Wednesday, October 5, 2011

SRAM Automatix (A2) vs. Sturmey Archer S2C

I'm in trouble. I've been thinking about my "next" winter bike. That is bad news, because I have neither the time nor the spare cash right now. Then again, I'm only thinking... thinking is free, right?

One of the most common problems with riding in a combination of salty slushy muck and sub-zero temps is that brake and shifter cables sometimes don't want to work properly. Careful attention to lubing them and "sealing" them from the elements helps, but careful attention isn't exactly my style. I have also been thinking about trying skinny rather than fat studded tires this time, but that's not what this post is about. Another post, perhaps.

With winter bikes, less is often more. There are two internally geared hubs on the market I am interested in (see title). Both offer two speeds and a coaster brake and both would eliminate the 2 cables normally running to the rear of the bike. In addition, a coaster brake will never be affected by wet/icy/slippery rims or brake rotors. For these reasons I am excited to build a winter bike that uses one of these hubs.

The SRAM Automatix (A2) shifts automatically. The S2C features a "kick shift", meaning that a little back-pedal will switch it between it's two gears and a harder back-pedal will engage the coaster brake. Gearing is very similar, with the S2C offering 100% (direct drive) and 138%, while the SRAM Automatix (A2) offers 1:1 and 1:1.37 gearing. The SRAM site shows a "bandwidth" spec of 124% while the Sturmey site lists an "overall range" of 138%. I must confess I'm a little confused... shouldn't the "bandwidth" of the SRAM be 137%? I'm hoping somebody smart will read this, comment and sort me out.

Another consideration is that the OLD (over locknut dimension) on the S2C is 116mm (although the axle is long enough to space it out far enough for 130mm rear spacings) while the SRAM OLD is 130mm. I tend to favour the 130 for potential frame (as in a bike I already own) reasons.

I almost wish one of the hubs was significantly less expensive than the other, but they both appear to retail for 60-80 bucks US, which is awesome in my opinion, considering what more elaborate internally geared hubs sell for. I'm further torn by the manual vs. automatic issue... if the auto works well, it is one less distraction while I'm riding in conditions demanding my full attention. On the other hand, I'm not sure I want to give up control of when the bike shifts! Arg!

So, what on earth am I gonna do? I've read some bikeforums stuff, but as usual there are arguments for both and they're most often about Bromptons and bikes like that. Can you, dear reader, offer me any insight? (Cafiend, any thoughts?) If so, please comment. Can you instead offer weird, incomprehensible ramblings? You should comment too, but I warn you that I might actually get you.

Note, July 24, 2012: When I wrote this post, I had no experience with either hub and still don't. However, there is a bunch of useful experience / performance info in the comments now. If you're considering a purchase, I strongly encourage you to read the comments on this post.

Yer Conflicted Pal,


recumbent conspiracy theorist said...

Sturmey Archer has been around for more than 100 years. That in and of itself is pretty amazing.

Is the low gear of either of these two hubs low enough for slippery snowy and icy conditions? I notice I shift to the really big cogs when things are super sketchy. I like your reasoning on the winter bike subject though -nice post.

RANTWICK said...

RCT - Both hubs are capable of taking a wide range of sprockets (S2C - 13T-22T, SRAM 15T-21T).

I will have to use some gear ratio calculators to arrive at a rear cog / front chainring setup that is, as you suggest, pretty low for the tough stuff and count on the hub to give me a little more speed when it is clear sailing.

No matter how I cut it though, this bike won't be capable of going all that fast.

Steve A said...

I like the S3X, but that white stuff on the ground is pretty rare at my house, though flurries may show up here by the end of the month.

Get the kick shift. If just seems more in tune with the "Rantwick Way."

PS: Not many isolated colorful trees. The pretty ones seem to be clumped together, no doubt as protection against predators.

Mighk said...

My one experience with auto-shifting was unpleasant -- one of the Shimano "Coasting" bikes. (Remember those? They were going to bring the masses into cycling...)

The shifting was clunky, and tended to shift late (at fairly high RPM; novices aren't comfortable with spinning).

I'd go with the kick-shifting.

GreenComotion said...

Auto stuff ain't no good! In my limited knowledge, I would compare that to an automobile with a bad cruise control mechanism, which does not accelerate / decelerate when necessary. So, please consider going with the manual...

Do those drum brakes really work?

I have a 30+ year old SA hub + <1 year old SA hub. Both work very well.

Peace :)

RANTWICK said...

Strong support for the Sturmey Archer and/or mistrust of things "automatic"... hmmm...

Anonymous said...

I've done ~2000km's on 20" folder with S2c starting from march this year (I was using back then studed tires, so, still was snow on streets).
Well, before I did few thousands on original Sachs duomatic. After that S2C was very big disappointment by means of shifting... Later it turned out that grease is for temperatures above +10C, bellow that shifting is disturbed.
One more thing- if you stay still and shift by kicking back, then move bike back, wheel locks(!)... You have to hit quite hard to pedals to go out from this situation. Huh. This can be done still after 2000km's and I manage to do this randomly. :)
Other thing- after first 100km's hub bearing adjustment came loose, nuts was tight. Tightened myself, no problems so far.
Hub has no any sealings, I think, I'll kill it this winter with salty snow. :)
So, I would suggest to try A2... :)

RANTWICK said...

