BMW's Vision DC Roadster concept showcases future carbon frame tech
Carbon fibre might have been around for decades but it’s still something of a wonder material when it comes to combining strength and low weight and, after several false starts, it’s finally becoming widely accepted as a structural solution in MotoGP and for high-end road bikes.
Although cosmetic carbon bodywork has been the norm for both racing and posing over the last 25 years or so, efforts to use it in bike frames have been sporadic and met mixed success.
Big thinkers with small budgets have made it work; John Britten’s V1000 and the old Armstrong 250 campaigned by Niall Mackenzie spring to mind. But unsuccessful bigger efforts like Ducati’s 2009 Desmosedici GP9 have tarnished carbon’s reputation.
Recently, though, we’ve seen a spate of GP machines with carbon swingarms and frame sections, and ‘ultra-bikes’ like the Ducati 1299 Superleggera and BMW HP4 Race have brought the technology to well-heeled customers.
The next leap must be to bring carbon frames to the masses, and on that front BMW are in a strong position. As well as experience with the HP4 Race the firm have unrivalled know-how in mass-manufacture of carbon components, as seen on their i3 and i8 electric cars and even the luxury 7-Series.
The firm subtly revealed the way they’re likely to create mass-produced carbon bike frames when they unveiled the electric Vision DC Roadster back in June. While that futuristic electric concept drew attention with its ‘boxer’ style design and electric power, it also gave us first sight of a new type of carbon chassis construction that BMW patented several years ago.
The idea is to use carbon fibre tubes, manufactured using ‘pultrustion’ where carbon strands and resin are drawn through a heated die, creating an endless length of rod or tube.
That can then be cut to length and joined together with corner pieces, or ‘nodes’, made either of aluminium – as on the Vision DC – or chunks of ‘BMC’ carbon fibre made using a process called Bulk Moulding, where short strands of carbon are mixed with resin and moulded rather like plastic.
The result looks like a conventional trellis frame – of the type long favoured by BMW for their boxer-engined R-series models – but can be far stronger and lighter than a steel or aluminium equivalent.
The trellis-style design seen here is likely to emerge first on a high-spec boxer-engined bike, and perhaps it’s no coincidence that BMW have recently filed trademark applications for an ‘M1300GS’ – a machine that can only be an exotic future derivative of the R1250GS...