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