Fitting modern SA hub to old English 3-speed
 

I've acquired an old (probably early 50s) Raleigh Sports/Superbe frame, which I'm planning on fitting a new wheel incorporating a modern SA hub. I know that I'll have to spread the dropouts a little to accommodate the slightly wider OLD, but do I need to file the slots?

The slots are currently around 8mm, and SA lists the new hubs as being "13/32 slotted", which I think is 10.3mm. But is that the measurement across the flats, or including the threads?

So in summary, what size must the dropout slots be for a modern SA hub?

I know I should wait for the wheel to arrive, but I'm impatient and want to start filing now so it's all done in advance :)

Sturmey Archer was a subsidiary of Raleigh during that time period, so Raleigh Sports/Superbes were made specifically to fit SA hubs. Notice that the axle is made with milled flats, these fit matching dropouts in the Sports/Superbe. Sturmey Archer has maintained a remarkable continuity, one can get direct replacements for parts separated by 60+ years. The upshot is that yes, modern hubs will fit into the dropouts exactly without filing, as originally designed.

That 10.3mm(13/32") axle diameter is for the SA specific axle nuts. The 8mm (5/16") is the distance across the flats.

The only time you have to do filing to the dropouts is when fitting a non SA hub that has an axle that is either not 5/16" in diameter, nor has flats of that diameter.

Are you putting in an new production AW or an SRF3 hub? Those still come in 114mm OLD, and those models listed as having larger OLD merely have a longer axle that is spaced out.

Wow, sounds like I might not need to file out the slots at all then!

I'm fitting an X-RD3 hub (classic 3-speed ratio, but with hub brake):
http://www.sturmey-archer.com/produc.../id/14/specs/1

That's apparently got an over-locknut dimension 117 mm.

Yes, that's not an issue, it's the axle diameter I was concerned with.

Question: is the AB-3 not available in Belgium? The AB3 seems to be more classic looking than the XRD-3, it was a factory optional hub during the late 40s and early 50s.

If you're fitting a drum brake in the back, what about the front? The front dropouts are spaced for both narrow ~8mm (5/16") axles and hub width (~90mm). The BF hub has slotted axles, and can be spaced down to the ~90mm fork spacing. Like the AB3, it was a factory option available in the 40s and 50s.

The other front drum brake hubs, especially the dynamo/drum brake combined hubs are spaced to 100mm and have 9mm axles, in order to fit them, the fork has to be spread and the dropouts filed (if you are going with this, file on one side only, to keep things aligned.)

I'm sure it's available in the UK (where my wheels are being built). I went with the XRD-3 as it's the same price and alloy (lighter, and the rim it'll be fitted to is also alloy).

I'm building a path-racer style bike, so I'm not really concerned with it being 100% period correct, more interested in saving a bit of weight here and there.

For the front, I've ordered an X-FD. Again, it's an alloy hub to match the alloy rim. The BF is also available I think.

I've already spread the frame/forks to accommodate the new hubs, and I've filed the bottom of the front dropouts for the slightly wider axle. However, if you really think I've made a mistake, I have another frame (see my recent post about lugwork) which I haven't touched yet, so I could still change things around. I think they're building the wheels tomorrow though, so I'll have to be quick :)

What do you think?

I'm guessing the one you're modifying is the 1946 Raleigh you've mentioned in your sig as 'plan to modernize', if that was the original plan, by all means continue.

The 1949 is mentioned as been planned to 'keep original'. If you plan on making a similar upgrade to drum brakes to the '49 Raleigh, then the AB3 and the BF will be period appropriate (as previously mentioned, similar to a factory upgrade of that period), they'll drop right into the bike with minimal modification to the hubs.

These new hubs are all 36 hole drilling, in contrast to the 32/40 hole drilling of the old Sturmey Archer hubs. Steel or Aluminium Raleigh pattern rims (on the theory of keeping as original appearance as possible) in the 36h drilling for 26 x 1 3/8 are either going to be an ebay.uk hunt or a hunt through Dutch bicycle shops. In Europe, I believe that Rigida makes these rims, mostly for the Dutch market.

Nope, that's another project.

This is just a frame I picked up recently. The '49 is staying completely original, warts and all. I should update my sig really, but Mrs Nerdy might spot it ;)

This early 50s frame I think I'll stick to my original plan to keep it relatively light.