What are the pros and cons of internal gears?

  • I've had my hybrid 24-speed for a bit over 3 years now, and just last weekend, when looking for a bike for my wife, discovered internal gears. Suffice to say it blew my mind when I saw 7-speed internal gear hubs, for example on this This Giant Suede Women's bike.

    So the question is, what are the trade-offs between the internal gear hub and an external gear hub and derailleur?

    I'm assuming they'll be more expensive? but what about the set of gear ratios they provide? the reliability? the serviceability? tuning/maintenance? other effects on the chain/sprockets?

    Going back to the bike linked above, there's a near-identical model with 21-speed external gears that's considerably cheaper, and I'm wondering whether the extra money for the internal gears would buy any real benefits (e.g. longer lasting chains/sprockets or fewer services), or whether it's just for fashion?

    ...depends on your climate and geography. I have inner hub bike and XYZ-speed bikes. I use the inner hub bike during salty-snowy winters. During summer when I do longer rides, I like to use XYZ-speed bikes because there are a lot of hills, mountains -- where inner hub is not that comfortable, of course you can change the geometries but it is a hassle. If you want more targeted answer, you could mention weather/geography restrictions.

    for the sake of a useful answer for the community, i'll leave the question as is, though where I am it doesn't snow and i ride almost entirely on sealed surfaces - the biggest problem for my gears/chain is a bit of grit and occasional rain so not a hugely compelling reason to switch...

  • Correct answer

    10 years ago

    The main advantages of hub gears over a 1xN derailleur system are reliability and being able to shift while stationary. Since there's no derailleur or chain tensioner it's easier to add a full chaincase which means chains last a lot longer and with mudguards added there are no dirty bits accessible on the bike. They're heavier and harder to maintain if you have to maintain them.

    There's a whole style of bike that uses those advantages (and others) and from a US perspective is called a "european" or "dutch" bike. Broadly, it's a bike built for someone who is not a cyclist, rather they are someone who uses a bike for transport. It should just work, no special clothes or rituals required.

    Compared to a 3xN derailleur system a hub gear is much simpler to operate and maintain. All the gears are in order and you only have one shifter. The compromise is a smaller gear range (Rohloff being the obvious exception), ranging from a little smaller for the Shimano Alfine 11 down to "yes, there are two gears" for the back-pedal-shift 2 speed hubs. But in return you get extremely long life for the chain and cogs (10,000km or more for the chain, 20,000km+ for cogs) and a general low-fuss maintenance requirement. That also makes it practical to put a hub gear in places where derailleur gears could go but you wouldn't want them - under my load carrying quad, for instance, where the derailleur hung down between the rear wheels just waiting for a rock to break it off, and turning the thing over for maintenance is a pain.

    Removing the rear wheel on a hub geared bike ranges from nigh on impossible (some of the Shimano hubs, and some dutch bikes have chain cases that are just irritating to work on) to almost trivial (a Rohloff with QR). The problem is the shifter cable - you have to detach it to remove the wheel. Good ones just unhook, poor ones you have to undo the adjuster barrel and re-adjust the gears on reassembly. Shimano are getting better, but Rohloff and Sturmey Archer have it down pat.

    Servicing hubs is not often done these days. The manufacturers generally allow bike shops to swap out the internals for new, saving the hassle of building a new wheel, but that's about it. I had three Shimano Nexus 8 hubs fail at 5,000km intervals, and every time I just got replacement internals rather than the hub being repaired (the last time, of course, Shimano had stopped making the hub so I had to throw away the wheel). With Rohloff the same thing might happen, except after 150,000km or more... most people don't ride that far in a lifetime. Also, with Rohloff you change the oil every 5,000-10,000km, at a cost of half an hour of your time and about $20 for an oil change kit (or $10 for just the oil).

    I usually run a Schwalbe Marathon Plus on the rear of my hub geared bikes, which trades a little extra rolling resistance for huge puncture resistance. It's part of the "my bike just works" philosophy. I'd rather reliably take an extra 30s to get to work than at random intervals be 5-10 minutes late and dirty due to a puncture (because you know that you'll only get punctures when you're in a hurry and it's raining).

    I've been lucky to avoid punctures on my internally-geared bikes... mostly. Also, the Shimano Nexus hub is quite easy to remove and reattach; adjustment is a matter of lining up a yellow indicator in a window while the shifter is in the middle gear. I have yet to remove the SA on my other bike.

    @Neil: it depends which Nexus you have. Some of them require either lining up flanges on a plastic washer with matching indents on the hub then turning the locking bit, or slotting a cable end stop into the hub. Neither are necessarily easy - I've seen mechanics in a dry, well-lit workshop struggle with the former as it's not at all intuitive. Try the Rohloff sometime if you think Shimano is easy...

    @moz - Well, *this* Shimano is easy... :)

    Why do you spell "puncture" with an asterix?

    @Bartek: superstition - by mentioning something you call it to you.

    Good answer: +1. I've suggested an edit. It replaces "p*ncture" with "puncture". It also changes the post from using megameters to kilometers: megameters are confusing for most readers.

    I'm thinking of buying a Raleigh Twenty folding bike with a Sturmey-Archer AW three-speed hub. I thought the only maintenance it needs is a little oil every so often. But you wrote "if you have to maintain them": what does that phrase mean?

    unforgettableid: "if" means that most geared hubs can go long periods without any maintenance at all, but when they do need it it's often not obvious what needs doing. Adding a little oil is actually easy, but if you break or wear out the shift mechanism it's going to be harder to fix than the same thing on a derailleur system. Partly because it happens so much less often.

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