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.
Yer Conflicted Pal,
R A N T W I C K 
17 comments:
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.
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.
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.
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.
Patrick,
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 :)
Strong support for the Sturmey Archer and/or mistrust of things "automatic"... hmmm...
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... :)
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.
You can see few pics here:
http://s009.radikal.ru/i307/1103/18/3054e7d95cef.jpg
http://s60.radikal.ru/i170/1103/38/ed8ea728f2b3.jpg
http://s54.radikal.ru/i144/1103/8d/1ece8ff1a9fb.jpg
http://s016.radikal.ru/i335/1103/6f/223e837cf0b9.jpg
http://i024.radikal.ru/1103/36/45f7af4670bf.jpg
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
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.
KPete
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.
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.
KPete
Thanks for the nice review.
I'm getting the Tern Verge Duo on February 2012 and hoping that the SRAM Automatix will perfrom well.
Will
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.
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.
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.)
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:
http://uglyplastik.blogspot.ca/
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