mmcc73

I just replaced the 18t cog on my Raleigh Sports with a 22t cog, and have been really happy with the change. That said, sometimes I do miss the high gear I had before.

I'm intrigued by the concept of adding a second cog and a derailleur. It looks like when folks do this, they usually do a 4 tooth difference between cogs - an 18/22 or 20/24 for example. When this approach is used, though, it looks like only one cog/speed combo extends the gear ratio range. The rest fall in the middle of what a single cog offered.

So here's my question: how big of a difference could one get away with between the two cogs? I've seen 3 spline cogs that go down to 13t and up to 26t. According to the gear calculator, if these two cogs were used, there would be no overlap at all between the gear ratios offered by the two cogs. Would a derailleur be able to hop from a 13t to a 26t cog? Is there some other downfall to using such a configuration?

If 13/26 wouldn't work, what would be the biggest split I could get away with?

Velognome 

The jump in gear inches in a 3spd hub is huge, the idea is to split the ratio of the IGH to get some more usable gears. Big jumps in the cog will make for poor shifts.

fietsbob

How about a double chain ring crank instead?

2 pulley spring loaded chain tensioner to take up the extra chain slack when in the smaller chainring .

Bandera

Read this: Hybrid Hub/Derailleur Gears

And this: Sturmey-Archer Heritage :: History

I've been running an AW/Cyclo 3 hybrid conversion on my town bikes for decades.
It is complicated, fiddly and obtuse to use: Perfectly British and suits my requirements.

A 13-26 shift will be more than problematic,"hopping" will be straight out. If I can recall mine is 44T chainring w/ 15-19-22T or some such operated by a '74 NR derailleur. I'd have to go look & count, not today. I offers 41-104GI w/ nice useful steps for plootering about.

-Bandera

fietsbob

had a 3x3x3 27 speed in the early 60's with that kind of Cyclo 3 cog substitute piece.

Velognome 

Ohhh and look whats on sale at ebay


A 1950 Sturmey FM with a Cyclo 2 speed block...but wait, there's more, you get a front wheel too...that's a complete wheelset, a FW hub and a Cyclo 2spd block for only $250.....need a period Huret or Cyclo derailleur to complete the package? PM me and I'll be happy to separate you from the rest of your cash.

No but really, do it right, do with period correct parts, don't expect much and you'll be a greasy fingered happy soul.

Bandera

I really Hate the Period Correct Dance and it's attendant guff, but that's a Sturmey Archer "FM" 4 speed hub, not your garden variety AW 3 speed.

"A rare model, made for club bicycles."

Sheldon Brown: Sturmey-Archer Bicycle Hubs

With the Cyclo kit and hub in good nick some nice kit to have for a discriminating elderly gentleman with a fondness for the obsolete and obtuse.

-Bandera

JohnDThompson 

If you use the old-style dished cogs, you can position them thus: )( and run a derailleur to shift from one to the other.

fietsbob

Fwiw 16t is the smallest S-A dished cog..13,14 & 15 are flat.



there was a wider 2 cog driver on a Sachs hub for Bromptons, Mk3, their first 2 by 3 hub .

to shift between the 2, the 3/32" thick 13 & 15t pair , 3 of the teeth on the 15 t were shortened ..for shift gates..

I've been using just the 15t, alone, on my S-A AW3 for a few years..

zukahn1 

I'm with the others here a 3/4 tooth jumb is the most on rear shift. If you want more than 2X3 igh setup well give you need to start thinking about riding getting a different bike.

mmcc73

That's the perfect summary to the thread. Thanks for the input one and all.

zukahn1 

You just have to learn to appriciate this old school setup for what it is.

Bianchigirll 

You could always swap in a 8 or 11 speed IGH rear wheel.

zukahn1 

I think a nice 8 or 11 speed IGH may be a bit out of the OP's budget range.

Velognome 

reminds me of a favorite episode......

photogravity

I need to watch that show some day...

aussiemusicman

There were numerous regular 5 cog freewheels that I had accumulated from passing closed bike shops (and their broken wheels out for rubbish) on my route returning from college in London. My home local bike shop had some old, available and cheap threaded SA drivers so, why not just screw on a regular MULTI sprocket freewheel? In my experience, the only one you can use is the LARGE spline type (Normandy/Maillard/ others?) because access to the spindle inner nuts is essential and the other freewheels would hide these when screwed on and therefore be captive for ever! It is essential to defeat the freewheeling action of this external block (use fewer spacer shims/washers in the mechanism and screw the outer race to tighten together) and just 4 sprockets to allow access to the spindle. You CAN screw on the last (5th) sprocket but have to use chain wrenches to remove for future servicing. Use the longer spindle and dish the wheel. Why do all this? Because as a teenager, it was a fun challenge! 14-24 has some gearing overlaps with the AW hub but is still usable. With 26-42 front rings the lowest gears are way lower than 1:1 and have a lot of lost motion before drive is taken up. Many years later, it has never given up on me. I use the outer 42 ring most of the time. Cyclocross type bar end levers and the SA trigger to play with!