Anon - That was some valuable info. Thanks very much. Thankfully, I guess, I'm still pretty far away from a purchase.

Studded tires eh? Always nice to hear from a fellow winter rider.

Anonymous said...

You can see few pics here:

About S2C coaster brake- it is much stronger than original Sachs duomatic, but quite difficult to dose, at least on 20" wheels.
But involving brakes means switch gear, so, if you choose S2C, have handy strong front brakes when don't want to switch gears.
I'm now curious about this A2, lusting to try it sometime. :)
Good luck!

Anon aka Martins

Anonymous said...

If 2 speeds without cables is what you're after, you might look into "retro direct". YouTube has some examples, and it certainly is diffeerent, and cool. Might try it myself with an old Corsaro frameset.


RANTWICK said...

KPete - Holy crap, that is cool. I had never heard of such a thing before. It looks a little too advanced for my negligible machanical skills though.

Anonymous said...

The way percentages are figured on internal geared hubs is just plain wierd, but we know from SRAM that in high the Automatix hub wil turn 1.37 times for every turn of the cog. If I did my math correctly, this would mean that with a 23 tooth cog, you would also effectively have about a 17. A very nice combo. Of course this is IF I did the math right.


iamwill said...

Thanks for the nice review.

I'm getting the Tern Verge Duo on February 2012 and hoping that the SRAM Automatix will perfrom well.


Anonymous said...

I've just found out about the SRAM Automatix. Wow. You can get one over there for $80?! They cost £90 here, which is the UK, so about $130. I think my knees nowadays demand something with more gears though.

David Spranger said...

Recently built up a new commuter bike with the SRAM Automatix. So far, I like it very much. Changes gears predictably between low and high and back again. Quiet, though high gear does have a ticking noise (I don't find it offensive or irritating at all). Cannot speak to reliability as I have less than 100 miles on it and all of that mileage is in good weather.

Robert Jack Wild said...

With the kick-back, when you brake in low gear, it puts you in high (because kick-back shift always precedes kick-back brake) which is quite stupid. So you'll need to create a habit of kicking back twice to brake. When cycling in a city where you often have to brake just a little and then again a little, this really sucks. (Haven't tried it yet, because the imagination alone makes me cringe.)

Max Ruzanov said...

Hi guys,
I've had awful experience with S2C hub and so far I went through 2 of them(!). I originally got one, built the wheel with it and had it for about 300-400km. It made all kinds of horrible noises, clicks, grinding, locking on itself, becoming loose and wobbly, shifting randomly, oozing grease on my wheel. Jeez. I've got replacement from SA for free, rebuilt the wheel and this new one seems to be even worse.
It is heavy too. I am considering SRAM's Automatix, its almost a pound lighter and has better reviews. I have some info about the hub (complaints mostly) and my bike here:

Anonymous said...

I went through 3 (!) S2C's in about nine months. I gather Sturmey Archer redesigned the hub earlier this year. My first two were the old model, the last one the newer version. It was slightly better, but basically stopped working after a couple of weeks. Shifting became very unpredictable; mostly it wouldn't shift at all. My bike shop has been great, but after the third S2C we just gave up. I've been riding an Automatix now for about a week, and so far I'm quite happy with it. It feels very solid, and is virtually silent (the S2C could be *very* noisy).

Phil Bickford said...

Thanks to you all for posting, and to our host Rantwick.

My three S2C hubs ( two new innards and one completely new hub) took three months to "wear out." The problems I had are similar to what others stated. In addition, #2 would shift itself when riding over rough terrain. The last hub skipped constantly in low. I'm baffled as to why they haven't been recalled. A number have worked for others but I've noticed they seem mostly to be hubs without brakes.

I've not found the SRAM Automatix available with coasterbrakes here in the states yet. Hopefully I'll find one soon. I'm about ready to purchase a straight single speed coaster hub, but would much prefer a two speed.

So far this seems to be the only blog or board that has this much on these hubs. Thanks for the opportunity to learn about them.

Phil B

Jerry said...

Yep I tried two S2Cs before giving up and fitting the SRAM A2. Fit and forget :)

I emailed S/A a few times and quite frankly found them rude and unhelpfull :(

raf said...

Got myself a TSr2 with SC2 hub. Very unreliable for me, it will kick shift at the slightest backward movement even when I don't intend to. And when you use your coaster brake, it of course will also change gear. It's ok if I am on 2nd and it drops to first since I am slowing down, but it's not right if it's the other way round. Overall very unhappy. Wish it's just a single speed, more predictable.

RANTWICK said...

