Cycling UK Forum

Carlton green wrote: ↑31 Mar 2024, 7:37pm It’ll be interesting to see how you get on.

Hmm, I wonder if the frame will give way before I strip the gears?
Odometer is showing 3896 miles at the moment...

Carlton green wrote: ↑31 Mar 2024, 7:37pm

Brik wrote: ↑31 Mar 2024, 5:57pm I'm out on the bike now, just getting used to the new gears.
This picture shows the axle nut interface
17119040141288894007758149752429.jpg

It looks like you’ve got a mid drive motor on that bike? The SA AW has a reputation for robustness, but how much power you can reliably put through them I’m not so sure. It’ll be interesting to see how you get on.

The standard AW crumbles in tandem use. The planet pinions can't take it.

rogerzilla wrote: ↑1 Apr 2024, 7:29pm

Carlton green wrote: ↑31 Mar 2024, 7:37pm

Brik wrote: ↑31 Mar 2024, 5:57pm I'm out on the bike now, just getting used to the new gears.
This picture shows the axle nut interface
17119040141288894007758149752429.jpg

It looks like you’ve got a mid drive motor on that bike? The SA AW has a reputation for robustness, but how much power you can reliably put through them I’m not so sure. It’ll be interesting to see how you get on.

The standard AW crumbles in tandem use. The planet pinions can't take it.

That’s sort of what I suspected. An SA AW will take a lot of abuse but there’s still a limit to what it’ll survive. I don’t suppose there’s any upgrades to help?

Of course the power of two people is put through a tandem hub and so against the resistive loading that two people create. However with an ordinary bike the resisting load is less and an electric motor just adds available power which might not be used.

It’ll be interesting to see how the OP gets on over time.

There was a BMX AW hub (!) but it may only have been the axle that was strengthened. I need to go and google that one.

Carlton green wrote: ↑2 Apr 2024, 1:31pm

rogerzilla wrote: ↑1 Apr 2024, 7:29pm The standard AW crumbles in tandem use. The planet pinions can't take it.

That’s sort of what I suspected. An SA AW will take a lot of abuse but there’s still a limit to what it’ll survive......

BITD an AW hub was quite a popular choice for tandems. If anybody has any relevant experience, do share.

Brucey wrote: ↑6 Apr 2024, 12:13pm

Carlton green wrote: ↑2 Apr 2024, 1:31pm

rogerzilla wrote: ↑1 Apr 2024, 7:29pm The standard AW crumbles in tandem use. The planet pinions can't take it.

That’s sort of what I suspected. An SA AW will take a lot of abuse but there’s still a limit to what it’ll survive......

BITD an AW hub was quite a popular choice for tandems. If anybody has any relevant experience, do share.

Whilst it’d be nice to know (I’d certainly like to) the longevity is a bit of thread drift and hypothetical. A specialist tandem forum might know more about longevity and so might a forum specialising in vintage bikes (restoration of). It may be that the SA three speeds used in older (vintage) tandems predate AW’s in which case their comparability is academic, indeed the OP has a recent AW and it might be either more or less robust than older ones still in circulation, etc. The name on the shell remains the same but where the limits of comparability are I’m not sure, the manufacturer is: a different company; in a different country; and makes a modified (non-original) product.

Edit. By chance I did find that at one point SA did, indeed, sell specific hubs for tandems and those had some enhanced parts. The SA AT and ATC hubs, the later includes a hub brake. There was also an earlier KT series with braked versions.

IIRC the SA 3s hub is one of the few where they don't stipulate a limit on the gearing. They do say not to use it in a tandem, but that clearly didn't,stop anyone BITD.

Brik wrote: ↑1 Apr 2024, 12:11am

Carlton green wrote: ↑31 Mar 2024, 7:37pm It’ll be interesting to see how you get on.

Hmm, I wonder if the frame will give way before I strip the gears?
Odometer is showing 3896 miles at the moment...

...so far so good, touch wood, at 4049 miles.
I would like to add what a joy to use the three speed is, best thing being able to change gear whilst stationary.

Brik wrote: ↑24 Apr 2024, 12:46pm

Brik wrote: ↑1 Apr 2024, 12:11am

Carlton green wrote: ↑31 Mar 2024, 7:37pm It’ll be interesting to see how you get on.

Hmm, I wonder if the frame will give way before I strip the gears?
Odometer is showing 3896 miles at the moment...

...so far so good, touch wood, at 4049 miles.
I would like to add what a joy to use the three speed is, best thing being able to change gear whilst stationary.

Unless I’ve misread the thread you’ve now done about 150 miles with the mid-drive SA over the last few weeks or so. It’s good to hear that it’s not yet broken and I very much hope that it stays that way - my fingers are crossed for your success. As the months and seasons go by, and the miles traveled accumulate, please let us know how you’ve got on.

From a none believer I’ve become a bit of a SA AW zealot who keeps telling everyone how wonderful they are. I rode my SA AW this morning and think them a joy to use.

I first dismantled an AW hub when I was about seven years old. Call me slow if you like, but I have only just worked out what can be done with them, some 50-odd years later.
So I now know exactly how to make a 3s hub lighter, stronger and more efficient. It also looks a hell of a lot better, readily accepts a disc brake, builds into the strongest rear wheel you have ever seen, and I've even worked out a nifty way of connecting as many cogs as you like to the standard driver, and they can be removed with a small screwdriver and spanner. All (hopefully) without doing anything which might threaten the famed reliability.

Brucey wrote: ↑13 Apr 2024, 8:03pm IIRC the SA 3s hub is one of the few where they don't stipulate a limit on the gearing. They do say not to use it in a tandem, but that clearly didn't,stop anyone BITD.

According to Tony Hadland's book "The Sturmey Archer Story", SA made a tandem specific AW right from near the start of production, in the form of the ATC hub. A=A series; T=Tandem; C= cable operation. It was a three speed hub brake.
" The hubs had nickel-chromium sun and planet pinions for extra strength".

thank for that. I have seen a number of tandems using brakeless, apparently standard hubs. Maybe they had upgraded internals, or the shorter life was deemed acceptable, or something. I wonder what the acceptable torque for a standard gear is, exactly?

Brucey wrote: ↑29 Apr 2024, 11:27am I first dismantled an AW hub when I was about seven years old. Call me slow if you like, but I have only just worked out what can be done with them, some 50-odd years later.
So I now know exactly how to make a 3s hub lighter, stronger and more efficient. It also looks a hell of a lot better, readily accepts a disc brake, builds into the strongest rear wheel you have ever seen, and I've even worked out a nifty way of connecting as many cogs as you like to the standard driver, and they can be removed with a small screwdriver and spanner. All (hopefully) without doing anything which might threaten the famed reliability.

It occured to me that one could drill a few holes in a Sturmey sprocket and add several more using spacers and nuts and bolts. Never got around to it, and not sure how many would go in using the standard axle. Maybe 5 max if using 3/32 sprockets. A disc could be bolted on the left side but would entail drilling and tapping the existing shell being careful on assembly that it wouldn't foul on the internals. Any tinkerers here to shed more ideas.

in my conversion, the hub flanges are about 90mm apart and most of the hubshell (by length) is made from Al, not steel.