FAQ: Internal Vs External gears
You may have noticed that internally geared hubs are becoming more and more popular on bicycles. Internal gears have been around since the early 20th century and became hugely popular in the 1930’s. So why did everyone switch to derailleurs? And why should you reconsider an internal hub?
The derailleur and the internal gear hub were actually invented around the same time. A 2-speed hub was patented by William Reilly of Salford, England in 1896 and French bicyclist Paul De Vivie invented a 2-speed derailleur in 1905 which he used on his rides in the Alps. The initial designs were both a bit clumsy and difficult to shift but the two technologies yielded essentially the same result. While advancements in derailleur technology meant bikes could have more gears, for years internal hubs were limited to about 3 gears such as on the well known Sturmey Archer hubs. They were still quite popular on utility and urban bikes and remained the gearing system of choice in European countries where bikes were used mainly for transportation rather than sport or leisure. They were reliable, almost maintenance free and practically bomb-proof. But at the time they couldn’t provide a wide range of gears.
While the derailleur and cassette still dominate today’s bike market, there has been constant advancement in internal gear hub technology. Once limited to 3 gears, internally geared hubs are now offered in 8, 11 and 14 speed models. These new internals can even cover the same gear range as a 24 speed cassette and derailleur system. Now that internal gear hubs have broken free from their previous limitations there are many reasons to consider using one on your bike.
One of the biggest advantages of the internal gear hub is that all the moving parts responsible for shifting are completely contained in a sealed unit – the hub. This means they’re completely protected from water, dirt, road salt and grime. With no outside contaminants to possibly muck up your shifting mechanism, you can always count on your internal hub to shift smoothly from one gear to the next. An exposed derailleur also runs the risk of being bent or broken, and a derailleur hanging down from your dropouts is fairly prone to being knocked out of adjustment. An internal hub, on the other hand, is pretty difficult to damage.
Maintenance and Longevity
Internal gear hubs are easier to maintain than standard derailleur systems. The main thing you need to do is keep the proper tension on your chain and lubricate it periodically. With a derailleur and cassette system you have to clean your rear cogs and derailleur regularly to keep them shifting smoothly. It’s not uncommon to have to adjust the limit screws on your derailleur from time to time either. And while keeping the chain and single cog on an internally geared hub clean is important, it isn’t nearly as much work.
Since the chain on an internal hub is always in a straight line and doesn’t have multiple gear wheels and pulleys to pass over, it also creates less wear and tear. Every time you shift from one cog to the next with a traditional derailleur, the chain actually flexes and twists a bit. You’ll find you need to replace your chain much more often with this system and may even need to replace your rear cogs at some point. With your internal hub, even if you do need to replace the chain or single cog, it’s a lot simpler without the derailleur getting in your way.
I may have saved the best for last here. Have you ever come to a stop on your bike and realised you’re still in much too high of a gear to start in? With an internally geared hub you can shift gears while stationary. Unlike a traditional derailleur system, you don’t need to be pedaling to change gears. This can be great for riding in stop and go city traffic and can also make it a lot easier to down shift on a steep uphill.