cudak888 

No such thing as an 8 speed freewheel? I could have sworn that I heard someone say that 8-speeds are available in freewheel form, just not too common. Another legend...

I had considered pointing out a jackshaft drive as an example, but I didn't - technically, so long as you can keep jamming hubs into makeshift dropouts on the frame, you'll wind up with a wholly ridiculous amount of speeds, not to mention a ridiculous bike.

I was attempting to keep things in proportion of the maximum amount of gears someone could possibly mount upon most bicycles with minor modification.

True, if Rohloff made an extended-axle model, a 14+7+4 would be possible, but they don't. I wouldn't care to find out what the stress on that axle would be. Heck, make it a cassette, and stick a Shimano 10-speed cluster on it. 14+10+4. Five-hundred and sixty gears. Enough to bring every boneheaded Craigslister within 560 miles crawling on their hands and knees to purchase it.

-Kurt

P.S.: How many internal gears does the SRAM Dual-Drive setup have? Would probably be easier to base a crazy conversion on that, provided there are 6/6+ internal gears - anything less, and the Sturmey S5 becomes the best base hub for such a project.

SirMike1983 

The more I hear, the more I like the simplicity of an S-A 3 or even a basic old 10 speed.

Sheldon Brown

I didn't say there were no 8-speed freewheels, I said Shimano never made one. Sachs/SRAM 8-speeds were fairly common for a while, but fell out of favor because they resulted in a high rate of axle breakage.

It has a 3-speed hub, you could put a 10 speed cassette on it...

Sheldon "Talk Is Cheap" Brown

imabeliever1

An older friend of mine built this many years ago. Not very practical, but still interesting.
Using a one 3 speed hub as a jackshaft running back to a 3 speed hub wheel.

MnHPVA Guy

I'm happy with simple SA S5s on the 3 bikes I ride the most. And unless you have a small drive wheel, very low gears would probably convert the innards of an AW into guacamole.

But, if I ever succumb to this silliness, I have this little unit.
Shown below a stock AW axle, it moves the hub to the left giving clearance for at least 6 cogs. Probably more since Sheldon got 7 to work on the stock axle. I also have threaded drivers and a new 8 speed Sunrace FW so it would just be a matter of slapping it together. I've been running a quad on our 'bent tandem for about 15 years, so that wouldn't be a problem.

But, 3 x 8 x 4 = 96 = yawn. I'd rather spend the time riding.

BTW IMHO a TA Cyclotouriste is about the last crank I'd choose to make into a quad. Ramped and pinned 2nd and 3rd rings are a BIG help. I just sold a 24-36-48-60 155mm Dotek crankset to a gent in Colorado with a faired recumbent trike. Slow up the mountains, a rocketship down.

I've an NOS Cyclo 3 speed conversion, but the 15-19-23 cogs make for a lot of near duplicates with an AW or S5 so I haven't used it yet. Might be good with the FM I won on Ebay today.

BTW2 I've no experience with FMs. Do any of you know of anything I should watch out for?

IRRC Someone mentioned 2 SA cogs back to back not being a good fit. He must have forgotten the dust cover, because it works just fine. 19-22 splits the gears on an AW perfectly. I used that setup for 3 years, but I much prefer an S5.

Mark "Praying the new SRAM iDrive 9 speed proves relable and efficient" Stonich

cudak888 

Mark, what era SA cogs were you working with? The outer cog I used was from the '50s.

-Kurt

MnHPVA Guy

This would have been about 1980, but I don't know the vintage of the cogs. I just remembered that while the 22-19t Sturmeys fit just fine, the 22t didn't work with a deraileur because of the odd, pointy tooth profile. It would shift OK but the chain would skip over the teeth when pushed hard. I ended up with an 1/8" Shimano 22t with a normal tooth profile.

