 for his patent and 3,000 shares in the company, but when it was discovered only ten months later (November 1890) that the patent was invalid because an earlier patent existed, Dunlop was disconsolate and would have abandoned the manufacture of tyres. He also patented a tyre valve, but he was neither particularly successful in further technical innovations, nor interested in the commercial and administrative activities required to develop his invention. Du Cros, on the other hand, resourceful and fiercely competitive, secured other patents, and the company became increasingly profitable as it manufactured cycle tyres, then motorcar tyres, and later other rubber products.
The Dunlop name and a picture of Dunlop himself were used as company trademarks, even after he resigned from the board (16 March 1895). His reasons for so doing were never made public; the difficulties over his patent may have contributed, but du Cros and Dunlop were perhaps too dissimilar to work well together. Dunlop lived in Ballsbridge, Dublin, from 1892, and was director of Todd Burns, the Dublin drapery firm. Despite his lifelong valetudinarianism, he was 81 when he died in Dublin (23 October 1921). He married (1876) Margaret Stevenson from Ballymena, Co. Antrim. Their only son died in 1920; they also had a daughter.