What sort of wizardry is at work to enable three gears to be squeezed inside a hub?
Most hub gears use ‘planetary gearing’ to achieve their different ratios. It’s an incredibly elegant and relatively simple solution, but one that is pretty difficult to describe in words. This video helps to explain how they work far better than I can from 2.58 onwards.
How much does the hub weigh?
Approximately 1.1 kilograms - about the same as the unmodified hub.
What’s the gear range?
The Sturmey Archer website lists the hub as having an overall gear range of 177% with gear steps of 33%. I find the easiest way to think of it is that the hub has a direct drive gear (1:1) along with an over-drive gear at 3:4 and an under-drive gear at 4:3.
Why does the hub only come in a 36 spoke hole variant?
Although Sturmey Archer list the S-RK3 and RS-RK3 hubs on their website as being available in both 32 and 36 hole forms, the 36 hole version is the only one available to buy. Generally speaking 36 hole hubs are less common, but there is still a good range of compatible rims from companies that include Mavic, Stans, H Plus Son and Velocity, plus you also end up with a slightly stronger wheel. The CS-RK3 side steps this issue by being available in the UK in both versions.
Can I buy spares for the hub?
One of the benefits of using a Sturmey Archer hub as a starting point is the availability of spare parts. Most parts can be bought individually at reasonable prices, from a single pawl spring to an entire set of internals. Just about the only thing that you can’t buy is a new hub shell body. If you need a replacement part that has been produced or modified by us then please just get in-touch.
Won’t I also need to buy a shifter as well as the hub?
Unlike some other hub gears, where you are likely to need to buy a separate sprocket, shifter and fitting kit, a Sturmey Archer hub comes complete with an 18t sprocket, non-turn washers and a thumb shifter for mountain bike handlebars.
Aren’t hub gears less efficient when compared with derailleurs?
There has been a study that compared the efficiencies of different hub gears and derailleurs, which concluded that three speed hubs and derailleurs are broadly similar in efficiency terms. The poor reputation associated with the efficiency of some hub gears tends to come from those hubs with more than three gears. This is because this is most often achieved by essentially combining the mechanisms of multiple three speed hubs together (in VERY simple terms). So a five speed hub is, mechanically, essentially two 3-speed hubs bolted together (you tend to only get five gears rather than six when you combine two three speed hubs because you can only ever have one direct drive gear). This is also the main reason why some hub gears with more ratios can feel a bit spongy at the pedal.
Didn’t my Gran have a Sturmey Archer hub on her shopper bike?
Quite possibly. They’ve been around since 1902. A description of the long and often turbulent history of Sturmey Archer can be found here.
Don’t Sturmey Archer hubs have a reputation for jumping out of gear, leaving you in a false neutral and a possibly uncomfortable collision with the top tube?
Not any more. With early hub designs it used to be possible to find a ‘false-neutral’ between second and third gears. However, the current three speed hub design, with N.I.G., solves this issue. This video helps to explain how this current hub design works.
When can I buy a hub and what will it cost?
I’m still not sure, but if I do decide to start selling the hub I’ll only do so when I’ve proved to myself that they are reliable for general off-road use. Even then I will most likely only sell a relatively limited number to begin with to see how they hold up under different riders and in different conditions. As for pricing, this is something that I’ll look into only once I’ve decided whether I’m going to sell the hubs.
Most hub gears use ‘planetary gearing’ to achieve their different ratios. It’s an incredibly elegant and relatively simple solution, but one that is pretty difficult to describe in words. This video helps to explain how they work far better than I can from 2.58 onwards.
How much does the hub weigh?
Approximately 1.1 kilograms - about the same as the unmodified hub.
What’s the gear range?
The Sturmey Archer website lists the hub as having an overall gear range of 177% with gear steps of 33%. I find the easiest way to think of it is that the hub has a direct drive gear (1:1) along with an over-drive gear at 3:4 and an under-drive gear at 4:3.
Why does the hub only come in a 36 spoke hole variant?
Although Sturmey Archer list the S-RK3 and RS-RK3 hubs on their website as being available in both 32 and 36 hole forms, the 36 hole version is the only one available to buy. Generally speaking 36 hole hubs are less common, but there is still a good range of compatible rims from companies that include Mavic, Stans, H Plus Son and Velocity, plus you also end up with a slightly stronger wheel. The CS-RK3 side steps this issue by being available in the UK in both versions.
Can I buy spares for the hub?
One of the benefits of using a Sturmey Archer hub as a starting point is the availability of spare parts. Most parts can be bought individually at reasonable prices, from a single pawl spring to an entire set of internals. Just about the only thing that you can’t buy is a new hub shell body. If you need a replacement part that has been produced or modified by us then please just get in-touch.
Won’t I also need to buy a shifter as well as the hub?
Unlike some other hub gears, where you are likely to need to buy a separate sprocket, shifter and fitting kit, a Sturmey Archer hub comes complete with an 18t sprocket, non-turn washers and a thumb shifter for mountain bike handlebars.
Aren’t hub gears less efficient when compared with derailleurs?
There has been a study that compared the efficiencies of different hub gears and derailleurs, which concluded that three speed hubs and derailleurs are broadly similar in efficiency terms. The poor reputation associated with the efficiency of some hub gears tends to come from those hubs with more than three gears. This is because this is most often achieved by essentially combining the mechanisms of multiple three speed hubs together (in VERY simple terms). So a five speed hub is, mechanically, essentially two 3-speed hubs bolted together (you tend to only get five gears rather than six when you combine two three speed hubs because you can only ever have one direct drive gear). This is also the main reason why some hub gears with more ratios can feel a bit spongy at the pedal.
Didn’t my Gran have a Sturmey Archer hub on her shopper bike?
Quite possibly. They’ve been around since 1902. A description of the long and often turbulent history of Sturmey Archer can be found here.
Don’t Sturmey Archer hubs have a reputation for jumping out of gear, leaving you in a false neutral and a possibly uncomfortable collision with the top tube?
Not any more. With early hub designs it used to be possible to find a ‘false-neutral’ between second and third gears. However, the current three speed hub design, with N.I.G., solves this issue. This video helps to explain how this current hub design works.
When can I buy a hub and what will it cost?
I’m still not sure, but if I do decide to start selling the hub I’ll only do so when I’ve proved to myself that they are reliable for general off-road use. Even then I will most likely only sell a relatively limited number to begin with to see how they hold up under different riders and in different conditions. As for pricing, this is something that I’ll look into only once I’ve decided whether I’m going to sell the hubs.