Brunel student creates missing link for cyclists
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A final-year industrial design student from Brunel University has won an award for inventing a new gear system, called Link, for downhill mountain bikes.
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.
The Link gear system designed by student Chris Holloway has been patented by Brunel University
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Readers' comments (31)
Anonymous | 15 Jul 2010 5:03 pm
SO proud of Mr Holloway, clearly a genius...
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Gavin | 16 Jul 2010 1:43 pm
Looks a very interesting design. Has a prototype has been tested yet to prove the concept?
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Anonymous | 16 Jul 2010 2:09 pm
Looks like a neat solution, I would certainly be interested. Have these comments: Force at the shifter has to be low enough to enable gear change under full power. If you have to stop pedaling it won't be very popular.
Should stand up to a lot of abuse and contamination and still perform as above
Use deeper teeth.
This could well be the "next big thing" very impressive.
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Stephen | 16 Jul 2010 2:12 pm
Ditto,
Any trials yet? Speaking as a cyclist and working at a high tech test lab I'd love to hear more!
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Anonymous | 16 Jul 2010 2:37 pm
Can't mountain bikers cycle UPHILL.
The poor wimps. They need to develop a few muscles
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Editor's comments | 16 Jul 2010 2:37 pm
Do you ride a road bike by any chance?
bigyinn | 16 Jul 2010 3:02 pm
@ anon 2.37pm
Read the article, its for DOWNHILL bikes dummy!
Looks like it has potential, but not sure about the gaps...
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Holzfeller | 16 Jul 2010 3:14 pm
Given a hill and a bike, it is only sensible and logical to want to cycle downhill, not uphill. Nice design. Like a lot of clever things, it seems obvious. I'll be interested to see how it works, by design and in practice.
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Epicyclo | 16 Jul 2010 3:25 pm
This system has been "invented" several times since the 1890s.
I have a Cambiogear which is the same thing.
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P Salvagione | 16 Jul 2010 7:42 pm
From 1902, http://tinyurl.com/2fy3ytf and more recently 1990, http://tinyurl.com/24m8yhc.
Just a few minutes on Google Patents will elucidate the collection of solutions that anticipate Mr Holloway's invention.
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Anonymous | 16 Jul 2010 9:04 pm
There's reasons why this is targeted at downhill racers.
The radially moving segments probably can't shift under load, and also probably can't handle or shift under high torque (ie, standing on the pedals going uphill). Also, the sprocket is not round, so it's not going to be efficient enough for most racing applications. The range of gear ratios is also limited because the further you get from the ideal round sprocket (smaller or bigger), the less round it gets.
I aggree with Epicyclo - there are lots of radially expanding segmented pulleys in the patent database for over a hundred years - they even have their own sub-category. Nothing too new here.
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