Anyone have a clue why the 22s were so different from the other SA cogs?

jonwvara 

I'm reviving this old thread because I'd like to try something like this. Kurt, I assume you used 1/8" chain with this setup, since you didn't mention changing out the front chainring/crankset. Correct? And the 1/8 chain passed thorough the rd okay, although it was apparently designed for 3/32 chain?
When the two offset cogs are placed back to back, the spacing between them fortuitously turns out to be allow the chain to drop onto either cog cleanly, but not so wide that it skates around between gears or gets stuck? There's a stroke of luck...
Finally, is there any reason to think this wouldn't work with a wider range in back--something like a 23 and a 19? That would seem to give a usefully wide range of gearing with no duplication, given my 48-tooth chainring.
Jon V.

Sixty Fiver

I built a commuter like this using an SA AW and two Shimano cogs (3/32) and spacers... the rear d was a Shimano 600 attached to a friction shifter. 1/8 chain does not have the same degree of lateral flex as does 3/32 chain so using the Shimano cogs solved this issue and made the chain run smoother on the 3/32 single chain ring.

This gives you 6 completely unique gears and aside from cluttering up the look of my bike, worked marvelously well..

I was pondering doing this on my Phillip's Twenty roadie as it would give me a low range for hillier areas and leave me with a decent high range for the flats as ell as address the chain length issues you get with Twenty's and their rather short dropouts.

With a 16/18 combo in the rear it would have a gear range from 36 to 72 gear inches as opposed to it's stock range of 43-77 with it's 15 tooth cog.

I am going to change the 15 to a 16 today and see how I like that as I have not been having issues with hills but getting that chain tension right is a bit of a pain... the 16 will solve that and give me a 40-72 gear inch range.

Another route is to run a double up front with a deraileur / tensioner as you can then get a wider gearing range than you can get with a double cog set up.

jonwvara 

When you say "Shimano cogs," do you mean the SA-compatible dished cogs made for an internally geared Shimano hub, or cassette cogs with the splines filed down to fit? I've had a single filed-down cassette on my AW, but would not have thought that you could fit two and a spacer or spacers.
Yes, I realize 3/32 chain flexes better and would be more practical with a derailleur, but I don't want to get into changing out the old cottered crankset and chainring made to accept 1/8" chain. I know I could do it if I wanted, but it's my dad's old bike and I'm kind of sentimental about keeping the existing parts--though I don't mind adding some new ones. I've seen the occasional old Raleigh Sports retrofitted with a cotterless crank and it just looks wierd and...well...wrong to me.

Sixty Fiver

I used Shimano 3 speed cogs which fit the SA hub.

I just finished swapping the 15 for a 16 on my Twenty and am going to see how that feels... it solved the chain length issue perfectly and the gearing change is minimal. If I don't need to run a dual I won't as I really do like the clean look of a 3 speed and with a folder, a derailer is just something that would be prone to getting bent / damaged.

Also interesting is that the cottered crank on the Twenty has a chain ring sized for 3/32 chain while the SA cog is 1/8... I guess they used one crank / chain ring for 3 speed and 5 speed bikes.

On my other conversion I fitted a 3 speed drive into a modern Raleigh road bike that already had a 3/32 chain ring and would agree that a modern crank on a vintage bike would look very odd although it is practical.

squirtdad

Very cool, and I totally understand the fun of seeing what can be done with what is on hand and trying different combinations.

But if the goal is to have more speeds, and you are hanging a derailer, thus eliminating the advantage of the low maintenance internal hub, why not put on a wheel with a cassette or free wheel, keep it single up front and get 6 to whatever speeds, with only a single shifter.... Are there advantages, technical problems, style issues I am not seeing? thanks

I made a "japanese 8 speed" by converting an old nishki...it is 1x8 with some nitto bars that are very english 3 speed like. very comfy.

Sixty Fiver

From a aesthetic and functional point of view, not having a derailer on a folder is a good thing.



