Undoing SA AW ball ring

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fatboy
Posts: 3477
Joined: 5 Jan 2007, 1:32pm
Location: North Hertfordshire

Undoing SA AW ball ring

Post by fatboy »

Just bought a 1978 AW off fleabay so I can see inside but I can't get in as I can't get the RH ballring undone. Any tips?

I took the sprocket off and the LH cone. Then I tried to tap the RH ball ring to loosen it but to no avail. I have tried to run some plus gas into the joint. I have also filled the gear up with 3 in 1 in the hope that some gets to where I need it. Am I missing a trick?
"Marriage is a wonderful invention; but then again so is the bicycle puncture repair kit." - Billy Connolly
Brucey
Posts: 44522
Joined: 4 Jan 2012, 6:25pm

Re: Undoing SA AW ball ring

Post by Brucey »

if it is a bare hub you need to stand on the hub (on a soft surface) and use a ~1/2lb hammer and a suitable drift on the notches. Set the notch at half-past ten and set the punch vertically. Two smart blows on one notch, then turn the hub 180 degrees and go again. If the hub is in a wheel then it is the same procedure but it is easier.

If you use the wrong weight of hammer (too light or too heavy) it won't come undone (esp on a loose hub). Ask me how I know...

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
fatboy
Posts: 3477
Joined: 5 Jan 2007, 1:32pm
Location: North Hertfordshire

Re: Undoing SA AW ball ring

Post by fatboy »

I'll give that a go later. Thanks for the tip.
"Marriage is a wonderful invention; but then again so is the bicycle puncture repair kit." - Billy Connolly
Brucey
Posts: 44522
Joined: 4 Jan 2012, 6:25pm

Re: Undoing SA AW ball ring

Post by Brucey »

BTW if you have a rubber-faced strap wrench it can help on a loose hub, but I've succeeded OK without one many times.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
fatboy
Posts: 3477
Joined: 5 Jan 2007, 1:32pm
Location: North Hertfordshire

Re: Undoing SA AW ball ring

Post by fatboy »

Finally managed. Knackered a nail punch (belonging to my wife. Oooopppss:)) in the process. Needed a lie down after my success!
"Marriage is a wonderful invention; but then again so is the bicycle puncture repair kit." - Billy Connolly
Brucey
Posts: 44522
Joined: 4 Jan 2012, 6:25pm

Re: Undoing SA AW ball ring

Post by Brucey »

I have felt like that before, too. Calling the recalcitrant hub a little so-and-so and chasing it around the garden one blow at a time probably doesn't do any good but it does make you feel better...

My favoured punch is actually a 'pound-through' screwdriver with a reground end.

For some reason I think that it goes easier with a slightly longer punch. I don't know whether this is because the hit is always a bit straighter, or if the punch better stores more elastic energy and therefore gives a better hit to the part.

cheers



cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
fatboy
Posts: 3477
Joined: 5 Jan 2007, 1:32pm
Location: North Hertfordshire

Re: Undoing SA AW ball ring

Post by fatboy »

Spent this afternoon dismantling and cleaning out the rusty sludge that was inside it. Annyhow this hub was perfect for my education. They are a wonderful piece of timeless engineering. I can see why they are hard to break. Very simple but sneaky clever as well (which always appeals to me). I now also can understand how my Sprinter works and can make it change gear better because of this fact.

I would recommend getting a cheap AW and taking it apart (cheap on eBay) for mechanical education processes!
"Marriage is a wonderful invention; but then again so is the bicycle puncture repair kit." - Billy Connolly
Brucey
Posts: 44522
Joined: 4 Jan 2012, 6:25pm

Re: Undoing SA AW ball ring

Post by Brucey »

I endorse this route to IGH knowledge too; it is worth asking at your LBS if they have a scrap hub you can have; they very often will do.

One LBS proprietor to me will (given the chance) point out how it used to be the case that he would service scruffy bikes belonging to quite old men, and discover that the bike in question was the only bike they had ever owned. Whilst the rest of the bike might have had numerous repairs of various kinds, a perfectly functional 3s hub would be commonplace, having had nothing but the occasional drop of oil in the last 50 years or so...

Unfortunately the current AW design isn't quite as strong as that and has a few more moving parts, but (production QA problems aside) I'd still expect to get a couple of decades out of it with minimal spare parts required. Just needs a splodge of lube every now and then through the toggle chain hole.

BTW the most mechanically fraught shifts in a sprinter are the 4-5 and (especially) the 2-1 shift. You need to pedal forwards (for about two turns of the pedals with no force) on these shifts. In addition vs the NIG 3s design, the cutouts in the back of the sprinter's main driver are much shallower; this makes gear 4 adjustment critical; if you pull less than 2.5mm of cable from the gear 4 position and it shifts into 3, then the adjustment isn't quite right, and slippage under load in gear 4 (and consequent driver damage) is quite likely.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
fatboy
Posts: 3477
Joined: 5 Jan 2007, 1:32pm
Location: North Hertfordshire

Re: Undoing SA AW ball ring

Post by fatboy »

The one I had apart was from 78 (I was working from newer instructions that showed caged bearings throughout which meant that I wasn't expecting a load of little ones to go pinging on the floor). The newer NIG structure definitely looks a less durable arrangement. Sad that the US back pedal brake only changed the design from a really robust and simple cross piece to a shaped clutch, some pawels and a bent bit of metal! Can now also see why you've got over 30 years on your twin cable 5 speed and why without gentle treatment a Sprinter would be less likely to make such a ripe age. Ming you probably no great shakes to fix now I know how to get in.

