Eurobike: Tune uses magnets in new hub
By James Huang, Technical editor | Friday, September 18, 2009 6.25pm
The wavy aluminium spacer contains an array of magnets that are repelled by another set of magnets in the hub shell to push the steel ratchet ring against the freehub body. Tune's new driver design uses just one moving part. James Huang
German lightweight specialist Tune has adopted a unique approach to its latest series of ultralight hubs, using a pair of opposing ratchet rings similar to DT Swiss and Chris King drivers.
Instead of using conventional metal springs to push the faces together, Tune's design uses two arrays of magnets with like poles oriented towards each other.
One set of magnets is mounted in the hub shell and the other is housed within a wave-shaped aluminium ring, which then pushes a thin steel ratchet ring out towards the aluminium freehub body. Rather than use another separate driver ring, though, Tune machines the mating ratchet teeth right into the freehub body to save weight.
The 96g Tune Mag 90 rear hub
And save weight it does: the new disc-compatible Dezibel rear hub reportedly weighs just 150g while the road-specific Mag 90 version barely tips the scales at 96g. In addition, Tune claims the new design is more durable than conventional setups, too, as there is only one moving part and no metal springs to wear out or break.
Cannondale Lefty users get their own new machined aluminium hub design as well called Cannonball. The standard version weighs just 99g while an ultralight SL version with carbon-wrapped flanges drops another 10g. Both incorporate built-in pullers, too, to more easily remove the wheels from the axle stubs.
Need more? Tune has also developed a new Big Foot machined aluminium crankset complete with an SRM wireless power meter, a 30g pair of carbon fibre bar ends is in development, there's the 79g Capy machined aluminium integrated seatmast head, and long-time Tune devotees can even jump on the company's limited edition 20th anniversary component group with special laser-etched graphics.
Now how do you say 'light makes right' in German?
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