Caterham worked with British bicycle tube-maker Reynolds Technology and a computer-aided engineering firm to create what they claim is the world's first automotive space frame that uses butted tubing. In this method, each tube has thicker walls on the ends but is thinner in the middle. The result is that some of the chassis parts are up to 50 percent lighter, but the whole structure maintains the torsional stiffness of the traditional production methods.
The downside to this lightweight innovation is the cost. Caterham estimates a butted tube construction option would add $1,440 to $2,880 to a Seven's cost. The automaker doesn't estimate when a production version might be ready, but keep an eye out for the lighter construction method on its vehicles.
Reynolds developed new tooling and processes to make the butted tubes work for this application, and according to Caterham, the methods would help shave weight off any spaceframe.
A trio of British companies has produced the world's first car chassis using butted tubing technology taken from bicycle production.
Famous bicycle tube-makers Reynolds Technology, high-quality Computer Aided Engineering (CAE) consultancy Simpact and sportscar maker Caterham Cars shaved more than 10% off the weight of the already lightweight chassis of the iconic Caterham Seven.
The research and development project unveiled a prototype Seven using the new technology and processes at the Niche Vehicle Network Symposium on Wednesday, March 16.
Caterham believes that an ultra-lightweight Seven using the new technology would cost between £1,000 and £2,000 as an option on the standard vehicle but could be taken up by as much as a fifth of future Caterham customers.
Reynolds, which first patented the process for making butted tubes in 1897, provided the tubing technology for the initiative and had to develop new tooling and processes. Meanwhile, Simpact Engineering conducted the virtual analysis and testing to derive the specification and positioning of butted tubing and Caterham built the first prototype car.
Butted tubes are thicker at the ends than in the middle, meaning that frames can be both strong and lightweight. By using low-cost mild steel rather than more 'exotic' alloys, the project made large mass reductions of up to 50% on some parts without losing any of the chassis' torsional stiffness or strength.
Simon Lambert, CTO of Caterham Cars, said: "Caterham has made its name as a purveyor of lightweight sportscars but we believe more can always be done to reduce weight and, therefore, emissions.
"Caterham and Reynolds are two proudly British brands and there is a real synergy between customers of Caterham and cycling enthusiasts, so it's even better that the technology that has made this possible has come from the two-wheeled world."
Tim Williams, director of SImpact Engineering, said: "The CAE models built and developed by Simpact provided a rapid and accurate assessment of design investigations and proved to be the only practical way to deliver the lightweight design in such a short period of time."
Keith Noronha, Reynolds MD, said: "We have had to expand our capabilities to meet the technical challenges seen during the course of this collaborative project, and are delighted to see specifically-engineered butted tube now in use on the iconic Caterham Seven."
Caterham will continue to develop the existing prototype vehicle, with a view to launching a production version in due course. The research and processes can also be adopted by other companies using spaceframes.
Grant support for the engineering and development project was provided by the Niche Vehicle Network, which offers innovation support to the UK's vibrant niche and specialist vehicle manufacturing sector. The Network's activities are funded by Innovate UK - the UK's innovation agency, the Office for Low Emission Vehicles (OLEV) and the Department for Business Innovation and Skills.
Please visit http://www.caterham.co.uk or call 01293 312300 for more information.