4 ms·

As a former bicycle mechanic and salesman, and someone who is still very tuned into the industry, I'd give this a zero percent chance of actually being successf

As a former bicycle mechanic and salesman, and someone who is still very tuned into the industry, I'd give this a zero percent chance of actually being successful. There are three big issues with this design. First of all, you're going to be looking at a seriously increased Q factor trying to fit three different speeds into that gearbox (as opposed to Truvativ's two). The Q factor is the amount of distance between your feet. If you lie down on your back and make a pedaling motion, the natural positioning of your feet is one banana apart. Bikes, to have sufficient stiffness in the bottom bracket region, space your feet two banana's apart or more. Graeme Obree (https://en.wikipedia.org/wiki/Graeme_Obree https://en.wikipedia.org/wiki/Graeme_Obree) figured that out, and when he designed Old Faithful he added a very narrow Q factor, which was a big piece of his success. A huge benefit of carbon fiber is its ability to add stiffness in the BB area by overbuilding without increasing Q factor (or weight all that much), hence the BB30 standard. Truvativ's two-speed front crank is already very widely spaced, and trying to fit more in is going to cause problems. Remember, to balance out the pedal stroke, you have to compensate on the left pedal (I see this is designed to work with existing tech, but it'll feel strange unless you get a longer left pedal spindle), so every increase in distance on the right side is doubled. Secondly, no part on the bike gets worn out quite like bottom brackets (not including "wear" parts like chains, cassettes/freewheels, tires, etc.). Powerful riders (and not necessarily racers, I know plenty of everyday commuters who fit this bill) tear BB's to shreds. I am a racer, but I'm also a lightly built climber, and I tear through them pretty regularly. Putting a gear box in the BB shell is going to subject it to a hell of a lot of torque, and it'll be difficult for it to stay dialed in and functional with the power output of many riders. The extra mass could also make it uncomfortable to stand up and power out of the saddle. Trek, Pinarello, and a few other companies already reinforce the non-drive side of some of their bikes to even out the extra weight from the chainrings and front derailleur. All the extra mass from a gear box will expound this. And lastly, internally geared systems are a bitch to maintain, and it's one of the reasons why you will be hard pressed to find a shop which will overhaul your vintage three-speed hub. The newer internally geared systems (like Shimano Alfine and Nexus) are a lot easier to work on, but Shimano spent decades perfecting that stuff. This system is not going to be easy to work on to start, and good shop owners don't sell products their mechanics can't fix easily. It's just not a good proposition. All in all, a cool idea, but to me far too many issues for it to ever be accepted. As that bikeradar article puts it, no need to reinvent the wheel. Internal hubs and derailleurs (the latter especially) get the job done quite well.

jrockway 14y ago
Came here to say this. Internally-geared rear hubs are great for certain mountain bikes, where derailleurs just won't work because there is too much mud. But for everyone else, a well-adjusted derailleur system will be fine. (Yes, you have to pedal forward to change gears. If you're stopped at a light, press the front brake and move the pedals forward. Or remember to downshift as you're braking.) I've thrown a chain twice in recent memory: once when I was climbing on a chain where I disregarded the rule against breaking the chain without replacing the pin with a master pin (that you break off after driving in), and once when I was trying a new kind of lube on the chain (that worked more like glue than lube). A well-maintained derailleur system is very light and very efficient, and with a bit of practice, easy to use.
- Too 14y ago
  Mud always comes up in these discussions but isn't a real problem. You can get mud, water, sand, branches, snow, grass, gravel or entire bushes into your gears and hardly notice it. Sometimes it feels like the whole forest just wants to go into your gears but in some magical way it always falls out again. The more i think about it the more amazing i think it is, the amount of punishment the powertrain takes is quite remarkable and even though the components are so small and precise they don't take much damage. The only real problem with derailleurs in the forest is when they get hit by a rock, a think branch or the ground. Anything else that doesn't actually bend the derailleur is a non issue. In very very rare occasions something might jam the chain but no changes in the gear are going to fix that. And of course the mud will slowly wear and tear things down by grinding but that's not an issue of the actual gear but more of the cogs and chain.
  - jrockway 14y ago
    Ah yes, the derailleur thing sounds like the real issue that internal gearing aims to fix.
snogglethorpe 14y ago
My reading of the article suggests that it's targeting more casual riders that bop around town, but maybe live in a hilly place, haul kids, etc, and could use some extra gearing. All your criticisms may be true, but seem to be more about the needs of "enthusiast" / "serious" riders (a category which includes many bike commuters in the U.S., but not so much in other countries). So despite the issues you mention, there may very well be a place for this tech—and the "non-serious" market is much larger (especially outside the U.S.)...

jrockway 14y ago

Came here to say this. Internally-geared rear hubs are great for certain mountain bikes, where derailleurs just won't work because there is too much mud. But for everyone else, a well-adjusted derailleur system will be fine. (Yes, you have to pedal forward to change gears. If you're stopped at a light, press the front brake and move the pedals forward. Or remember to downshift as you're braking.) I've thrown a chain twice in recent memory: once when I was climbing on a chain where I disregarded the rule against breaking the chain without replacing the pin with a master pin (that you break off after driving in), and once when I was trying a new kind of lube on the chain (that worked more like glue than lube). A well-maintained derailleur system is very light and very efficient, and with a bit of practice, easy to use.

Too 14y ago
Mud always comes up in these discussions but isn't a real problem. You can get mud, water, sand, branches, snow, grass, gravel or entire bushes into your gears and hardly notice it. Sometimes it feels like the whole forest just wants to go into your gears but in some magical way it always falls out again. The more i think about it the more amazing i think it is, the amount of punishment the powertrain takes is quite remarkable and even though the components are so small and precise they don't take much damage. The only real problem with derailleurs in the forest is when they get hit by a rock, a think branch or the ground. Anything else that doesn't actually bend the derailleur is a non issue. In very very rare occasions something might jam the chain but no changes in the gear are going to fix that. And of course the mud will slowly wear and tear things down by grinding but that's not an issue of the actual gear but more of the cogs and chain.
- jrockway 14y ago
  Ah yes, the derailleur thing sounds like the real issue that internal gearing aims to fix.

snogglethorpe 14y ago

My reading of the article suggests that it's targeting more casual riders that bop around town, but maybe live in a hilly place, haul kids, etc, and could use some extra gearing. All your criticisms may be true, but seem to be more about the needs of "enthusiast" / "serious" riders (a category which includes many bike commuters in the U.S., but not so much in other countries). So despite the issues you mention, there may very well be a place for this tech—and the "non-serious" market is much larger (especially outside the U.S.)...