J.Higgins 

Hi folks!

I believe this may be the first time I've posted in Folding Bikes forum, so here goes.

I've won a Raleigh Twenty frame on eBay and it is slated to arrive next week. My plan is to supe it up real good. I know all of the idiosyncrasies of the bottom bracket, so I would prefer to hear a lot about wheel and tire combinations, hubs, and particularly, rims. For those of you with a Twenty, what mods have you done to it?

rhenning

Read Sheldon Brown's posts on Twentys at his site. There are large number of ideas put forth there. For what its worth I have 2 Twentys and one Shopper the non folding version of the bike that I got many ideas and solutions to problems at that site. Roger

https://www.sheldonbrown.com/raleigh-twenty.html

Abu Mahendra

what size wheel are you gonna go for?

J.Higgins 

I dunno... 451? I was kind of hoping you guys would guide me a bit. I want a fast wheel/tire combo. Fast but fun.

J.Higgins 

I've read that page so many times I've got eye-burn

being that its been written years ago, I was hoping for some current-day suggestions.

Schwinnsta

Go with 451, with 406 the brake levers become too long. Use alloy rims, originals were steel. The downside of twenties are being English and Raleigh they are on Whitworth standard, they are heavy, and they are somehow larger when folded. The ride is great.

J.Higgins 

I have a pair of the "Folder" version, which are 16" wheels, fun but they just are as "serious" as the Twenty. Any leads for a decent pair of alloy rims? Also, I'm thinking Nexus IGH hub maybe SA 5-spd?? Any thoughts?

rhenning

The thing with Sheldons page is all the things he recommended or encountered still need to be solved. The narrow rear frame, the narrow front fork and so on is still as true now as it was Sheldon wrote much of this more than 20 years ago. There may be more performance stuff available in England than here. Most of my wheels are built using internal gear hubs (mostly SA AWs) and aluminum BMX rims. Generally I use better quality aluminum side pull brakes also. The possiblities are endless. You will not build the best Twenty ever built but by doing it step by step you will build the best one you can build and be proud of. Just because it has been done before doesn't mean you shouldn't continue to do it again tweaking it to be better if you can. Roger

Abu Mahendra

... because it'll avoid the long reach V-brakes. There are a few wheelsets out there. Wheelsport, Faxson, Litepro, Mialo, etc. You can also get Velocity rims, and have the wheel built.

As for 451 tires, there are fewer choices than for 406. You want fast, so you'll want tires on the narrower side, right? If so, there are Maxxis Torch37-451, SchwalbeDurano28-451, PanaracerMinits28-451.

fietsbob

Phil makes whitworth mounting rings, for their BBs Or a VO that does not use the hubshell threads..

you getting custom braze on bits added and a repaint afterwords?

new SA 4 speed is using 3 overdrive gears , 1:1 low , like the 8 speed but simpler & lighter

the 5 is like 2 3 speeds 3rd is the direct gear.








...

J.Higgins 

Thank you for the tire suggestions. I was aware of the Duranos, but not the other two.

I was casually surfing and found a pair of Alexrims R390 20" Rims, Set Of 2, 36 hole, ETRTO 451 NOS on eBay for $20 and snapped them right up. I love Velocity rims, and I have a set for my Troll that I'm building, but the $180 for a pair of Velocity rims vs $20 for a pair of Alex's - well...

J.Higgins 

Right now I leaning toward facing and rethreading the BB to 73mm, and 24TPI. I have the Park BFS-1, and the Park BTS-1, so facing and threading is not a problem. I'll install a proper ISO BB along with some blue loctite. Should this fail - which I doubt that it will - I can always revert to the VO threadless BB.

I like your question about the braze-ons, because I'm considering a few things, actually. First and foremost will be the addition of a couple water bottle bosses. The addition of any cable stops will be dependent upon what I choose for a drive-train, and I'm not there yet. I'm leaning towards the SA, but no decisions yet.

I'm also toying with the idea of ISO disk brake mounting tabs if I can find an IGH that will accept a brake rotor, and if the frame is amiable towards taking on a disk brake. It might not. I'm going to be taking a lot of measurements and doing a lot of mock-ups before any decision is made.

I'd be brazing this stuff on, then painting. I do not have a powder-coating oven, but I'm a decent painter (not a rattle-canner). I would go with the powder, but there are no talented coaters near me. Besides, an old Raleigh deserves a good coat of paint, right?

