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.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 03-03-08, 05:38 AM   #1
tok
Newbie
Thread Starter
 
Join Date: Mar 2008
Bikes:
Posts: 2
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Raleigh 20 upgrade -straight chain line ?

Hi,

Having been inspired by many otheres before me, I'm in the process of upgrading my Raleigh Stowaway (same as folding 20) and am looking for some advice regarding parts.

I am keeping the 3 speed SA hub, which has been re-spoked onto an alloy rim. Now the problem is I am going to replace the BB, crank etc but not sure what axle length and crank size to use in order to retain a straight chain line.

For the BB I'm going to use a cheap 24tpi *** or Kinex (http://www.rhizomes.nl/twenty.html).

If anyone can give advice on BB axle length, crank size etc to match up with the existing SA 3 speed hub to achieve a straight chain line it would be much appreciated.

Rgds
tok
tok is offline   Reply With Quote
Old 03-03-08, 01:46 PM   #2
'72 superbe
Senior Member
 
Join Date: Feb 2007
Location: Minneapolis, MN
Bikes:
Posts: 52
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I built a SA 5 speed wheel up for my Twenty. Just needed to dish the wheel a bit for it all to line up.
'72 superbe is offline   Reply With Quote
Old 03-05-08, 11:07 AM   #3
tok
Newbie
Thread Starter
 
Join Date: Mar 2008
Bikes:
Posts: 2
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
but what BB and chainring

Thanks - but I no longer have the original BB nor crank and am wandering what size BB and what type of crank / chainring others have used to sucessfully aceive a straight chain line with the stock rear SA 3 speed hub.
tok is offline   Reply With Quote
Old 03-05-08, 01:37 PM   #4
LittlePixel
Raleigh20 PugFixie, Merc
 
LittlePixel's Avatar
 
Join Date: Sep 2004
Location: London UK
Bikes: 1982 Raleigh Twenty Hotrod Fixie; 1984 Peugeot Premier Fixie, 2007 Merc Lightweight folder
Posts: 1,994
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
I didn't re-fit my SA 3 but used a SRAM 7 speed on my Twenty; With that setup I got a straight chainline with a Shimano UN72 bb with a 115 or 117mm axle. It's held in with expensive Phil Wood cups but these are about the only option to hold in a modern BB if you don't want to re-thread the BB shell as a twenty has 24tpi threading not 26 (or the other way round I can never remember!)

The good thing about the above setup is you can adjust the chainline at the BB end of things because the Phil Wood rings have no flange so can be threaded right into the shell on both sides. Therefore you can offset the bb in the shell to some extent to get a good line.

My cranks are 172mm Shimano Tiagras and I fluked a pretty good chainline with that, but with my current fixed setup I had to bolt the chainring on the inner side of the crank arm which is a satisfactory hack to get the line straight, even if it doesn't look quite as elegant.

Hope that's some help.
LittlePixel is offline   Reply With Quote
Old 03-06-08, 11:00 PM   #5
thebikeguy
Smiling and Waving
 
thebikeguy's Avatar
 
Join Date: Mar 2007
Location: Merrickville,Canada
Bikes: -
Posts: 364
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Have you seen Sammyboy's thread?He seems to have a handle on what works for the Twenty.
thebikeguy is offline   Reply With Quote
Old 03-07-08, 04:05 AM   #6
Sammyboy
The Legitimiser
 
Sammyboy's Avatar
 
Join Date: Jul 2005
Location: Southampton, UK
Bikes: Gazelle Trim Trophy, EG Bates Track Bike, HR Bates Cantiflex bike, Nigel Dean fixed gear conversion, Raleigh Royal, Falcon Westminster.
Posts: 4,846
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Hehehehe - I know some things, but I've yet to tackle the chainline issue. It's bound to give me some laughs, I reckon. I've got a UN72 and Phil Wood cups too, so I can hack it around a bit, but going from an SA 3 speed to a Nexus 7 means a totally different OLN. We'll see how hard it is!
Sammyboy is offline   Reply With Quote
Reply


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 11:43 PM.