Go Back  Bike Forums > Bike Forums > Classic & Vintage
Reload this Page >

Advice: convert 1975 Raleigh Sports 3sp cotterless crank conversion?

Notices
Classic & Vintage This forum is to discuss the many aspects of classic and vintage bicycles, including musclebikes, lightweights, middleweights, hi-wheelers, bone-shakers, safety bikes and much more.

Advice: convert 1975 Raleigh Sports 3sp cotterless crank conversion?

Old 07-05-20, 05:07 PM
  #1  
mc510
Senior Member
Thread Starter
 
Join Date: Sep 2004
Posts: 55
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 18 Post(s)
Likes: 0
Liked 2 Times in 2 Posts
Advice: convert 1975 Raleigh Sports 3sp cotterless crank?

I've read all of Sheldon Brown's stuff on this conversion; if I understand correctly the route for my 71mm bottom bracket is to keep the original bearing cups and swap in a 5-series or 7-series JIS spindle with 6mm bearings (unless some new cartridge options have appeared since Sheldon wrote those pages?). Lots of old bikes pass through out local bike free swap bin, so maybe I can find one there, or at one of the local bike repair clubs. But I don't quite understand what JIS spindle I'm looking for ... it appears that 5-series JIS spindles ran from 116mm long up to 134mm ... seems like they all have the same distance between the two bearing surfaces, but different lengths for left and right. Are there some particular spindles that are known to work well/not well? And what's a good clue that bike might have a JIS spindle in the bottom bracket? Probably a Japanese made 10 speed from, what, the 1980s? Or is it any Japanese made road bike that doesn't have a cartridge?
mc510 is offline  
Old 07-05-20, 06:34 PM
  #2  
Narhay
Senior Member
 
Narhay's Avatar
 
Join Date: Sep 2012
Location: Toronto, ON, Canada
Posts: 3,225
Mentioned: 95 Post(s)
Tagged: 0 Thread(s)
Quoted: 746 Post(s)
Likes: 0
Liked 185 Times in 125 Posts
The 5 and 7 series are identified for the bottom bracket shell width but the overall length will depend on which crank you select. Some need longer spindles than others.
Narhay is offline  
Likes For Narhay:
Old 07-05-20, 07:45 PM
  #3  
juvela
Senior Member
 
juvela's Avatar
 
Join Date: Feb 2013
Location: Alta California
Posts: 9,504
Mentioned: 265 Post(s)
Tagged: 1 Thread(s)
Quoted: 2117 Post(s)
Liked 334 Times in 295 Posts
-----

your post does not say if you wish to stay with the stock planetary gearing or convert to derailleur gearing

for derailleur gearing you would need to decide if you wanted to go with single plateau or multi plateau drive

the most common nutted spindle ("Type II") for the single plateau conversion you describe would be the 5N

for a two plateau arrangement the most common woud be the 5S

readers would be able to assist you a bit better if you could give some additional information

-----
juvela is offline  
Old 07-05-20, 08:52 PM
  #4  
branko_76 
Senior Member
 
branko_76's Avatar
 
Join Date: Jun 2018
Location: The Urban Shores Of Michigami
Posts: 1,066

Bikes: ........................................ .....Holdsworth "Special"..... .......Falcon "Special".......... .....Raleigh "Super GP"...... ........................................

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 403 Post(s)
Liked 288 Times in 196 Posts
mc510 , what's wrong with the original crank?
branko_76 is offline  
Old 07-05-20, 09:15 PM
  #5  
jackbombay
Senior Member
 
Join Date: Jun 2019
Location: Eastern Idaho
Posts: 781
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 364 Post(s)
Liked 329 Times in 196 Posts
I've done this on several Raleigh/Hercules 3 speeds, the BB shell is 71mm, my buddy turned one down to 68mm for me with the proper park facing tools. For another I had a Ti cartridge BB that didn't have flanges on the threaded portions of the BB so I could just screw them in far enough to clamp the Cartridge BB and they are a bit inset, I did also use a JIS MTB spindle on my ex wife's conversion, and did not face that BB shell to get it to 68mm, I have no idea what spindle it is though :-/ BUT with every Raleigh I have converted to a square taper crank I have always had to have the cog as far outboard as possible to get good chain line, so I am confident when I say that you want the shortest overall length spindle you can get.

As for the threads, the BB shell is 26TPI and anything square taper is 24 TPI, I have some old steel cups that I cut notches into the threads of and I screw them in and out of the BB shell repeatedly and it works quite well, I actually use a large drill to run my "taps" in and out repeatedly.
jackbombay is offline  
Old 07-05-20, 09:17 PM
  #6  
jackbombay
Senior Member
 
Join Date: Jun 2019
Location: Eastern Idaho
Posts: 781
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 364 Post(s)
Liked 329 Times in 196 Posts
Originally Posted by branko_76 View Post
mc510 , what's wrong with the original crank?
Resto mod Raleigh are just so sweet!

