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


Go Back   > >

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.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 07-01-11, 11:31 PM   #1
jzsoup
Senior Member
Thread Starter
 
Join Date: Oct 2008
Bikes:
Posts: 300
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I picked up a free Motobecane at a garage sale.......

and am wondering if I can replace the old cotter crank and BB with a modern 68mm square taper. Will the threads match up? The frame indicates the bike was made in France so that makes me think it may have some strange/rare size. This will be my first attempt at working with such an old bike and going in blind, so I appreciate the help.
jzsoup is offline   Reply With Quote
Old 07-02-11, 02:17 AM   #2
marley mission
people's champ
 
marley mission's Avatar
 
Join Date: Oct 2010
Location: joisey
Bikes:
Posts: 1,517
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
free motobecane! suhweet! stay cottered - classic look - just use the right tool to remove the pins
marley mission is offline   Reply With Quote
Old 07-02-11, 05:17 AM   #3
mparker326 
Senior Member
 
mparker326's Avatar
 
Join Date: Aug 2006
Location: Knoxville, TN
Bikes: Schwinn Paramount P15, Fisher Montare, Proteus, Rivendell Quickbeam
Posts: 1,970
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
pics?
mparker326 is offline   Reply With Quote
Old 07-02-11, 05:49 AM   #4
wahoonc
Senior Member
 
wahoonc's Avatar
 
Join Date: Jan 2005
Location: On the road-USA
Bikes: Giant Excursion, Raleigh Sports, Raleigh R.S.W. Compact, Motobecane? and about 20 more! OMG
Posts: 16,687
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Yes you can...if you find the correct size bottom bracket cups. I did it way back in 1978. You most likely will have either a Swiss or French threaded BB. FWIW I used Campy cups in mine, because that was what was available at the time.

Aaron
__________________
Webshots is bailing out, if you find any of my posts with corrupt picture files and want to see them corrected please let me know. :(

ISO: A late 1980's Giant Iguana MTB frameset (or complete bike) 23" Red with yellow graphics.

"Cycling should be a way of life, not a hobby.
RIDE, YOU FOOL, RIDE!"
_Nicodemus

"Steel: nearly a thousand years of metallurgical development
Aluminum: barely a hundred
Which one would you rather have under your butt at 30mph?"
_krazygluon
wahoonc is offline   Reply With Quote
Old 07-02-11, 05:50 AM   #5
cycleheimer
Senior Member
 
cycleheimer's Avatar
 
Join Date: Nov 2008
Location: New York Metro Area
Bikes: 2014 Insight 2, 1995 Trek 720 Multi-Track, 1994 Cannondale M600, 1991 Schwinn CrossCut, Raleigh Dash Max, 1981 Fuji S12S (18 spd), 1978 Bridgestone Kabuki Diamond Touring, 1958 Rudge Sports
Posts: 3,515
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
JensonUSA seems to have a good supply of BB cartridges when you're ready to order...

http://www.jensonusa.com/store/sub/1...+Brackets.aspx
cycleheimer is offline   Reply With Quote
Old 07-02-11, 06:13 AM   #6
auchencrow 
Senior Member
 
auchencrow's Avatar
 
Join Date: Apr 2009
Location: Detroit
Bikes:
Posts: 10,330
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Quote:
Originally Posted by marley mission View Post
free motobecane! suhweet! stay cottered - classic look - just use the right tool to remove the pins
+1

Unless there is a problem with the crank, changing to cotterless will degrade the looks and durability of the crank in exchange for a minor weight reduction and some grief/expense in finding a suitable spindle &/cups.

(PS- Pics or it didn't happen!)
__________________
- Auchen
auchencrow is offline   Reply With Quote
Old 07-02-11, 11:55 AM   #7
ScottNotBombs
Senior Member
 
ScottNotBombs's Avatar
 
Join Date: Mar 2008
Location: Joliet, IL
Bikes:
Posts: 405
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
If you decide to upgrade, you may be able find a spindle the right length and just replace that. If you have to buy a bottom bracket and crankset, the cost isn't worth it.
ScottNotBombs is offline   Reply With Quote
Old 07-02-11, 12:29 PM   #8
tolfan
Novist senior member
 
tolfan's Avatar
 
Join Date: Feb 2006
Location: Amish Country
Bikes: have about 30 bikes right now
Posts: 1,519
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I have done this a few times and I always used the cups that came with the bike, never had any problem.
tolfan is offline   Reply With Quote
Old 07-02-11, 12:30 PM   #9
michael k
Senior Member
 
michael k's Avatar
 
Join Date: Sep 2009
Location: Portland,Or
Bikes:
Posts: 1,059
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Iv;e done it twice.

The '75 came with english threading




This HAD swiss threading.Retapped to english.

michael k is offline   Reply With Quote
Old 07-02-11, 01:32 PM   #10
Henry III 
is just a real cool dude
 
Henry III's Avatar
 
Join Date: Aug 2010
Location: The Thumb, MI
Bikes:
Posts: 3,076
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
I don't know what's the hassle with cottered cranks? Loosen up the bolt but leave it on enough to cover up the threads(if you want to save them or sell them) and a few taps with a hammer or mallet. No need to deliver death blows just a few love taps and they always come right out.
Henry III is offline   Reply With Quote
Old 07-02-11, 01:55 PM   #11
Coop500
Mike
 
Coop500's Avatar
 
Join Date: Jun 2004
Location: Acme, PA
Bikes: 1994 Specialized Rockhopper FS, 2002 DK Fury24
Posts: 259
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by marley mission View Post
free motobecane! suhweet! stay cottered - classic look - just use the right tool to remove the pins
Agreed, I'd be happy to just to get one free. There is a nice one for sale locally for $150 and I thought that was good LOL.
Coop500 is offline   Reply With Quote
Old 07-03-11, 11:21 PM   #12
jzsoup
Senior Member
Thread Starter
 
Join Date: Oct 2008
Bikes:
Posts: 300
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
After this discussion now I'm thinking maybe just clean it up as best I can and leave it as original as possible. New chain, cables/housing, brake pads, tires/tubes. The frame has some rust on the stays and rear wheel will need to be replaced, but I just happen to have one that will work. I'll have to check ebay and see if these are worth the fixing.....the frame is too large for me.
jzsoup is offline   Reply With Quote
Old 07-04-11, 05:37 AM   #13
wahoonc
Senior Member
 
wahoonc's Avatar
 
Join Date: Jan 2005
Location: On the road-USA
Bikes: Giant Excursion, Raleigh Sports, Raleigh R.S.W. Compact, Motobecane? and about 20 more! OMG
Posts: 16,687
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Henry III View Post
I don't know what's the hassle with cottered cranks? Loosen up the bolt but leave it on enough to cover up the threads(if you want to save them or sell them) and a few taps with a hammer or mallet. No need to deliver death blows just a few love taps and they always come right out.
You obviously HAVE NOT come across the pseudo welded cotters yet...

I have had to drill a couple out over the years, and that was after trying a cotter press and a large hammer. Not all cotters are going to gently tap out.

Aaron
__________________
Webshots is bailing out, if you find any of my posts with corrupt picture files and want to see them corrected please let me know. :(

ISO: A late 1980's Giant Iguana MTB frameset (or complete bike) 23" Red with yellow graphics.

"Cycling should be a way of life, not a hobby.
RIDE, YOU FOOL, RIDE!"
_Nicodemus

"Steel: nearly a thousand years of metallurgical development
Aluminum: barely a hundred
Which one would you rather have under your butt at 30mph?"
_krazygluon
wahoonc 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 04:53 PM.