21 Feb 2014, 11:49
So, hub gears aren't directly that much easier on chains, although you do maintain perfect chainline at all times with one, so the chain always runs straight, which does help matters some.
However, they enable a few things that are easier on chains.
First off, because you're not derailing the chain and needing it to fit between sprockets, 1/8" pitch chain can be used (and many IGH setups come with sprockets that require it, in fact, although you can convert everything to 3/32" sprockets if you prefer, and Rohloffs only support 3/32" sprockets). This means you can get a hell of a lot more life out of a chain.
Then, because you typically tension the chain by moving the hub back and forth in the dropouts or track ends (converting an existing vertical dropout frame will require a chain tensioner though), or moving an eccentric bottom bracket, you can then easily put a chaincase on, and protect the entire chain from dirt even hitting it. Can't do that nearly as effectively with derailleur gearing.
Oh, and you can also shift at a complete stop, no having to shift before you stop.
The main downsides to IGH... cost is a bit high (OK, for a Rohloff it's REALLY high, but that's an absolutely bombproof hub), weight distribution is quite rear-biased (and some hubs are friggin' heavy (I'm looking at you, SRAM G8), but even for the lighter ones, you're moving weight that used to be distributed around the drivetrain to the center of the rear wheel), shifting under load is generally a bad idea (even if the hub maker says you can do it, it's still a bad idea - on the flip side, though, you can stop pedaling for a split second, shift, start pedaling, and you're instantly in the gear, no need to wait for the chain to jump to the sprocket), and quick releases are almost unheard of in the IGH world (unless you go Rohloff).
As far as what hubs are good... I'll talk about the manufacturers first. Sturmey-Archer tends to give quite good support for their hubs, at least in the US, with spare parts and all if one needs to be rebuilt. Shimano... their version of spare parts support is "here, you can buy an entire internal assembly", not just the part that broke. SRAM depends on where you are, in the US, they barely even acknowledge that they make any hub gears, but in Europe, I hear that their German office (which is basically what's left of the bicycle part of Sachs after SRAM bought them and their hubs up, and is the division of SRAM that actually designs the hub gears) provides decent support.
Everyone makes a good 3-speed nowadays, although Sturmey-Archer's is kinda legendary (and it's what everyone else's is based on), and works in narrower frames than the others. Also, there's a few different shift cable layouts for 3-speed hubs - the indicator chain method that Sturmey-Archer's been using since 1902 (which comes out of the axle, outside of the frame), the bellcrank method that Shimano uses (also outside of the frame), the clickbox that Sachs/SRAM used to use for everything, but SRAM only uses on the DD3 now, which isn't what you want (it's a 3-speed IGH that takes a 8, 9, or 10-speed cassette)), and rotary shifting (which is inside of the frame, and Sturmey-Archer (optional) and now SRAM use it)
Going beyond that... 5-speed means you're looking at Sturmey-Archer's S50(W) family, C50 family, or a Shimano Nexus 5-speed that's only intended for Asian markets (edit: or not, the post I had read claiming that was wrong). The original S50 had a bad track record, but the S50(W) does fine AFAIK. The S50 has indicator chain shifting, the C50 has rotary shifting, and not sure about the Nexus 5.
The Nexus 7 is, AFAIK, also a decent hub. No direct drive gear, but then, many IGHs don't have their direct drive gear in a useful place, so...
Then you get to the 8-speeds. No point in getting the SRAM G8, it's way too heavy and has mediocre range. The Shimano Nexus 8s are good, the Alfine 8s are really good, from what I've heard. The Sturmey-Archer S80(W) has wider range, although it's quirky as hell (first gear is direct drive - GREAT for small-wheeled bikes), and isn't that efficient in higher gears, but they don't blow up like the original S80s did, so there is that. I've got one on my recumbent trike, and generally like it.
Beyond that... the last options left are the Alfine 11 and the Rohloff 14. You're paying a lot either way, it's just whether you pay a lot, or an arm and a leg. The Alfine 11 is a much weaker hub, but is sometimes seen as a "poor man's Rohloff".
Last edited by
bhtooefr on 22 Feb 2014, 20:24, edited 1 time in total.
This should be a Kaiser Idell 6556 ...
