The iO ID is a limited-run steel hardtail from Shimano distributor Madison, using the new Shimano Alﬁne eight-speed hub gear. A development of the Genesis iO singlespeed, the ID’s direct chainline and internal gears should cope well with British mud.
Ride: hub gear makes for fuss-free transmission
On the trail the iO ID's Shimano Alfine hub feels fairly efﬁcient – more egg whisk than pepper grinder. You can shift when pedalling, although you need to back off the pressure a bit. There’s a noticeable clunk going from fourth to ﬁfth because you’re changing two sets of gears simultaneously – like using front and rear derailleurs at the same time.
If it doesn’t feel as tautly efﬁcient as a derailleur setup, it’s not too far off. Advantages include no mech to wreck, shifts when muddy or stationary, and a stronger, dishless rear wheel. On the ﬂip side, you’ll need to carry a spanner to get the rear wheel out.
Frame: tidy steel
The frame’s main triangle uses a lighter chromoly steel tubeset than the basic iO. Reynolds 725 is still plenty strong, which is why the head/down tube gusset is so minimalist. At the rear, track-ends do the job of chain tensioning, and the dropouts are ﬁtted with bolts (whose small Allen heads could round off…) to help align the wheel. Slotted disc mounts allow for fore-aft wheel movement, and there are frame ﬁttings for commuter use.
Components: Shimano hub gear gets dirty
On the road is where the Alﬁne hub is normally found; ﬁtted to town bikes and sporty hybrids.
Its migration off-road is down to its disc mounts and 135mm over-locknuts axle spacing. Shimano has given the hub the green light for cross-country use. Essentially the Alﬁne is an improved Nexus Inter-8. The internal gears turn on bearings rather than bushes, so the Alﬁne feels slicker and should last longer. The axle is apparently stronger, too, and a double roller clutch makes for smoother shifting.
Gear ratios are the same as the Nexus: 0.53, 0.64, 0.75, 0.85, 1 (oddly, not direct drive; you’re going through spinning hub internals to get one-to-one), 1.22, 1.42 and 1.62. With the 18T sprocket ﬁtted, that’s like having a 10-29T cassette. Although the chainring is 32T, that still means seventh and eighth gears are used only occasionally.
If you wanted to gear it down you could ﬁt a bigger rear sprocket – the Alﬁne is available up to 23T.
The rest of the bike, from the geometry to the components, is largely what you’d expect on a good, bread-and-butter hardtail. The RockShox Recon XC air fork works well and is easily tunable for rider weight with a shock pump. It lacks the motion control of the more expensive Reba, so it’s tempting to sit in the saddle rather than attack climbs – a tendency that’s exacerbated by the hub, good though it is.
Psychologically and physically, there isn’t the same drivetrain bite you get when the drive is going solely from chainring to sprocket, so you’ll be winching rather than sprinting up climbs.
The bash-guarded Hone chainset is simple and sturdy, as it ought to be – it usually goes on jump bikes. Perhaps because