For my next bike build, hole in the head, I'll be doing some crazy swapping and building up an egregious road bike.
My first R20 is this one, from 1973.

This is the most recent iteration of the '73 R20, with Sturmey RXL-RD5, Sturmey XL-FDD, square taper bottom bracket and Sugino crankset, Bush and Muller lights, RedShift stem, and a Racktime cargo rack. I've become a big fan of Brooks Cambium saddles for commuting, and this bike has a C19. This bike has been described by my coworker at the shop as "overkill". I tend to agree, but it is a great ride. Heavy, but really nice.

My project bike is starting out with this circa 1970 Twenty:


Then turning it into road bike.

The issue is that the new-to-me R20 has a chainguard and "Overkill R20" does not. So I'm planning on moving most of the components from the first bike, to the second, in order to take advantage of the greater "commuterness" of the chainguard. I'll be returning to a cottered chainset for that bike.

Now, the "new" R20 is going to get built in some kind of near-obscene way. As mentioned in my recent post in the Collection Reduction Support/Encouragement/Accountability Thread, I plan on building this in the spirit of AdventureManCO 's Huffente. Taking what is arguably the most heavy duty, and heavy weight (aside from a Worksman) folding bike, then kitting it out with every lightweight component I have access to, with a budget within some semblance of reason enough to remain married.

My brainstorming has led me to a fork in the road; build this with a Sturmey AW or build this with a traditional 2x(n) drivetrain.
I can put a freewheel on the Sturmey (I have a threaded driver in my collection) and either make it 3x2 (with a 16/20 Maeda BMX freewheel) or 3x6.
OR
I can build up a rear wheel using a traditional freewheel hub and run a 6 or 7 speed freewheel, and pair it with a double crankset. I have available to me a pretty much full Suntour Superbe group, with a few duplicate parts. I was going to use this for my Puch Mistral SLX, but that bike build has probably fallen through. I'm sure I'll get to this summer and wish I had completed it. Anyway, I could do the Superbe build or I could go Dura Ace, though the Shimano route would necessitate the purchase of a bunch of parts. There's all sorts of mix-and-match options here. What I WOULD like to do is use this pair of 7410 brifters to pull shift and braking duty on this bike. I could always have the rest of the bike be Suntour Superbe and the shifters be the Shimano units. The only issue with running a double crankset is shifting. I'd need to either clamp on a slotted chunk of steel to use a braze-on front derailleur (my Superbe is a braze-on), actually have one brazed on, or highly modify an existing clamp-on derailleur to fit around the seat tube of the R20.
Another crazy idea is to use the Dura Ace brifters to shift both a Sturmey AW as well as a derailleur, if I could get the cable pull correct for the IGH.
For steering the beast, I'm hoping to find a Scott Drop-In bar, mount it upside-down so I have the same position as riding upright, but without the flexibility of a super long stem.
I prefer building this with 451 rims, not 406, as I want to use some shorter reach calipers. I'm pretty sure my Superbe 4700 set could reach a 451 rim, but would need an ugly drop bolt to get down to a 406.
Finally, I want to reduce the rake on the fork, which I can do at the shop with the stock fork, or it would be awesome to find a 20" version of a nice lugged road fork with a short rake. One of those Colnago Precisa forks would be the ultimate eff-you for this bike but I'm not going to be finding one of those with a super long steerer tube, shortening the legs and having dropouts brazed in. If I could do all of the brazing myself sure, but not at this point in my life.

Anyway, that's my next crazy project, on top of restoring a mid-60s Frejus, and doing an era-correct build on my 1964 Gillot, both of which seem to have stalled recently due to this recent bout with lackafundage and not having the right spoke lengths for either set of wheels.
Any irresponsible build thoughts about the R20 more productive than "throw that in the river" are appreciated!

Phil