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Old 05-01-12, 07:30 AM
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Dawes-man
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Location: Tokyo, Japan
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Torpedo Automatic Hub Gearing Question

It is no longer possible to ride track bikes in Japan with just a front brake, as has been common in the UK for more than 70 years, due to brakeless riders killing and maiming people. The police have started issuing $625 fines to riders without front & rear brakes. As a consequence, I've had to think about what to do with my 2009 Chesini Pista. I didn't want to drill a hole in the rear bridge or hide it with an alloy sandwich so I've fitted an old Fichtel Sachs Torpedo Automatic hub with a coaster-hub. It's a shame... but there you are.

I finally found a nice 28h rim, a Mavic GP 4, without paying the earth, and also finally got round to building my first ever wheel (hurrah!!) with one eye very firmly on Jobst Brandt's excellent manual, The Bicycle Wheel. I've been riding the bike with the hub for 4 days now and while very different from riding fixed wheel it is still a lot of fun.

The thing is, with a 50T chain wheel and an 18T cog it's rather heavy. In low gear I think it's the same as it was fixed, with the same gear combination, but in high gear, which it slips into very smoothly once you get your speed up, it's hugely big. It makes me feel rather manly actually However, I would like to lower the gearing but I'm wondering how that will effect the point at which it will slip into the higher gear. In other words, will the hub slip into high gear at the same bicycle-speed as now? Or by fitting a bigger cog will the hub go into high gear at a lower bicycle-speed?

You can maybe tell that I'm clueless...

Here's the bike with the new rear wheel - don't want y'all complainin' now...

[IMG] Untitled by Dawes-man, on Flickr[/IMG]

[IMG] Untitled by Dawes-man, on Flickr[/IMG]

[IMG] Untitled by Dawes-man, on Flickr[/IMG]

Last edited by Dawes-man; 05-01-12 at 07:33 AM.
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