Before WW2 most bike manufacturing was done through small business which would hand craft bicycle to your specification. During WW2 bikes became an important part in the way britain traveled as fuel was rashioned and cars were expensive. The bike also became a crucial tool that the army used for easy transport within the uk and abroad. Factories were then set up to mass produce bikes for the mass use that at the time was intended. After the war the bicycle was still the most affordable form of transport and brands such as raleigh and claud butler were born out of the factories that created army goods as well and the army bicycles them selves.
The industry continued to grow in the uk until the 1980s this is where bike manufacturing became much more specialized and only small brands could afford to make bikes in the uk and USA. By the 1990s carbon fibre had been introduced into bike manufacturing and 90% of bike manufacturing was being done in asia specifically mostly in taiwan.
Skip 20 years and this was still the case the bike industry now being worth 37.5 billion euro and growing by upto 8% per year. In 2012 a cycling boom happened and the uk went mad for cycling after the london 2012 olympics. this created room for high end brands to push the boat out and create expensive limited number bike production of 250 in a batch. this bikes reaching upto £12,500. But people wanted more something that is there own. with in all the manic cycling boom small frame builders opened back up or started up compelely to create one off bikes for people to have as their own hand crafted pieces of art.
http://www.cyclelicio.us/2011/bicycle-lockheed-ww2/
http://www.bikeradar.com/gear/article/military-bicycles-a-short-history-34906/
https://critiqueofcrisistheory.wordpress.com/the-five-industrial-cycles-since-1945/
http://classiccycleus.com/home/repair/bikes/
http://www.economist.com/node/21552898
http://www.ellisbriggscycles.co.uk/history/
https://en.m.wikipedia.org/wiki/History_of_the_bicycle (used links off this get other information)
https://www.google.co.uk/amp/www.cnbc.com/amp/id/44857810?client=safari
https://www.kennedycitybicycles.cc/#an-urban-bicycle-manufacturer
http://www.independent.co.uk/extras/indybest/outdoor-activity/cycling?amp=
L5 SFC4 Josh Brooks 