Phil and all other commenters - thanks very much for your comments, because they have turned a post with no info on experience or performance into one that is, like, useful to people.

Sorry I took so long to approve latest comments - I was off the grid for a couple of weeks.

Kurt said...

Coming late to this discussion. I purchased an S/A SRC3 with coaster brake from Universal Cycles (2 years ago) and laced it into a 20" Alex rim for use with my Dahon Mu Uno. The hub lasted about 3 months. Same problems as Max, Anonymous and Phil. I emailed Sunrace Sturmey Archer numerous times but they never made things right. So I went back to the original 1-speed hub. Had hoped to use a SRAM Automatix but the shift point is too low for me. I need something around 15-18kph. Caveat emptor.

Anonymous said...

I had all of the same problems listed above with an S/A SRC3 I laced up for use in my Dahon Mu Uno. Hub lasted about 3 months. Multiple emails to Sunrace Sturmey Archer without any resolution going on 2 years now. Would like to try the SRAM Automatix hub but the shift point for 20" wheels is too low for my needs (15-18kph would work best). I would never again buy a Sturmey Archer product.

Simon said...

hi everybody, I have just had a B2C with Coaster break put into a new wheel, first ride from the shop gear changed nicely .... went to break and had LOUD CLUNKING noises come from the hub.

Contacted Sturmey Archer without much luck, have already purchased a SRAM Automatix once it arrives I will rebuilt the wheel with the SRAM hub.

Very Very dissapointing indeed you can follow the link below I have a vid of the Hub in action making the noise while breaking. I appologize for the rather crappy vid. It's hard to video with your phone and ride at the same time.

Simon said...

here is the Vid link of the issue I had with my Sturmey Archer 2 Speed Hub with coaster break. Everytime I break this is the sound it makes. I started from the first time I used the hub which was built into a new wheel.

Already ordered a Sram Auomatix ... very dissapointing, I have no idea whats wrong with it

Ingemar Ragnemalm said...

I have two Automatix wheels, one on my own bike and one on my son's. We are both very pleased with them. The gear shifting is really smooth, just a faint click and it shifts. It isn't always at the perfect gear but more often than not. My son had a standard 3-gear wheel before and he didn't like it it since it was too hard to adjust so the gears would work properly (worst in winter, obviously). He also had a Duomatic in the past and never thought that was a bad idea, but I think the Automatix has the edge.

Steve Hutera said...

I have a Sram automatic on my 87 fuji with 700c rims. First thing to note is that a normal size chain ring is to big for the gearing. I have reduced my front to a 38t which works perfectly. One odd thing to note is the hub is preset at the factory to automatically shift at 7 or 11 mph. There is no way to determine the setting before purchase or easy way to adjust the shift points.

Overall I'm impressed with it. Reducing the front chain ring to a 38t made a huge difference.

Everyone who has rode it has been impressed with it.

Anonymous said...

Stevee, I have the same problem, brand new hub, wheel built yesterday. No ideas here but very keen to hear if anyone has a fix!

Kurt said...

Steve, are you sure about the 7 & 11 mph points? That would make sense for a 20" wheel, not 26" wheel. The two points are determined by the number of spoke holes. The lower one is for a 36H hub, the higher for the 28H hub. According to SRAM, for a 700C wheel with 25mm tires, the shift points should be 16.8 kph (36H hub) and 20.6 kph (28H hub).

David Spranger said...

After about 6 months and well over 3000 miles, I can still say I am very satisfied with the SRAM Automatix. No trouble whatsoever. I did take it apart after about 200 miles and cleaned and re-greased the works. Factory lube was sparse. I have heard of some people changing the shift point up on the hub by changing the spring to one with higher tension. I can see how it is done, but I have not attempted it myself. I am okay with it shifting at ~12 mph using 700x38 tires.

Anonymous said...

Here's a good link with photos for anyone interested in attempting to adjust the shift point on the SRAM Automatix:

Very interested to try out the SRAM. I had a Schwinn years ago that had a 2-speed kickback (probably SA, but who knows). Of course that bike is long gone (stolen), but I still think fondly of it.

David Spranger said...

For the heck of it, I followed the instructions in the above link and was able to successfully move the shift point from around 12 mph to around 15 mph. If anyone else wants to try this, BE CAREFUL!! That circlip is very small and easy to drop and get lost!

Anonymous said...

This has been great advice! I'm building a project bike and almost jumped into an S2C. Thank you!

Anonymous said...

Very intersting. I am using the Sturmey kickshift, 700c on a 1938 Huffman. Ordered an Automatix this morning for my Norco cruiser that will be mounted on a 24" using a 3" tire. For the SA, rode 2000 kms on it and very pleased but the thing just wont shift below -10°C, a grease change would solve that problem but I wont do it. Both bikes get a front SA drum brake, weight isnt an issue with those bikes. My light one is a 1 speed Haro railer SS with a disk brake. Im not a winter cycling fan but surely will give a try at the Sram one just for the kick of it.

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