Cheers

Chris
"Marriage is a wonderful invention; but then again so is the bicycle puncture repair kit." - Billy Connolly
Brucey
Posts: 44522
Joined: 4 Jan 2012, 6:25pm

Re: Undoing SA AW ball ring

Post by Brucey »

fatboy wrote:The one I had apart was from 78 (I was working from newer instructions that showed caged bearings throughout which meant that I wasn't expecting a load of little ones to go pinging on the floor).


keeps you on your toes, though... :lol:

The newer NIG structure definitely looks a less durable arrangement. Sad that the US back pedal brake only changed the design from a really robust and simple cross piece to a shaped clutch, some pawels and a bent bit of metal! Can now also see why you've got over 30 years on your twin cable 5 speed and why without gentle treatment a Sprinter would be less likely to make such a ripe age. Ming you probably no great shakes to fix now I know how to get in.

Cheers

Chris


absolutely; once I saw how a sprinter worked inside I knew immediately how to change gear better in that hub, and how (on some shifts) following SA's advice for gear changes might be exactly the worst thing you could do.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
STURMEYADDICT
Posts: 9
Joined: 26 Feb 2009, 10:52pm

Re: Undoing SA AW ball ring

Post by STURMEYADDICT »

In general, I find the best (and least destructive) way to remove any S/A ball ring, especially if alloy shell, is to 'half lace' shell in a rim, i.e. one side only, and apply the necessary force to loosen.
Brucey
Posts: 44522
Joined: 4 Jan 2012, 6:25pm

Re: Undoing SA AW ball ring

Post by Brucey »

as I mentioned upthread, the exact right weight of hammer etc are required to loosen a ball ring on a loose hub; the wrong weight will provide the wrong quality of blow. It might seem like lacing the hub into a wheel helps but unless the lacing is incredibly tight, it doesn't help as much as you might think; the freeing only works on loose hubs (or hubs in wheels with spokes that are not super- tight) because of the MOI of the hub; this is smaller for old alloy hubshells (from the 1950's) but is actually larger for more modern (1980s on) alloy shells, for the very simple reason that they are usually heavier than the steel equivalent.

One of the many genius features of SA hubs is the twin start thread on the ball ring. Without that, it would be almost impossible to free the ball ring using any kind of normal tools.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
fatboy
Posts: 3477
Joined: 5 Jan 2007, 1:32pm
Location: North Hertfordshire

Re: Undoing SA AW ball ring

Post by fatboy »

Brucey wrote:
One of the many genius features of SA hubs is the twin start thread on the ball ring. Without that, it would be almost impossible to free the ball ring using any kind of normal tools.

cheers


Could you explain/expand on this please
"Marriage is a wonderful invention; but then again so is the bicycle puncture repair kit." - Billy Connolly
Brucey
Posts: 44522
Joined: 4 Jan 2012, 6:25pm

Re: Undoing SA AW ball ring

Post by Brucey »

the 'twin start' screw thread on the ball ring is actually two separate threads (of twice the apparent pitch), one nested between the other. In this way a coarse pitch thread can be used, whilst occupying the same space as a fine pitch thread.

It has been my experience that coarse pitch threads will tighten less than fine pitch ones, and that is exactly the case here, and obviously what the designer intended.

However, if you consult some current engineering texts, you will find equations that purport to show that the tension developed in a fastener (at any given torque setting) is not dependant on the thread pitch. This is, of course, obvious nonsense and I don't know why they teach it.

When reassembling the ball ring, there are two ways to screw it on. In theory it shouldn't make any difference which you use, but in practice the two threads are not quite equally spaced, so it does. Many texts insist that you mark the position of the parts before disassembly, so that you know which way to put it back together again. If you forget to do this, it is no problem; just try it both ways, and whichever way the ball ring screws on furthest by hand, that is the correct way.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
hoogerbooger
Posts: 673
Joined: 14 Jun 2009, 11:27am
Location: In Wales

Re: Undoing SA AW ball ring

Post by hoogerbooger »

After a thankless 9 rounds of bashing of my SRF5(W)'s ballring notches.....I sulked for a while......searched online for advice/ tips on how to avoid buying the expensive spanner.......found nothing new....then searched on this forum and found Brucey's advice above.

I followed his advice exactly......which was seemingly little different to that I had tried. Worked 1st bloomin time.

You can't beat experience. Thank you Brucey.
old fangled
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