J.Higgins 

If I can scab some brake bosses onto this frame, then this may be a viable hub setup.

Sturmey-Archer | RX-RK5

Anyone have any suggestions how big of a chainwheel I should run with this?

fietsbob

smallest cog is 17t.... https://www.sturmey-archer.com/files/...-%20RX-RK5.pdf

HSL993 Sprocket 17T – 1/8”, Flat / HSL986 Sprocket 17T – 3/32”, Flat ... because of internal shift mech.. so ..

maybe a 53t? ...62" gear..

fietsbob

a layer of brass melted over the thread can offer a decent base to recut the thead in the current frequency, & shape, but same diameter..

J.Higgins 

Hmmm. What do you think would be the best way to accomplish this? Braze the brass into the threads and then use an expansion reamer?

fietsbob

If you get a good flow, & don't use too much, the brass can just fill the cut threads..

In Art metalworking,/ jewelry making classes, we used several melting point alloys of silver solder,

so the parts you made first , used the higher melting point , then attached them with some with a lower melting point solder,
so the 1st part made, did not come apart while being attached..


at a welding supply I got some 400f low temperature silver solder
that works for stainless steel brake cable ends being planned to be cut there.

cleanliness and fluxing the surface are important considerations..

Thin brass filler wire + a lower melting point metal could help

(& now torches can include flux with the heat, to keep the surface cleaner and brass flow easier and bond better)

J.Higgins 

I've got bronze wire. I'll have to get some low-temp brass.

badmother

That hub is heavy for what you get. If you want 5 gear SA I would look for one of the older SA 5 hubs, you can still get them. Not much heavyer than the 3 speed hubs. I use one on my B with two sprockets so 5x2.

https://www.ebay.com/itm/Sturmey-arc...DXFmCWFbpFicig

They came in 28h and 32h. Not sure about 36h.

I would look at hub brakes on a bike like that. Drum brakes. Got them on some older folders and like them a lot. They look "right" and they are as good as maintenance free. Coaster brakes are great too but Americans are often not used to them.

fietsbob

any how, Rims, tires, have 32 hole Sun CR 18.. 406 rims on my bike friday.. (its a R'off)

J.Higgins 

Thanks, BM, but I need/want to put a disk brake on it.

fietsbob

FWIW,

My Bike Friday Tikit uses 36 hole hub [IGH], and laces them 2 cross to a 24 hole 349 rim, skipping a few holes in the hub, of course..

fietsbob

W/O layer lips dropout, put the disc caliper on the front of the right fork blade , rather than back of the left,

and braking forces will push the axle more into the dropout,, rather than out of it..

J.Higgins 

Hey thats a good idea! I've never thought of doing that before.

Rob_E

If you go with disc brakes, that takes away the main reason (as far as I'm concerned) for using 451 wheels. The greater choices available in the more standard size make it worthwhile, and if you're not trying to figure out the brake issue, you might as well go with more choice. Of course you only need one working rim/tire combination, so if you have something you like in 451, you're good to go.

I destroyed my Twenty. I mean in the end I literally destroyed it through an accident, but leading up to that, I subjected that bike to all kinds of abuse. Used a hacksaw to trim the bottom bracket enough to get a Velo Orange, threadless bottom bracket in there. Cold set the rear fork to get a 135 OLD hub in there. Bike came disassembled and without the complete headset, so had to make a modern headset work as well. I just made a list the other day:

• Used a hacksaw and file to trim the bottom bracket to a more standard width, so I could put in a cartridge bottom bracket and modern cranks/pedals
• Replaced the front fork
• Used a quill extender to make the steerer tube long enough to attach my trekking bars
• Modern headset -- that was a weird set up, but I can't remember how I managed it.
• New wheels with aluminum rims
• Cold set the dropouts to accommodate a modern gear hub
• Added a Nuvinci hub to give me a decent range without having to figure out a front shifting solution
• Filed out the dropouts to accommodate a wider axle

Did not really figure out the rear brakes. I found a set that had enough reach, but they were cheap and stiff, and when I got them installed, I found that the necessarily weird cable routings made it so hard to pull the brake lever that I ended up just riding with a front brake only. Never got around to addressing that shortcoming. I never wanted to go with 451 wheels because I wanted it to be as compact as possible for fitting in an airline-legal suitcase.

Photos and other details here: https://www.bikeforums.net/20186357-post30.html

Enjoy your bike!