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Author seems to think an internal drivetrain for a bike would be more reliable. Maybe somebody more mechanical can chime in, but my understanding was that the o

by mindB 9y ago

Author seems to think an internal drivetrain for a bike would be more reliable. Maybe somebody more mechanical can chime in, but my understanding was that the opposite was true: only reason cars have to use an internal drivetrain is for cooling and external ones are generally more reliable?

CompelTechnic 9y ago
External drivetrains are exposed to dirt and debris, which wears down the bearing faces quickly. There are certain bicycles that use partially enclosed chains and sprockets for which chain maintenance is greatly reduced.
- username223 9y ago
  Bearing faces? Most bikes have sealed bearings these days, so there's no need to overhaul your bearings after riding in the rain. The chain and cogs need some cleaning and lube, but modern dry chain lube also makes that much less onerous.
  - reportingsjr 9y ago
    Just because bearings are sealed doesn't mean debris can't get inside of them. This is particularly a problem for bottom brackets bearings since they are so large (more area for stuff to sneak in) and because it is easy to force material inside of them when spraying a bike off with water.
CydeWeys 9y ago
One of the problems with external drivechains on bicycles is that they're exposed to all sorts of harsh elements like rain, mud, and road salt in winter. Even ignoring that, unless you have good parts and you're really on top of your maintenance and constant adjustment, it's pretty easy to have the chain slip or not engage properly on the chainring/cogset when shifting.
mitchtbaum 9y ago
This looks like an interesting approach. Perhaps there's a better, universal way to do it: Nuseti mountain bike features a sealed drivetrain - New Atlas https://newatlas.com/nuseti-inner-drive-system-mountain-bike/32914/ https://newatlas.com/nuseti-inner-drive-system-mountain-bike...
jakobegger 9y ago
Internal gears in bicycles need no service at all for typical use. External gears on the other hand require you to swap chain and cogset regularly. (But if well serviced, they are more efficient)
- mindB 9y ago
  Ah. I think I was getting robustness and efficiency mixed up. I suppose if you have sufficient electric assist, efficiency becomes less of a concern.
  - jdietrich 9y ago
    Internal gearhubs are marginally less efficient than a clean and well-maintained derailleur system, but they're considerably more efficient than a dirty and neglected derailleur system.
jdietrich 9y ago
Internal gearhubs are drastically more reliable than derailleur gears and require almost no maintenance. They use an epicyclic gear train in a sealed oil bath, so most of the mechanical parts are protected from moisture and foreign objects. The use of a gearhub also facilitates the use of an enclosed chaincase, or a belt or shaft drive. The Sturmey Archer 3-speed gearhub has existed largely unchanged since 1938 and is faultlessly reliable, even when horribly neglected. As long as they're rebuilt every 10,000 miles or so, they'll last a lifetime. They're the standard gearing option on Dutch utility bikes and were once the most popular of all bicycle gearing systems. The only real downside of the Sturmey Archer gearhub is that it offers a narrower range of ratios than a derailleur system, although it's more than adequate for utility cycling in moderately hilly areas. Newer gearhubs offer eight, eleven or fourteen ratios, matching the gear range of a mountain bike derailleur system. They're less popular than derailleur gears because of the higher cost and marginally higher weight, but I think that they're a vastly superior choice for utility cycling. One great advantage for casual cyclists is that gearhubs change smoothly and instantly, even under heavy pedal load or at a complete stop. Changing gears on a derailleur system requires a degree of finesse to avoid jerky changes and dropped chains. Rohloff manufacture the most sophisticated of all gearhubs, which have been successfully used on several round-the-world tours.
- analog31 9y ago
  Yup, I have 2 Sturmey-Archer 3-speeds in regular use, that are both 50+ years old and both have been virtually maintenance free. Of course my legs aren't as strong as an electric motor, but an e-bike could have a beefed up gearhub.
- mindB 9y ago
  Can you buy bikes that come with internal gearhubs on the consumer market, or is this always an aftermarket thing nowadays?
  - jdietrich 9y ago
    Yes, although they can be somewhat hard to find in some markets. Any Dutch or German bike shop will have a wide selection of bikes with gearhubs, but in the US you might need to speak to a dealer that specialises in urban utility bikes. Some department store cruiser and hybrid bikes have Sturmey Archer 3-speed gearhubs, although the rest of the bike may be mediocre. Dahon and Tern are both manufacturers of folding bicycles and both offer a good range of bikes with gearhubs. Folding bikes can be a very practical choice even if you don't use the folding feature very often - they're compact, agile and easy to ride.

