So, I'm currently dithering about two potential bikes, either of which would ideally have a Rohloff DB hub if cost wasn't an object. As if!
One is the Surly Krampus, which takes a normal 135mm rear hub but has limited clearance for double chainrings, and would thus require moving the RH crank out. I'd prefer not to do this due to an old knee injury which means it's better for me to keep the cranks as far inboard as possible, which makes 2x10 less viable. If I stick with an IGH that problem goes away, and crank choice is limited only by chainstay clearance.
The other potential bike is at least a few months away yet, and would be a low Q fatbike with chainstays elevated to clear the crankarms, and symmetrical 135mm hubs front and rear. I'm currently doing an evening engineering course so would like to have a go at making this a bit later in the year. There's almost zero chance I'd ever ride on snow so could stick with narrower rims (probably 47mm, or maybe 65mm) and 3.7-4" tyres on the back; I'd most likely use a Moonlander fork so anything would fit on the front. To get any chain/tyre clearance with a 73mm BB and low Q standard crankset the chainline needs to stay as far outboard as possible, so derailleurs won't work; my knees really don't want to know about 100mm BB shells or the cranks that go with them.
The situation with the Krampus is similar; 1x10 is possible but won't give a low enough gear for the local climbs, and XX1 is too spendy and the Q156 cranks won't clear the chainstays. While SS would work (mechanically), my knees would explode very quickly, so that's not a realistic option.
That leaves IGH, which I'd prefer anyway, the options being:
* Alfine 8: Cheap, reliable, takes standard CL rotor, but limited range, big gaps between some gears, "backwards" shifting action. 47mm chainline is okay for Krampus but not enough to clear fat bike tyres.
* Alfine 11: Wider range & mostly closer ratios (except 1st to 2nd) than A8, "normal" shifting action, but much more expensive than A8, finicky adjustment, many reports casting doubt on reliability. Same chainline as A8.
* Nuvinci 360: CVT so no gaps between gears, standard rotor (IS), reasonable price, but very heavy, may be less efficient in lower gears than others, not user maintainable - and I'm in Australia so this is a problem(!). 49mm chainline is plenty for a Krampus but still marginal with fat bike tyres; might be doable with an offset 10 speed bottom gear cog if that would clear all the shifting gubbins - anyone know if there's any room to spare outside the standard flat cog?
* Rohloff: Reliable, wide range of gears with close enough gaps (similar to A11), widest chainline @54mm so most tyre/chain clearance, but very expensive, and I would need the most costly variant for the Krampus as it's disc only, plus rotors are expensive too [sigh].
There are 47mm 26" trials rims available ex-Europe that will work with narrower fat bike tyres, so a rim brake could be used on the rear, potentially saving a few hundred dollars on the Rohloff when duty an taxes are considered. Still, all Rohloff hubs are expensive, and I'd prefer to avoid used in light of recent experiences.
Seems to me like the cheapest, easiest solution is to forego fat tyres and stick with derailleurs, but as a former Australian Prime Minister once infamously said, "Life wasn't meant to be easy."
Suggestions, anyone? (Apart from psychiatric help that is!) If I've ignored any other sensible options, please do tell...
Mtbr's 2016 Winter Biking GearReviews and Roundups
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