Hub gear benefits are well-known to winter commuters. No more frequent maintenance to clear out 'mud glue' from your derailleur and instant changing (in theory at least) into any gear you want, whether pedalling or stopped. Try that with a rear derailleur only if you like listening to loud crunching sounds while going nowhere and damaging your drivetrain, and very possibly your shins at the same time.
The market for rear hubs with more and more gears has taken off in recent years, with the three main competitors, Shimano, SRAM and Sturmey Archer, going head-to-head. If you live in a relatively flat area, then a three-speed will suffice – I've run the Nexus Inter 3 without any problems for thousands of miles. However, find yourself tackling very hilly country or carrying loads regularly and you might want to think about more hub gears.
Enter the Shimano Nexus Inter-8. As the name suggests, there are eight gears packed into a hub weighing about 1.55kg (for the unbraked version that I tried – add 200g for the roller braked version). The range is an impressive 302 percent – fine for all but the hilliest of country and with a top gear to suit all but aspiring Chris Hoys. Gaps between the gears are reasonably evenly spaced, the biggest being between one and two – in effect giving you a very easy pedalling 'granny gear' in first, which makes sense as hill-climbing ability is what the hub is all about.
This all sounds good on paper but how did my 1,000-mile test work out in practice? Once the hub was installed in a 36-hole rim it was a fairly easy matter to slot on the sprocket and surclip and fit the rotary changer before sliding it into the frame (being the V-brake version meant no messing with torque arms and the like that make installing the hub-braked version tricky). The gripshift gear changer goes on the bars and I then zip-tied the cable the length of the frame. The trickiest bit was fitting the cable end into the rotary changer by slotting the cable end nut into a recess at just the right angle – once you get the knack, though, it's easy. A rear puncture shouldn't cause too many headaches.
Unlike three-speed hubs which run through a single epicyclic gear, those models with many more gears such as the Inter-8 work through more complex 'compound epicyclics' – in practice meaning that certain gears have a reputation for feeling and sounding 'grindy' or at least more inefficient than your average derailleur gear.
Once the system was bedded in I didn't feel this to be a problem at all. Because of the way the Inter-8 system works it has a reputation for being a little rough in the bottom few gears, but after 100 or so miles the noise died away and pedalling felt only marginally rougher than a well-maintained derailleur system in the bottom gears and just the same in higher gears.
Being able to change several gears at a time – even when stopped – is fantastic. Twist shifting has been consistent. Very occasionally the hub 'slips' between gears but this just requires a bit of tweaking of the cable tension adjuster which is handily at the shifter end of the cable, so you can adjust while on the go. The hub even survived having a bungee (one that became dislodged from the pannier rack) wrapped around it while pedalling fast and hard. The hub needed taking out and the sprocket refitting as it had slipped out of it's housing, but I was impressed that no damage was done by something that could have easily written off a rear derailleur. Even what I previously considered the rather flimsy plastic rotary changing mechanism came out unscathed.
What else is out there? Well, Shimano's eight-speed Alfine hub, with trigger shifters and disk brake option, gives similar performance to the Inter-8 but with less of a weight penalty (though more cost) and would suit racier riders pondering a low-maintenance option. Sturmey Archer produces eight-speed hubs and SRAM the legendarily strong S7. While both are more expensive (the S7 much more expensive), they don't suffer from the 'difficult to get spares' reputation that Shimano do. However, with the 'sealed for life' tag that comes with the Shimano Inter-8, spares shouldn't be a consideration.