The gear ratios are 40.3 / 53.7 / 71.6 and I had no trouble doing an in the saddle climb on a 10-12% grade, the middle gear (direct drive) worked against the headwind really well, and the top gear will make the bike fly.

On a conventional bike the derailer would not be as problematic as they don;t fold and have a lot more ground clearance.

If I was to take the bike on long road trips with extended climbs and perhaps more gear (I'm thinking of that), adding another low cog and a derailer would make sense.

jonwvara 

You're right, it's completely a matter of style. If I wanted an efficient rider with more speeds, I'd just ride one of my other bikes. Just the fun of trying to recreate something, I guess. Interesting question, though. Why did anyone ever combine a derailleur with an SA hub, as used to be fairly common practice? Probably because they already had the bike and it was the cheapest way to get to 6 speeds, even if it wasn't mechanically the most efficient. In a way, that's the design challenge I've created for myself: I like this old bike; I'm sentimentally attached to it, and I don't mind introducing some complexity if it means I can ride it comfortably up the monster hills where I live as opposed to hanging it on a hook somewhere.

I still don't know if 1/8" chain will fit through a derailleur. I guess I just have to try it and see what happens.
JV

Sixty Fiver

An SA 3 speed with a dual drive is still a very efficient drive as the hub gears remain efficient and the chain line is going to be pretty straight if you are only changing between two cogs.

Still thinking of a dual drive for my other Twenty as it is my utility bike and I would like to be able to tow my trailer with it and also have gearing suitable for unladen travel.

Getting 1'8 chain through a derailer might be tricky.

jonwvara 

Way long ago, back when snakes had legs and dinosaurs walked the earth, isn't it a fact that people used to use 1/8" chain with derailleurs as a matter of course? As recently as the early 70s, I think you could buy an aftermarket conversion kit to convert English 3 speeds with SA hubs to 6 or 9 speeds. I think the kit included a 2- or 3-cog Cyclo freewheel and a rear derailleur--usually a Huret Allvit. It used the original crankset, so it must have worked with wide chain, no?
Those old Allvit RDs were on all kinds of cheap ten speeds early in the bike boom--my old Raleigh Record had one, and I think the Schwinn Varsities and their clones did as well. The were probably the same mechanism--don't know if they were reconfigured somehow for narrow chain.
It might not be difficult to use some very thin washers to space the halves of ANY derailleur cage out enough to handle wide chain. We're only talking 1/32" total, right? A couple of 1/64" thick washers on each side should do it. If I'm not mistaken, the man Sheldon Brown wrote about doing something like that somewhere in his writings.
So what about the Huret Allvit?
JV

MnHPVA Guy

"Back in the Day" the Cyclos had a derailleur designed for wide chain. To use a Simplex or Huret you had to add washers.

But now single speed 1/8" chains use modern thin plates and nearly flush rivets. At 7.75mm the SRAM PC-1 is narrower than many 20-30 year old derailleur chains.

BTW the slickest RD to use with the typical "2 cogs on an AW" setup is the Huret Svelto. The adjuster screws are plenty long enough to limit travel to 2 cogs. It looks "old timey" enough not to look out of place and it's tiny size makes it almost unobtrusive on a roadster.

Speaking of two cogs on an AW, the 6 speed Brompton folder has just such a setup. Yesterday I rode a prototype Brommie with Titanium fork, seatpost, rear triangle and stem. It had a prototype Sturmey/SunRace 3 speed, made to Brompton's specifications with a much wider jump between gears. Felt like an S5 locked in wide range, but you split the gears with the two cogs.

MnHPVA Guy

I had a dished 16t Shimano cog and a modified pre-Hyperglide 24t cassette cog, with modern 1/8" chain, shifted by a Huret Svelto to widen the range of an FM. Shifted as good as any modern cassette. I'm still using it, but I swapped the 16t for a more useful 18t.