by mindB 9y ago

CompelTechnic 9y ago

External drivetrains are exposed to dirt and debris, which wears down the bearing faces quickly. There are certain bicycles that use partially enclosed chains and sprockets for which chain maintenance is greatly reduced.

username223 9y ago
Bearing faces? Most bikes have sealed bearings these days, so there's no need to overhaul your bearings after riding in the rain. The chain and cogs need some cleaning and lube, but modern dry chain lube also makes that much less onerous.
- reportingsjr 9y ago
  Just because bearings are sealed doesn't mean debris can't get inside of them. This is particularly a problem for bottom brackets bearings since they are so large (more area for stuff to sneak in) and because it is easy to force material inside of them when spraying a bike off with water.

CydeWeys 9y ago

One of the problems with external drivechains on bicycles is that they're exposed to all sorts of harsh elements like rain, mud, and road salt in winter. Even ignoring that, unless you have good parts and you're really on top of your maintenance and constant adjustment, it's pretty easy to have the chain slip or not engage properly on the chainring/cogset when shifting.

mitchtbaum 9y ago

This looks like an interesting approach. Perhaps there's a better, universal way to do it: Nuseti mountain bike features a sealed drivetrain - New Atlas https://newatlas.com/nuseti-inner-drive-system-mountain-bike/32914/ https://newatlas.com/nuseti-inner-drive-system-mountain-bike...

jakobegger 9y ago

Internal gears in bicycles need no service at all for typical use. External gears on the other hand require you to swap chain and cogset regularly. (But if well serviced, they are more efficient)

mindB 9y ago
Ah. I think I was getting robustness and efficiency mixed up. I suppose if you have sufficient electric assist, efficiency becomes less of a concern.
- jdietrich 9y ago
  Internal gearhubs are marginally less efficient than a clean and well-maintained derailleur system, but they're considerably more efficient than a dirty and neglected derailleur system.

jdietrich 9y ago

Internal gearhubs are drastically more reliable than derailleur gears and require almost no maintenance. They use an epicyclic gear train in a sealed oil bath, so most of the mechanical parts are protected from moisture and foreign objects. The use of a gearhub also facilitates the use of an enclosed chaincase, or a belt or shaft drive. The Sturmey Archer 3-speed gearhub has existed largely unchanged since 1938 and is faultlessly reliable, even when horribly neglected. As long as they're rebuilt every 10,000 miles or so, they'll last a lifetime. They're the standard gearing option on Dutch utility bikes and were once the most popular of all bicycle gearing systems. The only real downside of the Sturmey Archer gearhub is that it offers a narrower range of ratios than a derailleur system, although it's more than adequate for utility cycling in moderately hilly areas. Newer gearhubs offer eight, eleven or fourteen ratios, matching the gear range of a mountain bike derailleur system. They're less popular than derailleur gears because of the higher cost and marginally higher weight, but I think that they're a vastly superior choice for utility cycling. One great advantage for casual cyclists is that gearhubs change smoothly and instantly, even under heavy pedal load or at a complete stop. Changing gears on a derailleur system requires a degree of finesse to avoid jerky changes and dropped chains. Rohloff manufacture the most sophisticated of all gearhubs, which have been successfully used on several round-the-world tours.

analog31 9y ago
Yup, I have 2 Sturmey-Archer 3-speeds in regular use, that are both 50+ years old and both have been virtually maintenance free. Of course my legs aren't as strong as an electric motor, but an e-bike could have a beefed up gearhub.
mindB 9y ago
Can you buy bikes that come with internal gearhubs on the consumer market, or is this always an aftermarket thing nowadays?
- jdietrich 9y ago
  Yes, although they can be somewhat hard to find in some markets. Any Dutch or German bike shop will have a wide selection of bikes with gearhubs, but in the US you might need to speak to a dealer that specialises in urban utility bikes. Some department store cruiser and hybrid bikes have Sturmey Archer 3-speed gearhubs, although the rest of the bike may be mediocre. Dahon and Tern are both manufacturers of folding bicycles and both offer a good range of bikes with gearhubs. Folding bikes can be a very practical choice even if you don't use the folding feature very often - they're compact, agile and easy to ride.