Different Gearing Systems Explained
We offer a wide range of Electric Bikes for diverse uses and users. Within all the brands we sell there are different models featuring different specifications and price points. Included in that specification, are a choice of gearing options. Below, we have detailed what each gear system is and how they work.
The idea of gearing is simple: when we turn the pedals, that energy gets sent to the rear wheel making the bike move via what is normally called a drive train.
Using a ratio of bigger and smaller cogs, when input is transferred from your feet to the drive chain, those different configurations help to get you moving swiftly and efficiently, and of course with some added eBike assistance too!
Electric Bikes by law in the UK have to be pedalled to enable the assistance. On the majority of them you will still find some type of drive chain as gearing systems are still needed and they can help refine the assistance the bikes give.
Pedals, chains and cogs have been on bikes for almost 200 hundred years, the derailleur shifter on your handlebar works to push the chain up or down over a set of gears or sprockets to change the gearing ratio, helping the rider to go faster or climb easier. The standard derailleur is usually the lightest and cheapest of the gearing systems, and on some mountain bike applications can give a huge range of gears. The downside of derailleur gears is that the moving gearing system is open to the elements and can be at risk of damage if the bike falls over or could be hit by debris while being ridden off road and at risk of corrosion being exposed to the elements (a very Brighton issue). Because of the price and the big gearing ratios, this system is most common on entry level bikes or most mountain bikes where climbing off road requires a big range of gears. Another thing to remember about derailleur gears is that the bike has to be pedalled to change the gears.
Single speed systems are the simplest of bike gearing. The main reasons for using a single speed drivetrain are to keep the bike as simple as it can, and in a flat city/ commuting situations one gear can be an advantage. The compromise of only having one gear is that when starting off a lot of effort is needed to get up to speed. When you're then at cruising speed, you're stuck with that same gear ratio so are limited to how fast you can go before you spin out the pedals. Plus, when that inevitable hill comes along things can become tricky, but this can be partly negated by electric assistance.
Internally geared hubs
Like the Sturmey Archer hubs of old, the internal gearing system or hub gears work by shifting a set of cogs and gears inside the hub to give a select number of gear ratios. By keeping all the cogs and moving gearing parts inside the hub all you need is a single drive chain component like a chain or carbon belt, which keeps costs down. More important though is that because all the moving parts are safely tucked away, they’re protected from damage, dirt and corrosion (especially important in the coastal conditions of Brighton!), and the hub needs minimal maintenance. One thing to consider with internally geared hubs is that with the convenience of having everything neatly tucked away inside the wheel hub is that they can be slightly heavier and more complex if something goes wrong, however issues are quite rare. With internally geared hubs one of the benefits are that you have to stop pedalling to shift the gears meaning that you can change the gears while stationary.
Two specialist internally geared hubs that we do are the Enviolo and Rohloff hubs.
Enviolo is unique as it uses a clutch type of system which basically means that it doesn’t have any steps between each gear. As you rotate the grip shifter, on its display you have a little person on a bike that moves into an uphill position to show that the bike is in an easier gear and a flat position showing that you're in the higher gear. Having the ability to change while on the flat, Enviolo is a great system for someone that struggles with the complexity of traditional gears. You can even move away from changing the gears yourself completely by choosing the Enviolo Automatic gear system. This uses input from Bosch to intuitively change gear for you, leaving you with nothing to do but enjoy the ride!
Rohloff is the crème de la crème of internal gearing systems. Traditionally favoured by the round the world bike tourers. The Rohloff speed hub has 14 stepped gears, much more than any other hub manufacture and is known for being extremely reliable with a huge gearing ratio. On Bosch based systems the hub is shifted electronically meaning that the hub perfectly shifts every time with the added bonus that there is no risk of cable stretch affecting the smooth operation of the gears. Additionally with the electronic shifter, the gears are changed with the push of a button meaning there’s no twisting of the wrist. A consideration of the Rohloff hub is that with all these amazing features the hub itself is one of the heavier on the market, but that’s unnoticeable when being ridden in any level of assistance.
If you have a particular gear system you are interested in having on your eBike, we are very happy to talk about what models feature your preference!
- Lucy Rowe