Sturmey Archer / derailleur combination gears

[porteous]

I've done it again. I had a spare Rudge Pathfinder frame, originally built in about 1967 for a derailleur 4 or 5 speed gear set up.

A couple of weeks ago I found a NOS 1990 AW hub that the vendor was prepared to build into a 27 x 1 1/4 wheel at a very reasonable price. Since I had also just found a threaded SA driver it seemed silly not to build a tourer with combination gears. (At least, it seemed a good idea to me!).


Late 60s Phase III Rudge Pathfinder rebuild with SA/Derailleur combi gearing by CraigWales, on Flickr

It has been surprisingly simple. 3 speed 1/8 chain screw on blocks are still quite widely available and not very expensive at all. ( I did think of hanging on for a cyclo item, but a 2 speed used one just went for £45 on fleabay, so I didn't bother). Almost everything else I needed was lurking in the shed on the "I better get that because they are hard to find now, and it will come in handy" principle. (I have tried explaining this theory to my wife, but with little success.). The trickiest job was disassembling the SA hub to fit a longer axle, but there is so much really good advice available on stripping SA hubs on u-tube that I managed it quite easily ( Except I had to reset the cones twice because I didn't pay attention to the fine detail about setting the drive side cone first or the gears won't work !).


SA AW NOS hub with 3 speed derailleur block by CraigWales, on Flickr


Longer axle installed - 9 gear set up by CraigWales, on Flickr

Another week or two will see it finished and out for a spin, a nice incentive to get back on a bike as the weather improves! Has anyone else tried this? I am not clever enough to work out gear ratios, but, with luck, I should have 9 to play with that are all different .

I'll let you know!

 

[tyred]

I'll be interested to know how this works out as I have often considered having a play with this myself. My threaded sturmey driver is on eof my prized cycling components...

 

[porteous]

I'll let you know. I will put some photos up tomorrow. The cyclo 2 and 3 speed blocks that come up are in both screw on and later bayonet form, but an extraordinary price, so a screw on cheap 3 speed on a pre 1951(?) threaded SA driver seems the way to go (I got two AWs, one a 1951 with threaded driver, a complete spare inner assembly and a 3 speed trigger for £10 on e-bay). I had to change the AW axle to 6 1/4 inch, but a new axle was not very much.

 

[tyred]

Looks good.

 

[porteous]

Now had the bike for a while and in that time done a number of 20 mile rides into Herefordshire. The nine gears available are almost intuitive in use and a vast improvement on 3. I am about to convert my 4 speed hub bike to 12 before the fine weather arrives!

 

[TheDoctor]

Was there ever a better answer to "Why?" than "Because I can!"?
*approves*

 

[raleighnut]

Why stop there, a double or triple crank as well
Sheldon Brown did this , I'd insert a hyperlink here but don't know how to. He got up to 60 gears using a 4 SA. 5 Screw on and a 3 Crank I seem to remember.
Why? dunno, probably cos he could, Be good for bragging though ( eg nah mate this ones a 60 speed)

 

[Owd Fella]

It's all in here -

http://www.classiclightweights.co.uk/hybrid-hd.html

 

[Spokesmann]

Working out what gear you are in, especially with double or triple chainrings would be a drawback for me. Technically very clever, though not something I'd want to use on busy commuter road trips...

 

[Bobtoo]

Why stop there, a double or triple crank as well
Sheldon Brown did this , I'd insert a hyperlink here but don't know how to. He got up to 60 gears using a 4 SA. 5 Screw on and a 3 Crank I seem to remember.
Why? dunno, probably cos he could, Be good for bragging though ( eg nah mate this ones a 60 speed)

This is what you need


How do you progress through the gears on the Rudge?

Edit- I've found a five speed chainset!

 

[TheDoctor]

Combine one of those with a SRAM Dual-drive and 11 speed cassette!
That's 5*3*11 for 165 gears, and a right bugger working out a sequential shift pattern!
That's without getting a schlumpf BB involved for 330 gears. And now it's getting silly...

 

[porteous]

Combine one of those with a SRAM Dual-drive and 11 speed cassette!
That's 5*3*11 for 165 gears, and a right bugger working out a sequential shift pattern!
That's without getting a schlumpf BB involved for 330 gears. And now it's getting silly...

Let's not get silly. I thought in the 60s that 4 gears were a bit posh, and 9 seems more than enough for the UK. Not room for a 5 speed block without fouling the frame and yes, I did think about a double chain ring on the front, but quite like the nice retro alloy 48 tooth that's on now. Anyway the 9 speed works so well that just one more really, really, low gear would be enough, leaving two in hand for weekends.

The nine speed works very well, two of the freewheel cogs are slightly larger than the original and one smaller, giving a few more low gears and a couple of higher then the original 3 speed. I tend to linger in the SA three speed "medium" using the low and high when required, That still leaves me lots of options on hills, and just switching the SA to "low" at the lights gives me one of three gears all suitable for moving off in, without having to move off first..

I have to admit to using this concept before. In the late 60s I drove one of these for a living:


WWB 902J, Foden S50 Tilcon by ronnie.cameron2009, on Flickr

The Amey Roadstone (ARC) version had a four speed conventional gear change on the floor and a second three speed gear box working from a compressed air change lever on the steering column. And yes, that is as complicated as it sounds. We used all 12 gears as routine and changing both gear boxes at once was quite a procedure, involving quadruple de-clutching ( In 3rd on the main box and high on the three speed you had to change the 4 speed UP in sequence to changing the 3 speed DOWN to get what was actually 10th gear. Much easier to do than to explain!

I suspect the low revving characteristics of the wonderful Gardner engines made the gear changes possible. I only once missed a change, on the looooong uphill road on the boundary of the Duke of Bedford's estate. It took about 15 minutes at 4 miles an hour before it got flat enough to change up and gain speed. Embarrassing! If you were in the two mile tailback following I would like to take this opportunity to apologise. Look on the bright side, it was a lovely sunny day.

Anyway, 12 on the bike is quite enough, more would just be showing off.

 

[porteous]

It's all in here -

http://www.classiclightweights.co.uk/hybrid-hd.html

It was Bob Damper's article that got me going along this path.

 

[classic33]

Got a triple on the front, 9-speed block on the rear, mounted on a SA 5-speed alloy hub gear.

 

[rhm]

The classic combination, in my opinion, is to put two cogs on a standard Sturmey Archer driver. If you're running a 4 or 5 speed hub, the cogs should be two teeth apart, so a 20 and 22; if you're running an AW hub, three teeth: so 19 and 22 (for example). This gives a nice group of evenly spaced gears. You can use either 3/32" or 1/8" chain. It helps to grind the shape of the teeth down a bit; take the tips off the teeth of the larger one and thin the tips a bit on a grindstone. If you want to get fancy (recommended!) look at the shape of the teeth on a recent Shimano cassette; see how some of the teeth have a bit of a twist? You can emulate that with the grinder and this will make shifting smoother.

I have two cogs on my 1940's Fothergill, shifting the 1/8" chain with an equally ancient derailleur. This photo shows it with a Resilion derailleur; I ran it this way for a couple years, logging perhaps a thousand miles, but recently changed to an even more archaic TriVelox derailleur. The hub is an AW from 1939.