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

Convert EF Schwinn to French Thread BB

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.

Convert EF Schwinn to French Thread BB

Old 01-23-12, 05:26 PM
  #1  
Furyus
Member
Thread Starter
 
Furyus's Avatar
 
Join Date: Jul 2007
Location: Leesburg, Va
Posts: 42

Bikes: 1968 Schwinn Slik Chik, 1983 Miyata 310, 2022 Sunday Model C

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Liked 2 Times in 2 Posts
Convert EF Schwinn to French Thread BB

I have a '74 Schwinn Sprint frame and a 3-piece Nervar crank off of a '73 Schwinn Sports Tourer. I'd like to use the Nervar set up on the Sprint. I can find conversion kits to adapt English thread BB's to the EF frames, but not French threads. Can anyone help?

Thanks.

furyus
Furyus is offline  
Old 01-23-12, 05:31 PM
  #2  
big chainring 
Senior Member
 
Join Date: Sep 2007
Location: Wilmette, IL
Posts: 7,318
Mentioned: 17 Post(s)
Tagged: 0 Thread(s)
Quoted: 746 Post(s)
Liked 718 Times in 347 Posts
If your Nervar crank came off a Sports Tourer its English threaded.
big chainring is offline  
Old 01-23-12, 05:33 PM
  #3  
Furyus
Member
Thread Starter
 
Furyus's Avatar
 
Join Date: Jul 2007
Location: Leesburg, Va
Posts: 42

Bikes: 1968 Schwinn Slik Chik, 1983 Miyata 310, 2022 Sunday Model C

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Liked 2 Times in 2 Posts
Really? It did indeed come off a Sports Tourer. I'm betting there is a thread somewhere showing me how to tell the difference, but what do I look for when attempting the swap?

Thank you.

furyus
Furyus is offline  
Old 01-23-12, 05:53 PM
  #4  
noglider 
aka Tom Reingold
 
noglider's Avatar
 
Join Date: Jan 2009
Location: New York, NY, and High Falls, NY, USA
Posts: 40,691

Bikes: 1962 Rudge Sports, 1971 Raleigh Super Course, 1971 Raleigh Pro Track, 1974 Raleigh International, 1975 Viscount Fixie, 1982 McLean, 1996 Lemond (Ti), 2002 Burley Zydeco tandem

Mentioned: 510 Post(s)
Tagged: 0 Thread(s)
Quoted: 7287 Post(s)
Liked 2,365 Times in 1,382 Posts
The French crank makers provided English threads on their cranks for English and American bikes.
__________________
Tom Reingold, tom@noglider.com
New York City and High Falls, NY
Blogs: The Experienced Cyclist; noglider's ride blog

“When man invented the bicycle he reached the peak of his attainments.” — Elizabeth West, US author

Please email me rather than PM'ing me. Thanks.
noglider is offline  
Old 01-23-12, 06:13 PM
  #5  
Furyus
Member
Thread Starter
 
Furyus's Avatar
 
Join Date: Jul 2007
Location: Leesburg, Va
Posts: 42

Bikes: 1968 Schwinn Slik Chik, 1983 Miyata 310, 2022 Sunday Model C

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Liked 2 Times in 2 Posts
Thanks guys, I appreciate the help.

furyus
Furyus is offline  
Old 01-23-12, 06:21 PM
  #6  
Bianchigirll 
Bianchi Goddess
 
Bianchigirll's Avatar
 
Join Date: Apr 2009
Location: Shady Pines Retirement Fort Wayne, In
Posts: 29,724

Bikes: Too many to list here check my signature.

Mentioned: 191 Post(s)
Tagged: 2 Thread(s)
Quoted: 2912 Post(s)
Liked 2,833 Times in 1,460 Posts
Originally Posted by noglider
The French crank makers provided English threads on their cranks for English and American bikes.
Because even the French thought french threading was a lousy idea
__________________
One morning you wake up, the girl is gone, the bikes are gone, all that's left behind is a pair of old tires and a tube of tubular glue, all squeezed out"

Sugar "Kane" Kowalczyk
Bianchigirll is online now  
Old 01-23-12, 06:52 PM
  #7  
GrayJay
Senior Member
 
GrayJay's Avatar
 
Join Date: Sep 2009
Location: EagleRiver AK
Posts: 1,303
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 27 Post(s)
Likes: 0
Liked 59 Times in 32 Posts
Originally Posted by Bianchigirll
Because even the French thought french threading was a lousy idea
I've always thought that swiss threading makes the most sense of any BB threading, nice even metric sizes and LH/RH thread. If the french and swiss had conspired to push swiss threading, it may well have stuck around longer than either have since.
GrayJay is offline  
Old 01-23-12, 09:30 PM
  #8  
sailorbenjamin
Senior Member
 
sailorbenjamin's Avatar
 
Join Date: Mar 2008
Location: Rhode Island (an obscure suburb of Connecticut)
Posts: 5,703

