Monday, December 17, 2007

My New Project (and a sobering personal aside)

I am fascinated by internal-geared rear hubs. I have been, ever since I took apart my best friend's brother's 3-speed rear hub when I was 11, and then couldn't put it back together. (Of course, the undersides of cars are very fascinating, too, so I didn't much mind having to dive for cover every time he came around. This was a survival skill in rough, scrapping West Albany.)

One of the things that saps my will to live in the winter is the amount of cleaning and maintenance required of conventional multigear drive trains -- what, with the exposed cassette and shifting mechanism, the coupled derailer and chain tensioner (a.k.a., "derailleur"), &c. And so I'm determined to get myself an internal-gear rear hub and build a bike around it. There are a few varieties, but Shimano makes a couple of 8-speed hubs, with drum and disc brake options.

One concern, however, is the range of gear ratios available. Although 8-speed hubs generally have around around 300% step-up in gear inches, it's still not quite as much as on a conventional multigear bike with a triple crank, and say, 12-26 cassette. And so I'm thinking of pairing the internal hub with a double crankset.

However, this leaves the question of how to take up the slack in the chain when it is on the smaller ring, which is the pretext for this thread I started in

Which brings me to the sobering personal aside. One of the respondents to the thread is Sheldon Brown. If you've searched for bike tech information on the web, you know that Sheldon is the bike mechanic in the U.S. He's tried virtually everything, and has documented it.

Anyway, in his responses, Sheldon mentions that he has multiple sclerosis, and it has progressed to the point that he can no longer ride a two-wheeler. I think that is unspeakably sad. And yet he carries on.


Nic Pottier said...

Ya, my heart really goes out to Sheldon. Even as vast as the internet is, he's one of the primary figures for anybody who rides a bicycle, that's no small thing.

I have to echo Mr Brown though Ted. What do you need all those extra gears for? Surely if I can get by riding around Seattle with one gear, you can do with eight!

I was pondering a similar setup for a commuter bike, but even taking a bit further. In addition to the internally geared hub, I'd use hub brakes, maybe even a dynamo front hub to power lights.

I think the ultimate would be to build such a bike with a steel frame, and then carefully route all the cables internally somehow. Looks like a fixie at first glance, but is totally functional.

Ted Diamond said...

It's not so much whether I can do it. I can live with the compromise of a 3x step-up, by having a low gear low enough to get me up the 17%+ grades I like to go up in West Seattle, and spinning more at the high end to keep up with auto traffic.

But I am interested in creating a bike that has the accessibility of multi-gear bikes, without the need for constant maintenance. My overarching goal is to study and promote technologies that make cycling as easy as possible, to get as many people as possible out on the road. And I suspect that for someone who is used to the wide range of ratios available on today's popular bikes, a 3x step-up would be an unacceptable compromise.

For instance, when I asked Carol whether I could spend $200 on her dream bike to replace her 52/39/30-12x26 Ultegra drivetrain with a drivetrain that weighs a lot more and gives her a narrower range of gears, but would be easier for me to maintain, she asked whether I could kindly go fuck myself. Vox populi