650b, centerpull brakes, Campy crank, aluminum bar and stem, this bike is such a sweet townie!

jackbombay is offline  
Likes For jackbombay:
Old 07-05-20, 09:26 PM
  #7  
branko_76 
Senior Member
 
branko_76's Avatar
 
Join Date: Jun 2018
Location: The Urban Shores Of Michigami
Posts: 1,066

Bikes: ........................................ .....Holdsworth "Special"..... .......Falcon "Special".......... .....Raleigh "Super GP"...... ........................................

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 403 Post(s)
Liked 288 Times in 196 Posts
It's a nice frame jackbombay , the alloy components no doubt make the bike lighter but it's hard to beat those old chrome heron head cranks for looks...
branko_76 is offline  
Old 07-05-20, 10:10 PM
  #8  
mc510
Senior Member
Thread Starter
 
Join Date: Sep 2004
Posts: 55
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 18 Post(s)
Likes: 0
Liked 2 Times in 2 Posts
Originally Posted by branko_76 View Post
mc510 , what's wrong with the original crank?
Mainly the impossibility of finding decent cotters and the difficulty of adequately fitting the shoddy ones that I'm able to get. Makes me reluctant to properly maintain the bottom bracket.
Originally Posted by juvela View Post
your post does not say if you wish to stay with the stock planetary gearing or convert to derailleur gearing
I'm intending to stick with the existing Sturmey Archer AW3 hub; I love that thing!

jackbombay that's a beauty! Mine is a disaster of a beater; I've given up on the idea of restoring it but it's still my favorite bike that I've ever had and want to get it in better running shape for my kid to use. Basically just this crank switcheroo and better brakes.)

Last edited by mc510; 07-05-20 at 10:15 PM.
mc510 is offline  
Likes For mc510:
Old 07-05-20, 10:37 PM
  #9  
3alarmer
Friendship is Magic
 
3alarmer's Avatar
 
Join Date: Nov 2010
Location: The Big Tomato
Posts: 18,781

Bikes: old ones

Mentioned: 258 Post(s)
Tagged: 0 Thread(s)
Quoted: 18027 Post(s)
Liked 1,683 Times in 1,232 Posts
.
...the only people I know of who make a BB unit in proprietary Raleigh 26 tpi threading are the ones at Phil Wood, which is pretty expensive for a three speed conversion.
I have heard from multiple sources that people re-tap these to standard 24 tpi all the time without any problems down the road, but I try not to do stuff like that myself.

If you decide to go that route, the Shimano units marked for 68 mm shells will work, you just have to tighten the lipless, non drive side cup in a little farther, to lock the cartridge in place. Not hard to do.

You might have to fiddle around a little bit figuring out what spindle length you need, depending on you crank you pick. the problem with the method you read about using a replacement spindle with your present cups is that those spindles can be hard to find these days. It used to be an easy swap when there were more of them around in the parts stream.
3alarmer is online now  
Old 07-05-20, 10:49 PM
  #10  
jackbombay
Senior Member
 
Join Date: Jun 2019
Location: Eastern Idaho
Posts: 781
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 364 Post(s)
Liked 329 Times in 196 Posts
Originally Posted by branko_76 View Post
It's a nice frame jackbombay , the alloy components no doubt make the bike lighter but it's hard to beat those old chrome heron head cranks for looks...
I love chrome cottered cranks too!

I have a super course with them, not a Heron head chainring of course, but, I like/appreciate most anything bicycle related and I do take my resto modded 3 speeds on 50-100 mile rides which makes for a nice day, but to put down a century on a stock Raleigh sports is somewhat less appealing to me, primarily due to the steel rims, but the overall weight is also unappealing.
jackbombay is offline  
Likes For jackbombay:
Old 07-05-20, 11:00 PM
  #11  
cudak888 
www.theheadbadge.com
 
cudak888's Avatar
 
Join Date: Sep 2005
Location: Southern Florida
Posts: 25,206

Bikes: https://www.theheadbadge.com

Mentioned: 52 Post(s)
Tagged: 0 Thread(s)
Quoted: 986 Post(s)
Liked 813 Times in 526 Posts
This one has been tapped to 24tpi right over the 26tpi threads. I've installed a Shimano UN55 in it with no issues. Unfortunately, I can't say anything about longevity, as I'm still hemming and hawing about getting "just the right" crankset onto this thing.



I'm really tempted just to use Raleigh's current square-taper Heron crankset, but I can't find anyone selling 'em.

-Kurt
__________________







cudak888 is offline  
Old 07-05-20, 11:08 PM
  #12  
jackbombay
Senior Member
 
Join Date: Jun 2019
Location: Eastern Idaho
Posts: 781
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 364 Post(s)
Liked 329 Times in 196 Posts
Originally Posted by cudak888 View Post
This one has been tapped to 24tpi right over the 26tpi threads.
-Kurt


The outer 4-5 threads don't even get touched by the tap, I have zero qualms about retapping Raleigh BB shells!
jackbombay is offline  
Likes For jackbombay:
Old 07-05-20, 11:21 PM
  #13  
branko_76 
Senior Member
 
branko_76's Avatar
 
Join Date: Jun 2018
Location: The Urban Shores Of Michigami
Posts: 1,066

Bikes: ........................................ .....Holdsworth "Special"..... .......Falcon "Special".......... .....Raleigh "Super GP"...... ........................................

