Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  

Go Back   > >

Folding Bikes Discuss the unique features and issues of folding bikes. Also a great place to learn what folding bike will work best for your needs.

Thread Tools Search this Thread
Old 01-09-09, 01:47 AM   #1
Senior Member
Thread Starter
parcoju's Avatar
Join Date: Apr 2008
Posts: 80
Yet Another Raleigh Twenty Bottom Bracket Question

By some stroke of luck, I have become the proud owner of two 1971 creamy-white Raleigh Twenties.

The previous owners obviously did not use them much, as the bikes are in splendid condition. The tires seem to be almost entirely unused, but the hub did need a bit of lubing and the cables did need to be adjusted.

I have decided to keep one in its original condition to bomb around at school, but the other....well, it wasn't as lucky

So I'll cut to the chase.

I have read about so many options for the Raleigh Twenty bottom bracket and have settled on the tried-and-true UN72 + Phil Wood retaining rings.

....Only one problem.

Does anyone know if a 73 x 107 UN72 BB spindle would be long enough for the Raleigh Twenty without any frame modifications? I'm currently attending UCI (U. of California, Irvine, for all the internationals out there), and would not want to spend too much...

If anything, I could still use the cottered cranks; I find their 165 mm length welcome for my 5"3' stature.

p.s. I'm having so much fun with my original set up Raleigh Twenty, I even took it out on a fast-casual ride at our campus, "Irvine Ridazz", chock full of hipsters with fixed gears and I was able to keep up!
Except when it came to uphills! 35lbs of pure metal + 8 lbs of luggage doesn't make for good climbing!
parcoju is offline   Reply With Quote
Old 01-09-09, 04:20 AM   #2
Bicycling Gnome
Join Date: Apr 2006
Location: 55.0N 1.59W
Posts: 1,877
If the bikes are little used and in splendid condition, AND, you like the throw of the cottered cranks, why replace the bottom bracket? Those things were meant to put up with daily use and to last a very long time. If it were mine, I'd check that it had some grease and leave it well alone, unless I was bored and had a lot of time, and then I might be tempted to ride it a bit more.....

I wish I had a really nice example of a twenty. I bought a rotten old beast of an example of a 1969 one that had a bone dry hub, badly repainted frame, chain that was so rusty it wouldn't turn without penetrating fluid and cracked tyres. I put some oil in the hub, lubed the chain, wound the crank by hand about fifty turns, pumped the tyres, jumped on her ragged saddle, and pedalled off into the sunset.

These bikes work pretty well as they are. Raleigh made its name by building bikes that served people who used them as their daily transport in a Britain where most people didn't have a car. OK - by the end of the sixties and early seventies there were plenty of cars, but the bikes retained the same heavy, solid, last a lifetime, functionality as those of the early fifties like my dad's old dark green Raleigh Superbe. I bet the BB was likely the same design as the bikes that went for fifty years.

NB - take no notice of my grumbling. I am turning into an old git.

Last edited by EvilV; 01-09-09 at 07:21 AM.
EvilV is offline   Reply With Quote
Old 01-09-09, 11:12 PM   #3
Join Date: Jan 2009
Location: Ca.
Bikes: SmallWheelOnly
Posts: 279
i've had the same situation and question and someone had replied that he used a 68 x 115 on his R20

i bought several un72 off ebay with diff lenghts mainly 115, 122, and 113 i have not had a chance to use them as i need phil woods bb tool to install.

i've read on some website that they shorten the bb shell by cutting/grinding it off as the shell is around 75~76mm length but if you have a un72 115mm or longer it should work fine w/o cutting

im also in socal let me know when you get it done we could setup an R20 ride were in the SGV area and have 5 R20s in our fleet ready to roll.
Attached Images
File Type: jpg IMG_9091.jpg (85.2 KB, 21 views)

Last edited by EM42; 01-10-09 at 11:43 AM. Reason: add image
EM42 is offline   Reply With Quote
Old 01-12-09, 05:08 PM   #4
Senior Member
gruffydd's Avatar
Join Date: Jan 2008
Posts: 193
Contrary to information and advice on the internet, I had problems with Phil Wood cups and a UN 72 bb. Never could get it tight enough.

I finally had to get the bb shell re-threaded to 24 tpi and use a new model Shimano bb. That was a bit dicey. Personally, I would not cut the shell down in width.

If you can overhaul and make the original bb work, I recommend that. Just my opinion and I am certainly not an expert mechanic. But all the women find me handy.
gruffydd is offline   Reply With Quote
Old 01-12-09, 07:06 PM   #5
Senior Member
Thread Starter
parcoju's Avatar
Join Date: Apr 2008
Posts: 80
EvilV, I'm sorry that your initial experience with Raleigh Twenties was not so heartening! I really have no legitimate reason for changing the bottom bracket except that I love working on bicycles and I certainly enjoy a challenge!

EM42, I'd love to join you for a 20 ride! The SGV is a bit far off from where I hail from though xD

gruffydd, how's the re-threaded bb holding up? I've read some pretty nasty things about the lack of threads and all that, but if all is well, then great!

Now, to the 20.

I find that even though the 165 mm cranks are nice, I would like some shorter cranks. My touring/hybrid set up has 145 mm cranks! I also find that the three speed is a bit too overgeared for the hills in my area.

I also wanted to see if I could reduce the q-factor to an absurdly low amount, if possible.

....But really, these are the reasons why I want to upgrade:
A new 8 speed By Sunrace-Sturmey-Archer with a 325% gear range and no need to respace or file Raleigh 20 dropouts,

and the resurrection of the 3-speed fixed gear hub (!) with a 160% gear range, with, yet again, no need to respace or file the 20 dropouts.

I figured that since I do have two Twenties, I could have my bit of fun upgrading them =]
parcoju is offline   Reply With Quote
Old 01-12-09, 07:17 PM   #6
Senior Member
gruffydd's Avatar
Join Date: Jan 2008
Posts: 193
gruffydd, how's the re-threaded bb holding up?

so far, so good. i don't do centuries or brevets on this bike, so i don't think the threads will be an issue now. if you have two 20's, you will have a great time wrenching, since you like that sort of thing.
gruffydd is offline   Reply With Quote
Old 01-16-09, 08:04 PM   #7
Senior Member
Join Date: Mar 2007
Posts: 5,352
I'd recommend upgrading the original steel wheels to alloy. The bike will ride faster and track much better with them.
NormanF is offline   Reply With Quote
Old 01-16-09, 08:11 PM   #8
Senior Member
badmother's Avatar
Join Date: Nov 2007
Posts: 3,085
The rim on the three speed hub is for sure alloy? No rim to beseen on the first picture.
badmother is offline   Reply With Quote
Old 01-17-09, 12:15 AM   #9
my nice bike is at home
kraftwerk's Avatar
Join Date: Feb 2006
Location: Brooklyn, NY
Bikes: 2011 BMC Race Machine / Colnago ct 1 / 80's Rossin / 90's Merlin/ 70's Raleigh 20/ Swift folder, etc.
Posts: 718
post a photo of the twin twenties.
I say Phill wood and shimano for the b.b. and get a nice new crank
give your cotterless to the first one who asks for it...
kraftwerk is offline   Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

All times are GMT -6. The time now is 04:18 AM.