Brompton had the right idea going with internal gear hubs for their folding bikes. There's something about the way an internal gear hub hides the gears in a shiny metal tube that makes it a bit magical. I mean, do they honestly fit 3 gears inside that little hub? Aren't bicycle gears normally those big toothy disks on the back wheel? I don't see any toothy disks... what gives?
Well, first of all: yes, there really are 3 gears contained in that hub. And to preempt your next question: yes, they are just as evenly spaced as normal gears. In fact, Brompton has even designed a special wide range hub for use with its 6 speed bikes which works in concert with its two speed derailleur system to evenly space the gearing from low to high. Even though internal hubs have been around for a long time, people still have a lot of questions about them. Something about their clean look seems to prompt people to verify whether they are too good to be true. Let me tell you from the beginning: internal gear hubs are the best option for most people.
The Brompton M3L, our number one most popular Brompton, is ideal for commuting thanks to its 3 speed internal hub. You see, 3 speeds is pretty much the maximum that any commuter needs. The gearing is well spaced to account for hills, flats, and descents alike. You have one speed for starting up and for hills, one speed for gentle inclines and slower speeds, and one speed for cruising and descending. This pretty much covers the terrain encountered by the average commuter and is ample flexibility for most of our customers. Of course, if you live in a particularly hilly or flat area you can raise or lower the gearing to some degree to suit your situation.
Keeping your Brompton folding bike running smoothly is a snap with an internal hub. Because the hub comes greased and sealed right from the Brompton factory you can be sure of a good adjustment and with all the gears neatly packed inside you also greatly reduce wear and tear on the drive train. With only one sprocket outside the hub the chain is always in perfect alignment. This significantly lessens wear on the chain, chain-ring and sprocket. I'm sure you'll agree that the less you have to get your bike tuned up and adjusted the better, and with an internal hub you get just that.
On top of being clean and low maintenance, an internal hub is also easier to use. It eliminates the possibility of binding the chain between gears when shifting by allowing you to shift without pedaling. That means you'll never be stalling out on hills trying to shift to a lower gear.
Historically the Brompton 6 speed was criticized for not having evenly spaced gearing and Brompton was working hard to solve the problem without sacrificing a universal frame design. The problem was that in order to fit more gears Brompton would either have to go with a wider and heavier internal hub with more gears or change the design to accommodate an external gearing system. Both solutions were out of the question. Instead, engineers completely redesigned the Sturmey-Archer 3 speed hub, giving it a wider range and reducing its weight, a win-win. Now, modern bikes with the Brompton Wide Range hub have a very evenly spaced gearing comparable to most modern road bikes. Just as with the 3 speed you can adjust the gearing on 6 speed Brompton's to fit your terrain.
When it comes to commuting with a Brompton folding bike, there is nothing better than an internal hub. Folding bikes should be simple to use, practical and useful machines. That's why we point most of our customers to Brompton bikes with internal hubs. It just makes everything easier. I hope this article has cleared up some of the confusion about internal hubs and in particular their use with the Brompton. To build your own Brompton and pick the perfect gearing use our very special custom Brompton folding bike tool. Enjoy.