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 403 Post(s)
Liked 288 Times in 196 Posts
Originally Posted by mc510 View Post
Mainly the impossibility of finding decent cotters and the difficulty of adequately fitting the shoddy ones that I'm able to get. Makes me reluctant to properly maintain the bottom bracket.
Bikesmith Design & Fabrication is a great resource for cottered crank parts and tools...

BikeSmith Design and Fabrication
branko_76 is offline  
Old 07-06-20, 09:10 AM
  #14  
mc510
Senior Member
Thread Starter
 
Join Date: Sep 2004
Posts: 55
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 18 Post(s)
Likes: 0
Liked 2 Times in 2 Posts
Originally Posted by branko_76 View Post
Bikesmith Design & Fabrication is a great resource for cottered crank parts and tools...
BikeSmith Design and Fabrication
Oh yeah, I remember seeing these last time I went searching for cotters. If I can't find an easy and affordable way to switch to cotterless, I'll go with the BikeSmith fallback.
mc510 is offline  
Old 07-06-20, 09:15 AM
  #15  
mc510
Senior Member
Thread Starter
 
Join Date: Sep 2004
Posts: 55
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 18 Post(s)
Likes: 0
Liked 2 Times in 2 Posts
Originally Posted by jackbombay View Post
As for the threads, the BB shell is 26TPI and anything square taper is 24 TPI, I have some old steel cups that I cut notches into the threads of and I screw them in and out of the BB shell repeatedly and it works quite well, I actually use a large drill to run my "taps" in and out repeatedly.
jackbombay I missed what you were saying here the first time I read it. So you use an old 24tpi cup as a die to recut the threads? I'd have assumed that would just result in destroying the threads on both the cup and the BB, but interesting to hear that it's worked reliably for you. Could you post a picture of your thread cutting cup?
mc510 is offline  
Old 07-06-20, 09:41 AM
  #16  
jackbombay
Senior Member
 
Join Date: Jun 2019
Location: Eastern Idaho
Posts: 781
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 364 Post(s)
Liked 329 Times in 196 Posts
Originally Posted by mc510 View Post
jackbombay I missed what you were saying here the first time I read it. So you use an old 24tpi cup as a die to recut the threads? I'd have assumed that would just result in destroying the threads on both the cup and the BB, but interesting to hear that it's worked reliably for you. Could you post a picture of your thread cutting cup?
The Raleigh BB shell steel is not very hard, the BB Cups cut the threads just fine. I made 6 groves in the cups, paying particular attention to keeping the cutting edge perpendicular to the threads like a proper tap.

Fixed cup side, I ground off the flange so it can screw in and out further,



And a bolt that I welded to it so I can spin it in and out with a drill repeatedly,



Adjustable cup,



Adjustable cup already had a big hex on it so no need to weld a bolt to it,



I rarely use these, I'll gladly tune up the "cutting edges" and mail them to you to use if you like, but you have to return them!!!!
jackbombay is offline  
Old 07-06-20, 12:27 PM
  #17  
thumpism 
Bikes are okay, I guess.
 
thumpism's Avatar
 
Join Date: Jan 2015
Location: Richmond, Virginia
Posts: 5,998

Bikes: Waterford Paramount Touring, Trek 510 city build, Giant CFM-2, Raleigh Sports 3-speeds in M23 & L23, Schwinn Cimarron oddball build, Marin Palisades Trail dropbar conversion, Nishiki Cresta GT

Mentioned: 48 Post(s)
Tagged: 0 Thread(s)
Quoted: 1728 Post(s)
Likes: 0
Liked 457 Times in 324 Posts
I have also tapped a 26TPI Raleigh frame to 24TPI, but not on my own Sportses. I just figure I'll use the Raleigh cups unless something suggests otherwise but those projects are down the road. The cotters work fine for now but if I ever decide to lighten the bike that crank will have to go.
thumpism is offline  
Old 07-06-20, 02:03 PM
  #18  
mc510
Senior Member
Thread Starter
 
Join Date: Sep 2004
Posts: 55
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 18 Post(s)
Likes: 0
Liked 2 Times in 2 Posts
Originally Posted by jackbombay View Post
I rarely use these, I'll gladly tune up the "cutting edges" and mail them to you to use if you like, but you have to return them!!!!
jackbombay , that's incredibly generous; thank you. I'll try not to inconvenience you, though; first effort will be to find an appropriate JIS spindle, if not then I'll need to decide which direction to go.
mc510 is offline  
Old 07-06-20, 02:37 PM
  #19  
jackbombay
Senior Member
 
Join Date: Jun 2019
Location: Eastern Idaho
Posts: 781
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 364 Post(s)
Liked 329 Times in 196 Posts
Originally Posted by mc510 View Post
jackbombay , that's incredibly generous; thank you. I'll try not to inconvenience you, though; first effort will be to find an appropriate JIS spindle, if not then I'll need to decide which direction to go.
Not an inconvenience at all, I ship products from the post office 3-4 days a week anyway :-)

If your cups are in good shape getting a spindle of the correct length is a great way to go too!
jackbombay is offline  

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


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.