For the Sturmey Archer AW experts in the crowd...
 

I know there is great parts interchangeability between most years of the SA AW hub, but I am wondering specifically if I can substitute a driver from a later hub into an earlier hub: my issue is that the hub I am currently working on (1949) has the type of sprocket that screws onto the driver, and that sprocket is showing hooking of the teeth. Screw on sprockets for AWs are apparently very difficult to obtain, so I thought of using a later driver that accepts the circlip, so I can use readily available sprockets. The driver jaws are shaped differently but the are effectively the same size, and I did a temporary fit and everything seemed OK, but I thought I had better check with the experts.

Yeah, I think it's ok to do that. Or get a longer axle and put a freewheel on it and a derailler.

Fwiw if I'm not mistaken, that's a standard track style setup, so you can find replacements easily enough. Getting them off is another matter. I've not seen an AW like that but I have a 4-speed set up that way.

Sturmey-Archer actually recommended that people with the old threaded drivers replace them with the splined drivers. And yes, AFAIK if you can remove the cog from your threaded driver, a standard track cog should thread onto the driver, so that's another option. *IF* you can get the cog off the threaded driver.

Thanks all - there is a special tool for holding the driver to remove the sprocket, but I already have a collection of regular splined sprockets and a spare driver so I think I'll go the cheap and easy route.

The Hercules hub drivers were threaded too, weren't they?

Ooo, Ooo- those threaded drivers are *valuable*. Yes you can replace them with the three-splined version without issue, but folks use the threaded driver to make home-made 18-speed drivetrains using a freewheel screwed to the threaded driver with a longer axle.

I'm tempted to offer to buy the driver, but it would be yet another thing I don't need.

+1 The driver is interchangeable.

My memory is soft on this, but I think SA phased out the threaded driver in favor of the 3-spline driver in the mid- to late-40s. You are right about getting them unthreaded: They are a bear, though someone here on the forum has some pictures or a tutorial for unthreading a cog from the driver.

Yes indeed. While SA moved to the 3-spline setup, Hercules chose to stay with the threaded drivers. When I rebuilt the A-Type 9 hub on my 1949 Hercules Kestrel I chose to put an incorrect 3-spline driver on the hub to more easily accommodate gearing changes. Since the hub freewheels, the only way I know to remove the threaded driver is to take the driver out, something I don't like to do if it can be avoided.

Heat helps a lot with these endevours.

The process is described in the SA manual linked off of Sheldon Brown (you need to find the oldest version), but essentially there is a special tool that you place the drive jaws over, and you use a chain whip to unthread. Simple in theory; I suspect heat and muscle will prevail. However the warning is that if you don't use the correct tool (or use the tool but too much heat/muscle) you will distort the jaws on the driver.

Removing the cog from a threaded driver is not complicated. You need a chain whip with a 1/8" chain and a piece of steel bar. Put steel bar in vise. Put threaded driver over steel bar so that it doesn't rotate. Use chain whip to undo cog (and a cheater bar will help). Cog is left-hand threaded, iirc, so clockwise to loosen. I learned this process from Sheldon Brown: Sheldon Brown's Bicycle Glossary Ta--To (see "Threaded Driver" in the glossary).

It may not be complicated, but that doesn't mean it's easy. I have a threaded driver whose cog I've been working on for several years without success.

No, it's right hand thread or else it would unthread while pedaling. Track hubs have a left-hand thread lockring to prevent the right hand thread track cog from loosening during back-pedaling, but a lockring isn't needed on a hub with a freewheel mechanism, like the AW.

I actually tried a similar method to that, having soaked it with a rust penetrant/lubricant of some sort for several days, and ended up breaking the chain on the whip. At that point, I gave up. It's still sitting on my workbench. :crash:

That doesn't make sense. It would unscrew with normal riding.

Yeah, wtf do I know, but clearly I'm a lot stronger than JohnDThompson and photogravity as I've removed that cog from the driver.

...and an intellectual power-house, to boot! :thumb:

Or you just didn't pedal as hard to begin with.

The specific Sturmey Archer instructions for removing the threaded cog are found on p. 18 of the 1951 service manual. Though it specifies L. H. Thread for removal of the lock ring on hubs with a splined driver, there is no mention of L. H. Thread for removal of the standard threaded cog.

This is the threaded driver I've been struggling with. As you can see, there's no lockring thread:

http://www.os2.dhs.org/~john/threaded-driver.jpg

That does look like a big challenge! :eek:

Indeed!

Okay I will stipulate that you are stronger than anyone, and that you have removed that cog from that driver. But you did not do it by turning it clockwise.

Just in the last couple minutes I removed the 18t threaded cogs from two drivers just like that. I don't have a chain whip nor a good bench vise, so I improvised. I clamped the cog in a large wooden carpenters clamp, held that on the floor with my feet, and applied the L beam from a bed frame to the slot on the driver. It fought me for a few seconds and then unscrewed.

Counter clockwise. In other words, the driver has a right hand thread. Sorry.

Photos can be posted tomorrow if there is an outcry.

If you haven't done it already...

Shoot some WD40 into it and hit it with a torch.