There was a previous thread about this, but it must have been archived.

Synopsis: Dynocoaster donated a R20 frame for a build around a Sturmey Archer S2C hub; I volunteered. Dynocaster sent the frameset plus extra bits, I started gathering parts.

Then I got sidetracked building this:


Now back on board with this build. Have gathered pretty much everything I need, just gotta get some time to do the work, including cutting down and rethreading the BB and chopping a bit off the headtube.

Got the wheels built:
Front is SA FD 70mm drum brake, laced 3x with wheelsmith 2.0 stainless spokes, brass nipples, 36h Velocity Aeroheat rims.
Rear is SA S2C 2sp kickback hub with coaster brake, same rim and build as above.
Suckers are stout, to say the least. Happy surprise: flats of the S2C axel seem to play extraordinarily nice with rear dropout width, like it was made for it. New roadblock: fork too narrow, will need to be spread...

If you don't fancy cutting down the bottom bracket and rethreading it, there is always this trick

https://www.bikeforums.net/showthread...=1#post6577540

I did it on my Moulton MK3 (same 26TPI threading as the R20).





The beauty of the solution is it does not change the frame or the threading in it at all.

Full picture set with my slightly modified version of the procedure on my flickr set here

I have two S2C hubs and so far they seem very nice.

Jerry

Interesting stuff! I'm getting a lot of broken image links and am feeling robbed of the pictorial goodness in this post - any chance you could check the image urls? Thanks!

I can see them so I think they are ok. If not follow the flickr link.

Mine varries slightly in I take the flanges off the cups so they can go inside the BB housing to help get the chain line correct. Again this was not my idea I got the idea from another poster tipraider.

Regards

Jerry

Bah--I are bike mechanic with access to toolz. But thanks for the alt advice. Park BB facing tool also chases/threads at the same time, so it is the way I'll go as part of the bb shaving process. If the bb doesn't hold on whatever's left of the threads, I'll go with a VO threadless bb. At 68mm, bb will be correct width for that application.

Front end will be threadless headset mod, like others have done, with BMX seatpost stem.

OK, so most of the bike went together yesterday, a few minor things taken care of this AM, and it is done!

Before:



As received from Dynocoaster who started the previous thread with a query about anyone wanting to build up a S2C R20. Crank was rusty and bent, bb dry and notchy, headset was typical plastic bushing. Seat tube was a bit beat up by the clamp area. Not a mint frame by any means. Perfect for a conversion rather than a restoration.

To make this work, I scoured various R20 projects here and on the R20 forum -- none of what I did is at all revolutionary, most if not all mods have been done by others.

After:











Some detail shots:
Through the stem brake cable routing with wine cork:


Race Face BB -- dusty backroom bikeshop score:


Build went surprisingly easy, just needed a solid day's work to get it all together. BB re-threaded so standard English threads and bb shaved down to 73mm. Now any standard BB will work, but we happened to have that lovely Race Face unit languishing at the shop -- no lip on the right side cup, so there is driveline adjustability there.

Cut the headtube down by 23mm, which turns out to be a bit aggressive, but nothing that can't be solved with some headset spacers. This facilitated install of Ritchey Logic threadless headset upper; kept the stock lower because races were fine and of course the new crown race is too small for the Raleigh standard fork. Added a clamp south of the original quick release for good measure. Steerer extension is a BMX seatpost, upper part is 27.2, with a shim at the stem to fit the 1-1/8 stem.

Seatpost is Kalloy, unremarkable; saddle, stem, and handlebars are all Bontager items... yes, I work in a Trek shop. Brake lever is an old flat lever off a city bike, beat, aluminum, but works on this bike. Crank is Bontrager SS, like you'd find on a Trek Soho S.

Drivetrain is 44 x 17 -- with the S2C hub out back, this gives me gear inches of around 43 and 65, a decent cruising gear and a low gear for hills. Wheels I detailed in a previous post; tires are Schwalbe Marathons.

Had this set up with traditional brake cable routing, but with the headset setup, it's a straight, unobstructed run right from top to bottom, so why not route the front brake cable through the stem/headset/steerer? Yes, I can haz barspinz!

As is, this is more a separable bike than a true folder. But so much fun. I've only tooled around on it for a bit, so a longer ride is soon in order.

