Author Topic: Sturmey-Archer S3X 3-speed fixed - who's interested?  (Read 34276 times)

Sturmey-Archer S3X 3-speed fixed - who's interested?
« on: August 02, 2009, 04:07:12 pm »
Derek at Old Bike Trader has e-mailed me thus:

Quote
Hello all
I have just had news that the S3X hubs are at sea on the way to Europe and should be available late August, on confirmation of arrival in the UK I will notify cost and delivery details.
So I can confirm my order quantity with my supplier please let me know if you require more than one unit or have friends or colleagues who wish to purchase the hub also.
Regards Derek.

Derek is at oldbiketrader@aol.com

There are pictures of the hub in the new SA catalogue:

http://www.sturmey-archer.com/pdfs/Sturmey-Archer_2009-2010_Catalogue.pdf
Never tell me the odds.

Re: Sturmey-Archer S3X 3-speed fixed - who's interested?
« Reply #1 on: August 02, 2009, 04:57:56 pm »
A bit OT, but it was interesting looking in their catalogue.  They do the X-RK8, which looks like it could be useful for a disc-braked commuter.  I wonder how it compares with the Alfine, it certainly seems to be a bit cheaper.

I quite fancy a disc braked, hub geared commuter, but I think the S3X fixed approach may be a bit too much for me.  Yes, I know, I'm chicken! ;D
Actually, it is rocket science.
 

Re: Sturmey-Archer S3X 3-speed fixed - who's interested?
« Reply #2 on: August 02, 2009, 06:28:34 pm »
The Sturmey 8-speed is nowhere near as good as the Alfine, or even the Nexus 8.  Chris Juden of the CTC tested it and didn't like it; the big problem is that direct drive is 1st gear and everything is geared up from that.  This means you end up running a ring and sprocket combination like 28 x 20 for climbing, and suffer inefficiency in all the most frequently-used gears.

Back on topic, the gear ratios of the S3X are 62.5/75/100 i.e. direct drive is top.  This isn't ideal either (you want your cruising gear to be direct drive)  but apparently it's not possible to make a fixed 3-speed that works otherwise.  The old ASC was the same basic setup, although with closer ratios.  On the other hand, the power losses in a mere 3-speed hub - assuming only one planetary geartrain in use at a time - are minimal and on a par with a really good clean derailleur system.

I was thinking of running 48 x 15, which would give gears of about 53"/63"/85" with 23c tyres.  I'd normally ride 48 x 18 fixed (about 70"), but that's just to get me down the hills without blowing the front tyre off the rim with brake heat.  63" would be much nicer on the flat.  The hub could be left on the bike all the time; 85" is great for TTs and it would be as efficient as a normal fixed gear.
Never tell me the odds.

Re: Sturmey-Archer S3X 3-speed fixed - who's interested?
« Reply #3 on: August 03, 2009, 10:21:21 am »
I guess for most folk the price (incl for the shifter) will be something of a deciding factor!
Let right or wrong alone decide
God was never on your side.

clarion

  • Tyke
Re: Sturmey-Archer S3X 3-speed fixed - who's interested?
« Reply #4 on: August 03, 2009, 10:36:39 am »
I think it is very interesting as a unit, but price is definitely an issue...
Getting there...

Re: Sturmey-Archer S3X 3-speed fixed - who's interested?
« Reply #5 on: August 03, 2009, 12:31:26 pm »
Genuine question: why is it important for ones "cruising gear" (by which I assume you mean that most often used) to be "direct drive"?

Let right or wrong alone decide
God was never on your side.

clarion

  • Tyke
Re: Sturmey-Archer S3X 3-speed fixed - who's interested?
« Reply #6 on: August 03, 2009, 12:32:05 pm »
Greatest efficiency.  

In either of the other two gears, you are turning more gears, so there are greater losses.  It's a damn shame it's so difficult to have a fixed that is direct in the middle, then an overdrive for downhills, and a lower gear for hills or eadwinds. :(
Getting there...

Re: Sturmey-Archer S3X 3-speed fixed - who's interested?
« Reply #7 on: August 03, 2009, 01:05:20 pm »
"there are greater losses"

Thought that would be the answer - but are the losses sufficient to be a real issue for a potterer like me?
Let right or wrong alone decide
God was never on your side.

LittleWheelsandBig

  • Whimsy Rider
Re: Sturmey-Archer S3X 3-speed fixed - who's interested?
« Reply #8 on: August 03, 2009, 01:39:31 pm »
Interested, how much?
Wheel meet again, don't know where, don't know when...

clarion

  • Tyke
Re: Sturmey-Archer S3X 3-speed fixed - who's interested?
« Reply #9 on: August 03, 2009, 02:58:46 pm »
"there are greater losses"

Thought that would be the answer - but are the losses sufficient to be a real issue for a potterer like me?

Given the figures for hub gear losses, which seem to be just higher than average for a derailleur system (though higher than a well-maintained one), I would suspect that the efficiency of an indirect drive on this unit is comparable to a derailleur equipped bike </pure speculation>
Getting there...

robbo6

Re: Sturmey-Archer S3X 3-speed fixed - who's interested?
« Reply #10 on: August 03, 2009, 04:18:11 pm »
Plenty of people put up with the inefficiency of freewheel hub gears for pottering.

Quote
Interested, how much?
I saw on a SA blog nearer $200 than $400, the writer was being very cagey about a price, this was in the winter.

clarion

  • Tyke
Re: Sturmey-Archer S3X 3-speed fixed - who's interested?
« Reply #11 on: August 03, 2009, 04:23:44 pm »
Yup.  Cagey they have been.  I'd want to know much more precisely before I commited.
Getting there...

