In maybe 1975, I was given a brand-new Schwinn-style (but not exactly a Schwinn) bike with a Bendix 2-speed hub. My mother had an older Schwinn Hollywood with a similar hub, hers geared a little lower. The old fella who sold new bikes out of his garage told us I got "one of the last 10 2-speeds made in this country." Probably hot air. But I believed this -- at least until I saw just now that 2-speed hubs are now available brand new. When did they start coming out? (Been 20 years since I was a bike mechanic.)
And one more question: I've always thought a two-speed would be perfect in a flat city like Chicago, where I live. But thinking that the only such hubs were Bendix coaster-brake relics like the one in my basement, I doubted if I could mount that hub on a lightweight messenger-style frame and operate it vigorously without bending the left chainstay from the torque. Could you do that?
It's moot, because I'd rather have a hand-brakes on such a bike anyway. But let's say someone did want a coaster-brake 2-speed messenger bike. Could it be done?
The only 2 speeds I'm aware of are the Sturmey Archer kickback hubs. They've been out for a year or two. They shift by backpedaling instead of having a shifter up on the bars. You can get them with or without a coaster brake so they could be used with hand brakes. They work well. I don't know anything about long term durability, but SA hubs generally hold up well. The two speeds basically work like a single speed, but with an extra low gear in case you hit a steep hill. I think the two rations are fairly far apart. There's so many multispeed internal geared hubs now (3 speed - 11+) that they cover most situations where you want more than a single. The only advantage of the 2 speeds is that there's no shifter, cable, etc.
There's no reason these couldn't be set up on pretty much any type of bike (though you do need to pay attention to the rear spacing in the frame of course). No one is strong enough to bend the chainstays on a frame unless there is damage or something has been done to compromise the integrity of the frame. There's no reason you can put MORE force on a frame/hub because you have fewer gears. It just means you'll have to pedal at higher torque more often because you can't optimize the gear ratio depending on your speed. People have been riding single/fixed for >100 years without an issue.
Thanks, Dave. I was thinking of torque during the breaking process, but now that I think about it, if the hub is secured well in the frame, there's no torque on the left chainstay from the coaster break attachment bracket -- that's just there to keep the hub from shifting or rotating in case a locknut is loose, right? Again, I'm a little out of practice thinking about these things.
I saw quite an assortment of 2-speed hubs on Amazon when I searched -- apparently for all kinds of applications, from retro balloon-tire beater to a lightweight.
Hmmm, looks like SRAM has a similar thing now too. I haven't tried one, but their other hubs are generally good.
I see what you mean now about bending the frame. No, I don't think it's an issue. However, a big issue with any non-derailleur set up is that you have to be able to adjust the chain tension. That means either horizontal dropouts, or some extra chain tensioner. (Or an eccentric bottom bracket).
There's been a real explosion of internal gear hubs in the last few years in the US. They have some weight and efficiency issues compared to derailleur systems. But they're super durable, weather proof, etc and I really love them for city bikes. SA even has a multi-speed "fixed" hub now if you're into the fixed gear thing, but want gear choices.
Thanks again! When I saw everyone going toward single-speed lightweights here in Chicago, I wondered about my old two-speed and their decades of good service with no maintenance needed. I remember opening one up just for fun and expecting something intimidating, but it was nothing like a three-speed hub -- just a few extra beefy cogs. And the 20-year-old grease was still clean. I cleaned and repacked the hub just for fun, and had it going again in 15 minutes. It's nice to see simplicity in vogue. Maybe the next thing I'll do is search Amazon for an update on the old Ashtabula crank.