Brunel student creates missing link for cyclists

Chris Holloway, who graduates from Brunel University, west London, this summer, won the Xerox Innovation Award for designing a safer system for gear changing downhill, a well-known problem among cyclists.

’While every other part of the modern mountain bike has changed to meet the modern demands of downhill racing, the gear system has barely changed for more than 100 years. For the pinnacle of the sport, it is clear that a better alternative had to be found,’ Holloway said.

Holloway’s design came about from his personal experience in downhill racing, both as a rider and a spectator. His ’Link’ gear system is an expanding chain ring gear system that can replace the old chain-and-sprocket system.

Essentially, the four segments in it expand and contract to give three different gear ratio sizes. An important design feature is that each segment moves out independently, and this is what makes it capable of being used with a chain and not just a smooth drive belt.

The young designer told The Engineer that the advantages of the new design included seamless shifting, higher efficiency, longer chain and sprocket life, as well as improved weight distribution.

’On full suspension bikes, it is important to minimise unsprung weight to obtain the maximum performance. By removing the rear derailleur and cassette, the mass is relocated between the riders feet and away from the suspension, which gives much better small bump response, as well as increased grip and cornering ability,’ Holloway said.

As the system is designed to fit around a standard four-bolt mountain bike crankset and standard BB mounting, the advantages of the new system can be obtained on almost any modern DH bike or frame.