New three-speed fixed gear hub

First – I hope people realize that this blog is mostly to write down my ideas so I don’t have to think them up again later, right?
Secondly, it might be useful to someone else who’s thinking along the same lines. Those people are pretty few, but you know who you are.

In that vein, here are my thoughts on the new Sturmey-Archer S3X, an internally-geared three-speed fixed-gear hub. More info, including a schematic, and the proposed colors can be seen on the Sturmey-Archer SunRace blog.

What is it?
A hub-gear that lets you change gears without deraillers, like the old Raleigh 3-speeds. What it doesn’t do is let you coast.

Why would you want that?
Because it’s COOL. I don’t like to coast. I like fixed gear bikes. I like the feel of the drivetrain, I like the challenge of the uphills and the down. I like them.
But if the challenge is so fun, then why a multi-speed fixed gear? Because I have one now, but I have to monkey with the wheel to change gears. I like to ride my bike, and the places I’ve lived have always had hills. Sometimes mountains right in the middle of your ride, and dirt trails are harder to climb than paved roads.

What is that S3X EXACTLY?
It’s a three-speed fixed hub that has a wide gear ratio of Direct Drive (the most efficient, 1:1 gear), 2nd gear at -25% of 1st, and 3rd at -37% of first.

This gear spread is like the old Sturmey-Archer 3-speed AW hubs most people are familiar with. The gears are not like the uber-rare Sturmey-Archer ASC 3-speed fixed gear hub it most resembles otherwise. In 10 years, I’ve known maybe five people on the internet who say they’ve owned one. The AW was one of the longest-lived bike parts ever, possibly one of the longest-lived mechanical items of any kind. The ASC was kind of cultish from the start, and was made for British time trialists (race against the clock on public roads). The ASC had a narrow gear range for optimum efficiency over roads that weren’t that steep, ridden by real hard riders. The AW was made for a wider range of landscape, load and rider.

The people I’ve heard complain on the internet about the “useless” wide gear range of the AW and the new S3X have never backed up their assertions (to my knowledge) with any data about their own multi-speed fixed gear riding.

I think this hub is awesome, and I’m actually going to save up, and possibly sell something to afford one at the $140-$160 pricepoint it’s rumored to have. To see how it meets my needs, I’ll sum them up.

Here’s my multi-speed fixed-gear riding experience:
I’ve had a Rivendell Quickbeam for almost 5 years, and run 42″ to 74″ gears on it. The QB has 40t and 32t chainrings, a 15t and a 17/21 Dingle cog. I also have a Ross touring bike with 40/44 tooth rings and the same Dingle cog for a 70″ and 51″ gear combo.

I’ve pushed my 70″ gear over Sonoma Mountain, and taken it 50 miles through Occidental. I should’ve dropped down to the 32 for Sonoma Mountain, but I wanted to see if I could do it in the big gear. I’ve ridden out to Sweetwater Springs Road in the 72″ gear, dropped down to the 57.6″ gear and rode over it. Multispeed fixed gear is my favorite thing. I also like brakes.
I’ve ridden the 57″ gear up Mt. Tam’s and Mt. Diablo. 57″ is too high to climb Diablo comfortably for me. I’ve offroaded the bejeezus out of the 41″ gear (Surly Dingle cog, another awesomely great invention). Intellectually, the 41″ gear is way way too low, but in practice it’s really really good.
For general riding I like a 70″ gear, but I’ve gone as low as 64″ and as high as 74″ for periods of time.

Given that background, and this upcoming hub, I’m interested in being able to run a a 70″, 52.5″, and 44″ gear, or 84-63-53 to put the normal gear in the middle and have a bigger top end. A stronger rider or a road-only rider may prefer this to the 70″ direct drive, but I’ve been really liking that 42″ climbing gear! Someone who only rides down hills might like a 94-70-60, too. That actually looks pretty good for long flat rides, but I’ve never lived places like that.

For the riding I do, I could be happy for a long time with the 70-52.5-44, or a 72-54-45. No fussing with the wheel at the bottom of the mountain to change gears, no fussing with the fender as the wheel moves back in the dropout to tighten the chain with the smaller chainring.

It looks like the Sturmey Archer S3X will have 12 and 13 tooth cogs, which seem smaller and more wear-prone than bigger ones, but they’d save some weight and minimize the chances of people ripping up the internals with a tiny ring and a big cog.

Real gear choices from the S3X:
My favored 70″ to 72″ top gear could nicely be gotten with any 30 to 34 tooth chainring, and a 40×13 looks pretty nice at 83-63-53. It would be a different set up than I’ve got, but the larger gear would last longer. I’ve got a couple 40t rings, 63″ isn’t so bad for noodling around town, and steep descents would be a lot easier. Maybe too easy.
A 36×12 would give you 81-61-51, and a 40×12 puts out 90-68-57.
would give you 99-72-62, for all that Southwest Louisiana road riding you do.
All calculations arrived at with Sheldon’s Gear Calculator of course, and rounded for simplicity.

Fantasy gear choices using a Schlumpf:
Tom Shaddox (New Golden Age of Gear Bashing pt. 42) points out that an S3X running 36×15 with a 2009 Schlumpf Speed-drive would be a perfect set of six fixed gears: 113″, 85″, 71″, 65″, 49″ and 40″.

See your own choices:
Here’s my Google Docs spreadsheet of the S3X’s gears. The Excel formulas I used look like this:
A3: desired top gear B3: =A3-(A3*0.25) C3: =A4-(A4*0.37)

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UI/UX Designer, bike nerd, artist.

4 thoughts on “New three-speed fixed gear hub”

  1. I too cannot wait for the S3X. My only concern is the loss of efficiency that comes with planetary gears and the possible play in the non-direct gears. I am hoping that the middle gear really is “direct drive” as they claim. Then I would do most riding on the direct drive gear and only use the other two for ascents and descenets.

  2. I've now had my SA s3x out for a couple of rides, and I like it. It has a couple of drawbacks, but nothing serious, so far. Check out my blog @ for more on it, if you're interested.

    BTW, the top gear is 1:1, not the middle.


  3. Some of them are sloppy out of the box, so adjust the cones properly to reduce the risk of slipping (there are false neutrals between the gears). There is quite a lot of noise and resistance in the lowest gear, but no worse than a new SRF-3, and that hub runs in quite nicely over the first 200 miles. The hub is apparently based on the latest 5-speed design, which is why top gear is direct drive. The ASC was similar, being a hack of the contemporary 4-speed.

  4. Took me time to read the whole article, the article is great but the comments bring more brainstorm ideas, thanks.

    – Johnson

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