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- Da Bomb Bikes - USA/Taiwan
- Dahon - USA / China
- Dawes Cycles - UK
- Demorest - USA (restructured as Lycoming Foundry and Machine Company and discontinued bicycle manufacturing)
- Den Beste Sykkel Better known as DBS - Norway
- Derby Cycle - Germany, owns Kalkhoff, Focus, Nishiki, Rixe, Raleigh and Univega
- De Rosa - Italy
- Cycles Devinci - Canada
- Di Blasi Industriale - Italy
- Diamant - Germany, owned by Trek
- Diamondback Bicycles - US
- Dorel Industries - Canada, owns Pacific Cycle and markets under brand names including Cannondale, Iron Horse, Schwinn, Mongoose, Roadmaster, and GT.
- Dunelt - UK (defunct)
- Dynacraft - USA, owns Magna and Next
Read more about this topic: List Of Bicycle Brands And Manufacturing Companies