PatrickZ

Thanks for sharing your experience with hybrid gearing. Pictures would be great! I currently have a Raleigh Sprite with a 46 crankset (for narrow chain) and a 24/28 on a AW hub, shifted by a Svelto derailleur. The Svelto is only supposed to handle a 26T, but it works on my set up. Perhaps only having to shift across two cogs helps. The 24T is a dished F&S from Bikesmith, and I made the 28 from a flat Miche cassette cog and filed off the extra tabs. The think the hyperglide ramps aid with the shifting without having to over shift. I added a single Sturmey spacer between the two cogs. I use an old Shimano friction thumb shifter mounted on the right side next to the Sturmey shifter to enable quick split shifting if desired (though I never do). The old single lever Huret stem shifter would undoubtedly look classier.

aussiemusicman

see images on Flickr Just for fun, I shall be experimenting with very old French dual speed retro-direct, single chain type dating from 1903. This may work on a threaded driver SA hub but the chain clearance will be a massive consideration!
https://www.flickr.com/photos/75644133@N03/8816816059/

autoteacher

Having a child growing up when SBSP was new, WHY would you want that ear bug?

John E

I think the biggest challenge is finding a longer S-A axle. In the late 1960s a neighbor gave me a 12-speed rear wheel (AW with 14-16-18-20 1/8" (not 3/32") cogset), which worked like a champ with an early Campag. Gran Sport and gave me 10 non-redundant gears from 39 to 99 gear-inches with a 40T chainring and 26" wheels. I always wanted to put a regular 5-speed 3/32" freewheel on it, but never got around to trying it, because the 12-speed rig worked so well, despite its clunky 1/8" chain.

I also had a Cyclo 9-speed rear hub, with 13-19-25 cogs, which yields only about 5 non-redundant gears, but a VERY wide range of ratios. I greatly preferred my narrow 12-speed.

puchfinnland

I dont think it was noted but Brompton folders have SA 3 speeds and a small deraileur between their 2 rear cogs, very unique to their bikes, but a study of their cog count might be educational

Ol Danl

I believe I have read, either on some 3 speed thread here, or in the vast info of Sheldon Brown, that to use much less than a 2:1 ratio of chainring to rear sprocket with a Sturmey hub could possibly damage the hub's internals. The 46/28 combination of PatrickZ's Sprite, and some of the other bikes mentioned or shown on the referenced photos would seem to violate that sort of safety rule. So, are these bikes working safely? PatrickZ -- did your bike's hub ever break while using the 28 cog? For that matter, what would break in an AW hub -- pawls, maybe?

crank_addict

Took awhile to get this one sorted and the combination of shift. Had some teething problems at first (no not gears problems but now after getting some miles in, its been a hoot. Lots of fun with great range. I don't have the specs on the IGH to figure all the gear inches but its a Sturmey copy 3 speed. I have the instruction and parts breakdown but nominal on specs. Austrian made by Styria, sold by Sears under the JC Higgins label #50320 . Seems to be a tough hub with some quality pawl and bearings. Using only Triflow as the lubricant, a significant improvement. These hubs can be found with controls for around $30. The cogset is 15 - 20 - 25. Chain ring combination 46 - 52.

Chain is the original Styria with the wide 1/2 x 1/8. I took it up north to a vintage event early August and had some issues early in the ride. I goofed more than a few times and left me honking. My fault. Plus I had some minor mechanical adjustments that needed attention. After finally dialing it in, so far everything seems clickity spot on and robust. As mentioned it took some figuring out and a different thinking in planning shifts. No lag in shifts. One thing to remember is before shifting the internal hub, one does not pedal, unlike shifting the derailleur or switching between chainrings. I'm now quite comfortable with it in using the entire range.

Really enjoying it and if one wants something different, highly suggest trying a conversion. I'm actually thinking of another like set-up but as a springer forked vintage style off-roader and having a larger rear gear.

PatrickZ

So far so good. I don't have a lot of miles on this configuration, but I have taken it up some steep grades. I try to pedal smooth and I don't stand up. I am cautiously optimistic.