Bikes: one of each

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Likes: 0
Liked 12 Times in 12 Posts
But in answer to your question, yes, there is a conversion kit. It's about 15 buck as I recall and not too difficult to preform. Pastorbob knows his Schwinns inside and out. Ask him where to get them.
sailorbenjamin is offline  
Old 01-24-12, 07:58 AM
  #9  
ColonelJLloyd 
Senior Member
 
ColonelJLloyd's Avatar
 
Join Date: Dec 2009
Location: Louisville
Posts: 8,382
Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 111 Post(s)
Liked 12 Times in 10 Posts
Originally Posted by sailorbenjamin
But in answer to your question, yes, there is a conversion kit.
Ashtabula to French threading? That was the OP's question.
__________________
Bikes on Flickr
I prefer email to private messages. You can contact me at justinhughes@me.com
ColonelJLloyd is offline  
Old 01-24-12, 08:12 AM
  #10  
Grand Bois
Senior Member
 
Grand Bois's Avatar
 
Join Date: Mar 2005
Location: Pinole, CA, USA
Posts: 17,414
Mentioned: 24 Post(s)
Tagged: 0 Thread(s)
Quoted: 443 Post(s)
Likes: 0
Liked 27 Times in 25 Posts
I'm having trouble making sense of this thread. Why would you want to use a French-threaded bottom bracket with the adaptor? The only French threads you might find on a French crank are the pedal and extractor threads.

Maybe it's just me. It's early.

Last edited by Grand Bois; 01-24-12 at 09:42 AM.
Grand Bois is offline  
Old 01-24-12, 10:15 AM
  #11  
T-Mar
Senior Member
 
Join Date: Nov 2004
Posts: 23,233
Mentioned: 652 Post(s)
Tagged: 1 Thread(s)
Quoted: 4719 Post(s)
Likes: 0
Liked 3,034 Times in 1,874 Posts
Originally Posted by Grand Bois
I'm having trouble making sense of this thread. Why would you want to use a French-threaded bottom bracket with the adaptor? The only French threads you might find on a French crank are the pedal and extractor threads.

Maybe it's just me. It's early.
The OP appears to be a newbie (at least to the forum) and assumed that the bottom bracket for a French crankset would have French theads. He neglected to take into acount the USA origin of the donor frame.
T-Mar is offline  
Old 01-24-12, 11:11 AM
  #12  
Chombi
Senior Member
 
Chombi's Avatar
 
Join Date: Jul 2009
Posts: 11,138

Bikes: 1986 Alan Record Carbonio, 1985 Vitus Plus Carbone 7, 1984 Peugeot PSV, 1972 Line Seeker, 1986(est.) Medici Aerodynamic (Project), 1985(est.) Peugeot PY10FC

Mentioned: 22 Post(s)
Tagged: 0 Thread(s)
Quoted: 150 Post(s)
Likes: 0
Liked 34 Times in 27 Posts
Originally Posted by GrayJay
I've always thought that swiss threading makes the most sense of any BB threading, nice even metric sizes and LH/RH thread. If the french and swiss had conspired to push swiss threading, it may well have stuck around longer than either have since.
I only found Swiss threading weird because it is hard to find good quality BB's with the treading. Everynice NOS BB out there is either English or French and some Italian.. I never really looked into it, but does the threading direction on Swiss BB's avoid the tendency for loosening from rotational loads coming from the bearings against the cups?? Is that why they make more sense than other BB threading to you?

Chombi
Chombi is offline  
Old 01-24-12, 11:35 AM
  #13  
Grand Bois
Senior Member
 
Grand Bois's Avatar
 
Join Date: Mar 2005
Location: Pinole, CA, USA
Posts: 17,414
Mentioned: 24 Post(s)
Tagged: 0 Thread(s)
Quoted: 443 Post(s)
Likes: 0
Liked 27 Times in 25 Posts
Originally Posted by T-Mar
The OP appears to be a newbie (at least to the forum) and assumed that the bottom bracket for a French crankset would have French theads. He neglected to take into acount the USA origin of the donor frame.
It's some of the reponses from the regulars that had me confused.
Grand Bois is offline  
Old 01-24-12, 12:25 PM
  #14  
dddd
Ride, Wrench, Swap, Race
 
dddd's Avatar
 
Join Date: Jan 2010
Location: Northern California
Posts: 9,171

Bikes: Cheltenham-Pedersen racer, Boulder F/S Paris-Roubaix, Varsity racer, '52 Christophe, '62 Continental, '92 Merckx, '75 Limongi, '76 Presto, '72 Gitane SC, '71 Schwinn SS, etc.

Mentioned: 132 Post(s)
Tagged: 0 Thread(s)
Quoted: 1554 Post(s)
Liked 1,274 Times in 846 Posts
I've always kept the Ashtabula cranks and kickstands on my Schwinn road bikes because they look right and never creak or cause trouble. I found that the steel chainrings (even on my '64 Varsity and '62 Continental) are perfectly compatible with 9-speed chain (I used C9).
I did have to search extensively to find a few pair of the rare 1/2"-thread clipless bmx pedals, but now I can put my Supersports, Continental and Varsities up against the local Velo-Peloton and duke it out. I just wish I had an extra set for my '61 2-speed Traveler!