However, I needed a more extreme setup for my wife, who's knee is still recovering from her accident on last May's 3 Speed Tour of Lake Pepin. On her S5 I installed a Shimano dished 22t and a 34t Hyperglide cassette cog. Chain is a 20+ year old 2/32" Sedis and the derailleur is a Huret DupoPar. She needs 3 shifters to get 10 speeds.



Shifting isn't as crisp as the 8 tooth jump, but ain't half bad.

BTW SA/Derailleur hybrids are not allowed on the "3 Speed Tour of Lake Pepin" but she has been granted a special dispensation, as her injury occurred on last year's ride.

sciencemonster

I got in on this late, but here's my 2 cents - I have an 18/23 on my Clubman, along with the Svelto and it works like a dream. I really only need first gear on the 23T, and only for steep hills. But when I need it, boy am I glad it's there. A 22T doesn't work with an 18T, but it works fine with a 19T, which is what I have on my lightened Sports, along with a Cylo 3-speed derailler. It's not as handy as the 23T, but boy, anything more than 22T is REALLY hard to find. I am finding I really like the 19T, too, especially on a windy day.

It ruins the bikes lines, but having that one extra low gear means I can ride the bikes absolutely anywhere.

You have to have the derailler adjusted just right, or the chain overshoots and gets caught between the spokes and the cog and rips your derailer off. Whoops!

I've tried looking into getting a 24T or bigger Shimano cog, but I have no idea how to tell which kind can be adapted for an AW. Can someone point me in the right direction, like with a link? All those cassettes look alike to me.

MnHPVA Guy

Amen! Especially with the medium and close ratio hubs.

With a flat cassette cog and 3/32" chain, the chain clears the spokes and falls harmlessly on the dust cover. Found this out when I 1st installed the DuoPar on Jane's bike and hadn't yet found a longer low gear limiting screw

I've been using Shimano 7 speed cogs as they are a little thicker at 1.85mm. But I want to try some Shimano IG cogs as they are 2.35mm. Avoid the cheapest, painted cogs as they are softer. I have several 7 speed 24s if you need one. mark@bikesmithdesign.com

With a 7 speed cog and one dished one you need a 1mm freewheel/BB spacer between them.



Various dished cogs have differing amounts of offset. The Shimano's work great with flat cassette cogs.

Sixty Fiver

Go to a nut and bolt supply for the longer low limit screws... I can't remember what size and thread they are but bought quite a few for little projects.

If you don't want the extra cable and lever you can always turn the derailer into a manual adjust by inserting a reversed shift cable into the derailer and using the barrel adjuster to set the D. This also works if you happen to snap a shift cable and don't want to be stuck in a high gear when you limp home.

jonwvara 

Thanks for that piece of information and the photo. The past few postings have really brought things into focus.
I love this forum. How did people figure out stuff like this before the internet?
Also, I think that "Svelto" is about the coolest product name of all time.
JV

Sixty Fiver

Went down to the shop today and played with "Grace"... my utility Twenty.

Got the dual drive set up using two Shimano 3 speed cogs (3/32) and no spacers, a pretty vintage Shimano Lark derailer, and a basic Shimano thumbie to handle the shifting.

The only issue is how far I could set the wheel in the dropout with the old Shimano's built in hangar and I will change a few things tomorrow as I have a different hangar and derailer that I can set back farther... the hanger also has to be filed down and thinned a little so that the wheel nut and spindle nut can seat properly.





The other issue with a derailer on a folder with 20 inch wheels is when you have this much fresh snow (which the bike handles really well) ...



The conversion on a standard bike is far more straight forward and I wish I still had the pics I had taken of my old dual drive setup.

bbattle

Bianchi used to sell a bike with a 7-spd nexus hub and a 3 cog cassette. You could shift using only the right hand.

Surly sells Dingles, which may come in handy for some of these projects.

Lamplight

Looks great Kurt! I have a Scwhinn Collegiate with a single,long metal stem shifter that might work, but it probably wouldn't look right with all the British parts.