Re: Sturmey-Archer S3X 3-speed fixed - who's interested?
« Reply #12 on: August 03, 2009, 05:04:54 pm »
Supposed to be $160-$190, so reckon on the same in pounds, since we always get shafted.
Never tell me the odds.

Re: Sturmey-Archer S3X 3-speed fixed - who's interested?
« Reply #13 on: August 03, 2009, 05:06:12 pm »
Whilst the "effeciency loss" sounds well within my standards, I strongly suspect the price will not!

I'll hazard a guestimate - hub plus bits and bobs and shifter - min 250 quids, max 350.
Let right or wrong alone decide
God was never on your side.

Re: Sturmey-Archer S3X 3-speed fixed - who's interested?
« Reply #14 on: August 03, 2009, 06:55:57 pm »
I wouldn't have thought so.  A new S-RF3 is only about £70, and you can get one built into a Merc wheel for £40 (then throw away the rim and spokes).  Obviously there will be a fashionista premium, but I don't think they can charge Rohloff prices for an SA product made in Taiwan.

The bits and bobs, if you're going to do it properly, are a fulcrum clip for your top tube and a pulley for your seat cluster (attached to the seat tube).  Never run the cable via the BB - it either needs loads of outer or it will get chewed by the chain when you fix a puncture.

True obsessives can have these things done as braze-ons  :-[

EDIT: anecdotal evidence here says €150, which is about £130.

velospace forums - the s3x should be launched in the u.s. by now
Never tell me the odds.

robbo6

Re: Sturmey-Archer S3X 3-speed fixed - who's interested?
« Reply #15 on: August 04, 2009, 07:53:25 am »
On  another OT note, I see that SA are introducing bar end changers for their freewheel hubs.

clarion

  • Tyke
Re: Sturmey-Archer S3X 3-speed fixed - who's interested?
« Reply #16 on: August 05, 2009, 03:04:22 pm »
On another thread, I speculated about my wish to have interchangeable S3X and hub geared rear wheels, but Simon Galgut wisely pointed out chainline problems.  The figures are these:

                                   OLN                                   CL

S3X                             120/130                             42, 43, 44, 45

iMotion 9                     135                                     48.8

Rohloff                         135                                     52

Is there a way I can span these gaps & make a viable swap?  I guess the stays can be built as 132mm & sprung to fit, but is the chainline problem a showstopper?  It's less than 4mm difference, but I don't want to risk a chain coming off.  Is there a busk?  Or could I change the chainline enough at the cranks when I change the wheel?

Getting there...

Re: Sturmey-Archer S3X 3-speed fixed - who's interested?
« Reply #17 on: August 05, 2009, 03:47:12 pm »
I'm probably missing something obvious, but if set it at 47 at the front then both the S3x and the iMotion would be only 2mm out which is fine. And use a 132 rear end (Cotic?).
Let right or wrong alone decide
God was never on your side.

clarion

  • Tyke
Re: Sturmey-Archer S3X 3-speed fixed - who's interested?
« Reply #18 on: August 05, 2009, 03:51:08 pm »
OK, thanks.  I wasn't sure if the difference in OLN might cause as many problems as the chainline deviation, but I suppose you're right.  2mm deviation acceptable?  I suppose so.  I'm not sure what degree of accuracy I could measure.

I just need to experiment to see what chainset could do me 47mm.

Thank you. :)

PS: Not OT for this thread, as it affects whether I want one or not :)
Getting there...

robbo6

Re: Sturmey-Archer S3X 3-speed fixed - who's interested?
« Reply #19 on: August 05, 2009, 04:21:08 pm »
Or set the outer shoulders of the cranks to give 45 for the s3x and use spacers under the chainwheel for the im9. It's not going to be a 5 minute job to change over anyway, unless you leave both sets of controls and cables in place all the time.

clarion

  • Tyke
Re: Sturmey-Archer S3X 3-speed fixed - who's interested?
« Reply #20 on: August 05, 2009, 04:22:36 pm »
Sounds doable, though...
Getting there...

Re: Sturmey-Archer S3X 3-speed fixed - who's interested?
« Reply #21 on: August 05, 2009, 05:23:15 pm »
Just respace the S3X a bit before building the wheel.  If it's like other modern SA hubs there will be a spacer between the RH locktab washer and locknut, or the locknut itself will be very thick.  Remove spacing from here (or fit an old-style SA locknut which is very thin), move it to under the LH locknut and you have increased the maximum chainline.  Some 1mm thick washers are handy for such fine tuning.

Don't worry about the wheel dish - few SA wheels are truly dishless.
Never tell me the odds.

Re: Sturmey-Archer S3X 3-speed fixed - who's interested?
« Reply #22 on: August 05, 2009, 05:49:48 pm »
Two chainrings with the same tooth count?
The inner and outer would be about 5-8mm apart wouldn't they?

Re: Sturmey-Archer S3X 3-speed fixed - who's interested?
« Reply #23 on: August 05, 2009, 06:49:34 pm »
2mm is neither here nor there - why manufacture complicated answers to a problem that doesn't exist!
Let right or wrong alone decide
God was never on your side.

Re: Sturmey-Archer S3X 3-speed fixed - who's interested?
« Reply #24 on: August 05, 2009, 07:23:01 pm »
Depends what sort of chain you use.  A full-bushing one can crackle like mad with a 2mm difference.
Never tell me the odds.