Wicked fun build -- thanks, Dynocoaster, for the frame and impetus!

PS: extra parts after the build include the cranks, bb, and upper headset.

Right/drive side crank is bent, chainring rusty. Left side seems straight and has a bit of surface rust, but perfectly usable.

Cotter pins are still good, came out easy, still have the Raleigh "R" acorn nuts in good condition.

BB is servicable... cups actually appear to be in decent condition, although I'd need to check one of them out a bit more carefully, but seem to be smooth and free from pitting. Axle is another story, pitted, will need a new one or use this one knowing it will be rough. I was shocked by how easy the chainrings and cups disassembled, had been girding up for uncooperative and rusty mess which might have doomed the project, but things just disassembled like they were supposed to. +1 for whoever built or rebuilt the bike along the way and the proper prep they must have done.

Headset top plastic bushing seems OK, probably could have run it, but wanted to do the bearing swap; decorative cap has surface rust.

I mention these things because there are a couple small pieces I'm looking for and would love to trade:
- Fork top nut. I have one nut, but not the final one with the lip at the top.
- Quick release lever assembly for the main pivot. What's there is kinda rigged and is a bolt, would rather be able to fold without a tool.

Thanks!

Thats a nice build.

Thanks!

Need *another* bike...?

Very nice build. Glad it worked out for you.

LOL No I think I reached my limit of bikes at this point. Maybe if I can sell a couple... I need to finish my little Peugeot project before I buy anything else because I think if I just get is all done I'll be really happy with it.

Thanks! Sure did work out OK--thanks so much for the frame to get things going. The extras, like the headset with lowers and what was left of the upper assembly was totally a bonus, unexpected and instrumental in things coming together so quick and relatively easy.

OK, next step in the R20 saga: will it fit in a suitcase?

Frame came without the main hinge fixing unit -- the release on to top side of the main hinge. Looks like it broke off and theres a nut on there which acts as a locknut once the fixing bolt is threaded into the bottom part. Actually works very well and keeps the bike together and stiff... but precludes easy folding. There's gotta be spares out there, and I could even get something welded up, but it works fine as is.

In any case, bike was together and I happened to have a Samsonite Oyster suitcase hanging around:



Although a quick search of the Samsonite site does not turn up the Oyster. I imagine the F'Lite would work just as well if not better.

So this is going to fit in there...?



Yep.

Bike disassembled, by case:



Couple notes at this point. No way the folded frame was going in whole, so the frame had to separate. Also, bars had to come free of the frame, so cork came out, brake line fed through steerer tube. And finally, the steerer tube had to come off the bars to fit. Just a tad more disassembly than I wanted to do or counted on.

Here's how it goes in. There's other ways, and I'd probably play around with it a bit before I call it ready for prime time.

1) front frame


2) wheels



3) handlebars/stem, seat/seatpost, misc bits like pedals and steerer


4) rear frame w/ cranks & chain


5) done


R20 x S2C Travel Bike! Yar!

There's other ways to do it. First go was front wheel w/ handlebars and seat first, then the frame with front inserted into rear triangle, then the rear wheel. Fit, but definite bulge from one of the axles. Note: would be much easier with quick release wheels. This way worked out OK, and after futzing around with it for a while, was as far as I was going to take it. A few bulgey places on the case, but everything nicely contained without having to force the case closed... too much.

To get the bike broken down, I used a combo tool with 15mm wrench on one end, and a multi-tool but only the 4 and 5mm allen keys -- only three tools needed to break this sucker down:



Re-assembly was 20 minutes. Yes, I built it in the first place, but this really goes together quick, without much fuss.

To make it work for realz, I'd do some detail stuff like get some tubing to go over the axle ends for protection and bag the axle nuts to save width; make some padded sheets to go in-between the components, probably just leather; and deflate the tires. Add one of those mini- floor-pump hybrids to the bag. Either cut down existing bars or find shorter ones.

After all was said and done, I could probably fit some other stuff in there. A rack, maybe, but definitely some riding apparel and shoes. Maybe not a helmet--that would have to go in other luggage. Or just wear it while traveling...

In any case, I'm totally psyched it fits in a case I already have.