I found my 1980 PX10 to have Swiss threading, but when I first went to replace a bad bottom bracket I was thinking it seemed English because of the LH threading on the drive side.
As I installed a shorter, 113mm JIS bb to work with the (ISO) Stronglight arms, The alloy cups on the UN-71 replacement bb needed force to go past a couple of turns and I had to work both cups in with an 18" wrench, going back and forth a hundred times to cut the metric (Swiss) threads into the alloy English cups.
I was able to get the cups to seat nicely against the cartridge bb, and it should last at least 40k miles or forever, whichever comes first. I can't imagine it loosening from normal use. I had to really push on the cup tool to keep the splines from slipping out of the Shimano cup, but now the cups are fully home and the chainline is perfect for the 7-speed freewheel I'm using.

Originally Posted by Chombi
I only found Swiss threading weird because it is hard to find good quality BB's with the treading. Everynice NOS BB out there is either English or French and some Italian...
Chombi
Originally Posted by GrayJay
I've always thought that swiss threading makes the most sense of any BB threading, nice even metric sizes and LH/RH thread. If the french and swiss had conspired to push swiss threading, it may well have stuck around longer than either have since."

Last edited by dddd; 01-24-12 at 12:34 PM.
dddd is offline  
Old 01-24-12, 12:42 PM
  #15  
Scooper
Decrepit Member
 
Scooper's Avatar
 
Join Date: Aug 2005
Location: Santa Rosa, California
Posts: 10,489

Bikes: Waterford 953 RS-22, several Paramounts

Mentioned: 71 Post(s)
Tagged: 0 Thread(s)
Quoted: 634 Post(s)
Liked 68 Times in 57 Posts
The Sports Tourer has standard 68mm 1.37" x 24TPI English thread BB shell.

The Ashtabula to 3-piece crank adapter sailorbenjamin mentions isn't necessary for a Sports Tourer, but is necessary for the Super Sport which came with a one-piece Ashtabula crank like the EF Sprint (the BB shell on Super Sports is larger than the shell on the Sports Tourer and isn't threaded).

Here's the TruVative BB adapter that converts bikes with Ashtabula BB shells to be compatible with English threaded bottom brackets.



Here's the TruVative adapter installed on my '73 Super Sport.

__________________
- Stan

my bikes

Science doesn't care what you believe.

Last edited by Scooper; 01-24-12 at 03:35 PM. Reason: added photos
Scooper is offline  
Old 01-24-12, 12:54 PM
  #16  
GrayJay
Senior Member
 
GrayJay's Avatar
 
Join Date: Sep 2009
Location: EagleRiver AK
Posts: 1,303
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 27 Post(s)
Likes: 0
Liked 59 Times in 32 Posts
Originally Posted by Chombi
I only found Swiss threading weird because it is hard to find good quality BB's with the treading. Everynice NOS BB out there is either English or French and some Italian.. I never really looked into it, but does the threading direction on Swiss BB's avoid the tendency for loosening from rotational loads coming from the bearings against the cups?? Is that why they make more sense than other BB threading to you?

Chombi
Yes, Swiss BB thread is LH/RH (like english). The NDS is identical to a french cup, the DS is LH threaded. 35x1mm threading just seems like a more rational deminsion than english fractional inch thread for a worldwide product. I suppose that the demise of swiss/french threading demonstated the clout of the US+British marketplace for bikes.

Aparently during the 80's some of the french manufactures did briefly switch to using swiss threading before abandoning it for worldwide compatibility of english.

I suppose if the Italian speaking cantons of Ticino and Grisons in Switzerland ever produced bikes, they would have developed a special LH/RH version of Italian threading.

Last edited by GrayJay; 01-24-12 at 01:04 PM.
GrayJay is offline  
Old 01-24-12, 03:13 PM
  #17  
cycle_maven
Collector of Useless Info
 
Join Date: Aug 2009
Posts: 1,407
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 2 Times in 2 Posts
Originally Posted by Chombi
I only found Swiss threading weird because it is hard to find good quality BB's with the treading. Everynice NOS BB out there is either English or French and some Italian.. I never really looked into it, but does the threading direction on Swiss BB's avoid the tendency for loosening from rotational loads coming from the bearings against the cups?? Is that why they make more sense than other BB threading to you?

Chombi
Not so much the rotational friction force, which is in the direction towards unscrewing the cups. The rotational force is really tiny compared to the precession force, which is in the other direction. That's why you really have to reef down on the fixed cup in French and Italian BB's- the precession really wants to unscrew the drive-side cup. Same thing with the pedals.
cycle_maven is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
fietsbob
Framebuilders
6
09-25-18 10:11 AM
ticwanos
Bicycle Mechanics
4
01-10-13 10:04 AM
Oostal
Classic & Vintage
4
09-15-12 11:07 PM
evilfkngenius
Classic & Vintage
9
12-10-10 02:51 PM
sailorbenjamin
Classic & Vintage
2
05-17-10 06:44 PM

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 -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.