Daniel needed to replace an aging Sturmey Archer internally geared hub on his road bike. More modern internally geared hubs are proving to be very reliable and having low drag, so he selected a Shimano Nexus 8 speed internal hub.
One of the biggest advantages of internally geared hubs is that all the parts are contained within a sealed unit – being the hub shell. They are well protected from water, dirt and road grime. It is hard for gunk to clag up your shifting mechanism, so there’s consistent smooth shifting. A conventional derailleur runs the risk of being bent, broken or knocked out of adjustment, as hanging down from the dropouts is very exposed, especially on MTBs. An internal hub, is difficult to damage.
Internal gear hubs are easier to maintain than derailleur systems over the short term. All you need to do is keep the proper tension on the chain and keep it lubed. With a derailleur and cassette you have to clean the system to keep it shifting smoothly. Keeping the chain and cog on an internally geared hub clean is important, but it’s not as much work, or required as frequently.
The chainline on an internal hub is usually straight and does not have multiple gears and pulleys to pass over/through, so it wears at a slower rate. With each shift on a traditional derailleur, the chain actually flexes and twists somewhat. The theory is you need to replace the chain more often. With an internal hub, even if you do need to replace the chain or cog, it’s simpler and cheaper.
An internally geared hub can shift gears while stationary. A traditional derailleur system needs you to be pedalling to change. As a result, internally geared hubs can be great for riding in stop and go city traffic. Commuters love them.
However, they are considerably heavier than freehub based rear hubs (but the difference closessignificantly once you add up derailleurs and cogs) and all that weight sits in the middle of the rear wheel (which is one reason why MTB riders have not taken them up).
Other disadvantages are that the gearing range can be limited (but gearing is usually usefully wide these days) and that if something does go wrong, rebuilding one is not for the impatient!
We laced it up to the indestructible Hplusson SL42 rim in a striking polished silver, with DT Champion spokes and brass nipples for reliability.