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The featherbed frame was a motorcycle frame developed by the British Norton motorcycle company to improve the performance of their racing motorcycles around the twisting and demanding Isle of Man TT course in 1950. It was considered revolutionary at the time,〔Motorcycle handling and chassis design: the art and science by Tony Foale. 2006〕 and the best handling frame that a racer could have.〔The Café Racer Phenomenon by A Walker. 2009〕 Later adopted for Norton production motorcycles, it was also widely used by builders of custom hybrids such as the Triton, becoming legendary and remaining influential to this day.〔 The Featherbed inspired other frame builders who based their own products on similar principles, including the heavyweight Münch Mammoth and a lightweight version for a 250 cc BSA C15 engine.〔''Motor Cycle'', 3 February 1966, pp.142-143 ''On the Four Winds'' by 'Nitor'. Accessed and added 2014-09-28〕〔''Motor Cycle'', 24 November 1963, pp.696-699 ''All the rage'' by ''John Ebrell. " ...Ilford's CeeR-Speedshop. For £29 they'll supply the C15 rider with a featherbed-type duplex frame''". Accessed and added 2014-09-28〕 The Featherbed was replaced by the Norton Isolastic frame in 1967 for the then newly-developed Norton Commando which used a rubber-mounted engine and gearbox,〔Norton By Mick Woollett. 2004.〕 although Norton continued to offer the ''Mercury'' with a Featherbed frame until production ceased by 1970. Replicas of the frame continue to be produced by specialist companies.〔(Andover Norton Frames and Auxiliaries made to factory drawings ) Retrieved 2014-09-28〕〔 ==Origins== In 1949 brothers Rex and Cromie McCandless offered Norton a new frame to support their successful 500cc race single. Rex McCandless was a self-taught Belfast motorcycle engineer and raced competitively with his brother on a Triumph Tiger 100. He had made several improvements to the Triumph, notably an innovative new frame with a swinging arm fitted with vertical hydraulic shock absorbers from a Citroen car. BSA bought several of his converted motorcycles but Norton saw the real opportunity and contracted him to work exclusively for them from 1949. The Norton Motorcycle Company were concerned at the reliability of their plunger (or "Garden Gate") frame, as several had broken through the stress of racing. Norton engineer Joe Craig solved the problems by making the frames heavier but handling suffered as a consequence.〔 Norton commissioned the McCandless brothers to design a complete frame, incorporating a swinging arm. McCandless' finished design was expensive, as it required over forty feet of the best Reynolds steel tubing. It was a welded twin loop with a swinging arm fitted with their own design of shock absorbers, with a heavily braced cross-over headstock. In two months a prototype motorcycle with the new frame was on the test track and it was tested on the Isle of Man in the winter of 1949. It performed well and Norton decided that the Norton works team would have motorcycles with the new frames. The Norton works was not well equipped so the sif-bronze welding was undertaken by the McCandless brothers who produced the eight frames for the racing team by hand. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Featherbed frame」の詳細全文を読む スポンサード リンク
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