internal gear hub
anyone used a new gearhub? i’ve been looking at the rohloff (dreaming about is more like it) and the sram imotion 9, i know there is also the shimano nexus line… i just want to talk to someone who has one of any of these and if they are worth the investment/ if i can take it for a ride!
this is an ancient post, but I’m digging it back up b/c I’m thinking about putting an internal hub in an old mixte I have lying around for a commuter.
Any new thoughts on this issue? Mark — did you ever get one of these hubs? If so, which? You like?
howdy! i think i already had a nexus 8 at this point and i was curious about trying some other ones out just to see what was out there and what people thought.. i rode the nuvinci and a rohloff since then… still haven’t found and imotion from SRAM. the rohloff was nice but i actually found my nexus 8 to have just as good if not better shifting (no where close to the same range as the rohloff, and 1/6th the price).. the nuvinci was cool, heavy, and for some reason i just don’t trust it (probably not a good one).
the new alfine 11 has an oil bath lubrication system and a killer gear range, but costs 2 or 3 times more than the nexus 8…
i think nexus 8’s are great and there is a bikeshop through the liberty tubes that kind of specializes in cleaning and maintenance for them (i’ve never been there, just met the owner a couple months ago by chance) that would probably help you put it together if you don’t want to do it yourself (i’d also be happy to help you if you do want to do it yourself but you aren’t quite sure about everything, its not quite like putting any other rear wheel on)
I have no experience with anything other than the Sturmey Archer 3-speeds. I’ve had an old one, probably from the 60s or 70s, and currently use the new version on one of my around town bikes. I’ve never had any issues with either of them whatsoever, as long as the cable was properly adjusted. If its too loose you can grind second gear while in third, I don’t know how much damage can really be done to it that way though.
The only drawbacks are having only 3 gears (that is, if you consider that a drawback) and it being really heavy. I’ve never used them, but I imagine that the ones with more gears are even heavier.
I’m pretty sure Kraynicks has a bunch of NOS 3-speed wheels upstairs that would get this going without breaking the bank. I even saw an old Sachs one with a drum brake which was pretty cool.
I <3 SA 3 spds. I haven’t checked this, but i’d be willing to bet that a 3 speed hub is not much, if any, heavier than a road hub with gear cluster and derailleur combined, that’s really the equivalency. I may have to do some actual weighing.
it is a pound or two heavier depending on how nice the parts are that the hub is replacing… someone did this with a bunch of different hubs vs a 105 road double a couple years ago… derailleurs, cassette/sprockets, chain rings, shorter chain, less cabling/housing, cable stops, 1 less shifter… they pack a lot of stuff in there!
If we’re getting really picky, there is a lot more rotating mass in the internally geared hub and I’m no expert on the mechanics of it but I’d bet that you lose more power to friction and whatnot with the 3-speed hub.
But why am I bashing them so much? They still rule.
the mass is all pretty centrally located, so it doesn’t have near the same angular momentum as it would if it were located near the wheel. i imagine the difference would be very slight.
And for friction, the insides are packed with grease. Lots of it, I expect.
The figures I have heard are 92% efficiency of internal gears vs 98% of a derailleur system. You’d notice this most at low speeds and going up hill. I certainly notice a 3W dynamo when pedaling up hill, and that’s less than the loss of the internal gears.
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