£70 two-speed hub with coaster brake
Fatally flawed, great if it works
The Sturmey Archer S2C is a hub full of golden promise within its very specialised niche – without any cables at all, you get a low/high gear and a brake, with good efficiency and reasonable weight.
If it wasn’t sold off the shelf with a serious mechanical fault requiring the end-user to rebuild it with a new part shipped out by Sturmey Archer (yes really), and didn’t fatally explode after a few hundred miles, it would indeed be great – but more on that later.
Update: my hub exploded, locking up in the frame while I was riding. Scroll to the bottom for conclusions.
Unlike with a 5+ speed, with the Sturmey Archer S2C you need to think in terms of building a ‘sensible singlespeed’ rather than a hub geared alternative to a derailleur bike. It flips between 1x and 1.4x (say, 50″ and 70″, or 60″ and 84″).
Previously I had a fixed-wheel running about 65″, so in other words, it’s geared to ride quite a lot faster (and climb a lot better) than my old fixed, but the range is miles off what you’d get even with a single ring and 11-32 (which could do 30-106″).
First, the good
Compared with other hub gears I’ve used (the Sturmey Archer 5 and 8 speeds and the Alfine 8), the S2C is extremely efficient.
The low gear is direct (the sprocket is locked to the hub shell, effectively the same as a track hub), while the high gear goes through a single ‘step-up’ planetary assembly. I can’t identify any friction in high gear; that doesn’t mean it isn’t there (in fact I’m certain that obsessives could measure it without particularly high-tech lab equipment)… just that I can’t distinguish it riding through the real world.
With the coaster providing invisible braking, the Sturmey Archer S2C does build up into a very clean rear end – it needs a reaction arm secured somewhere to the frame, but I was pleased to discover that the slot disc mount on my Pompetamix is perfect for a clean attachment as you can see in the image above. Very stealthy!
The only other way to get something like this is to ride fixed with your back brake removed. The brake is smooth and strong and easily modulated, although it’s worth noting that you can ‘bite’ extremely hard if you put the pedals back hard.
I almost came a cropper when I absent-mindedly tried to rotate the pedals backwards to 3 and 9 o’ clock while standing up to jump over a kerb. The bike suddenly and dramatically slowed down under me as I came out of the saddle, I slowed down and mis-timed my kerb lift… but luckily the sensible tyres came through for me!
116mm OLN means you’ve got to be bold… or get a new frame
Unlike most hub gears, which either come in ‘normal’ (~132.5mm) or at least normal and track widths, the Sturmey Archer S2C is only available in the eyewateringly-small 116mm OLN. The axle is not long enough to space it out for even a 130mm aluminium frame, sorry.
If you have a steel frame however, which can basically just be bent (cold set) as you please, it is possible just to fit the S2C by springing in the stays (indeed my 135mm Pompetamix has not been cold set, I just stuck the S2C in there and did it up, and it’s not exploded so far). Placing the locknuts inside the dropouts adds another few mm on each side to ease the situation. Caveat experimentor!
The above is a stock 135mm-spaced Pompetamix rear end on a stock S2C axle. The plate to the right is the hitch for my awesome Carry Freedom Y-Frame trailer.
Probably no good in winter
The bearings on the Sturmey Archer S2C are not only unsealed, but practically begging to be contaminated. There’s not even any kind of contact seal at all – the balls are basically peeping out of the side of the hub shell and are lightly covered by a metal ring, which I’m sure doesn’t keep out rain of any strength.
You can see these in the photo above (the non-anodised light sections to the outside of the hub flanges).
I’m prepared to give it the benefit of the doubt for now – and it can be easily maintained in truth – but it’s a far cry from the S5C, which I ran for a whole winter with nary a whiff of trouble.
Broken off the shelf, requires user disassembly
The original wheel I assembled for my utility bike was a Sturmey Archer S5C – a five speed hub with coaster brake. How that went wrong is a story for another day, but I ended up buying an S2C in my quest for robust simplicity.
However – no sooner had I assembled the wheel than I realised it was unrideable in the the lower gear (direct drive) – even going downhill without pressure on the pedals, the slightest rotation of the cranks caused horrendous crunching and pinging. Another failed hub!
To cut a long story short, I chased this back to Sturmey Archer – who essentially admitted that the S2C was produced with a piece missing – but never mind, I could have the piece mailed out and fit it myself in the mysterious guts of the device!
As the hub is relatively cheap and simple, and I’m not afraid to break things, I decided to go for it and managed to effect the repair myself – disassembling the hub completely, breaking apart the drivetrain pieces and fitting a thick flanged spacer to support the suspect part.
Here you can see the hub inner. From top to bottom: the brake shoes, the direct-drive ratchet pawls, the planetary with high gear pawls (these change in and out to toggle the selected gear ratio).
It was amazingly messy and to make a successful job of it you will need C-clip pliers and cone spanners of the correct (nonstandard) sizes to tighten everything up. You’re trying to get the piece in between the two subsections that have pawls on the picture above… the long-term implications for the life of the hub have yet to be seen, naturally, and who knows whether anyone will warranty it now I’ve had to perform a triple heart bypass!
S2C repair detail
Since I found it extremely difficult to work out what was wrong with my hub until I heard back directly, I’ve uploaded the two documents provided by Sturmey Archer in the hopes that they will be useful to others:
It’s evidently taken almost a year for pre-fix hubs to still be working their way through the supply chain, so that’s okay then… 🙁
Despite repair, exploded and locked up in the frame
A short time after effecting the above ‘repair’ to the S2C, I was riding along on the flat sea front when the wheel suddenly locked within the frame. Luckily I was just pootling at 20mph or so and not out of the saddle, so I managed to control the skid.
One of the pawls within the hub had cracked in half, found its way across to the brake (or possibly just jammed some other part of the shell) and bang!
Needless to say, this killed the hub stone dead after just a few hundred miles. An extremely poor performance and as a result, I can’t honestly recommend the S2C hub at all.
I’ve bought a SRAM Automatix – see my in-depth review of that instead!