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

Crescent bikes BB threads

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.

Crescent bikes BB threads

Old 03-07-12, 04:13 PM
  #1  
KRhea
Senior Member
Thread Starter
 
Join Date: Mar 2007
Location: Portland, OR
Posts: 571

Bikes: Lots

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Crescent bikes BB threads

A friend has an old Crescent frame she wants me to "bring it back to life" in the coming months. It was her first ever "real" bike and she wants to give it to her daughter as a gift in the next year. The question I have is, before I start to tear it down, what is the bb threading on a Crescent? Is it english/italian or what? I've searched around and haven't found any info that's helpful on something that specific.
It's the classic orange bike with blk/wht checks and 531 tubing.

Any help is greatly appreciated.

Thanks
KRhea
KRhea is offline  
Old 03-07-12, 06:49 PM
  #2  
dddd
Ride, Wrench, Swap, Race
 
dddd's Avatar
 
Join Date: Jan 2010
Location: Northern California
Posts: 6,370

Bikes: Cheltenham-Pederson 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: 66 Post(s)
Tagged: 0 Thread(s)
Quoted: 470 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
It won't be Italian.

If it has right-hand threading on both cups, then it would definitely be French.

If it's got left-hand threading on the drive-side cup, then you can test-fit some old bb cup or cartridge from a Fuji or whatever.
Then, if it (English cup) only goes easily in one or two turns, it means it's Swiss-threaded.

On my Swiss-threaded 1980 PX10, I used care, some lube and an 18" wrench to work an English-threaded, alloy-cupped Shimano UN7* cartridge into it. It took at least ten minutes each side, but the bb shell did carve those BSA alloy cups into Swiss-threaded cups that then torqued down with a good bottoming feel. I had to move the wrench back and forth for each 1/4 turn that I advenced the cup, and had to really hold the wrench so as to prevent a nice new Park spline tool from slipping under the high torque.
I am nearly certain however, that it will be the very last BB work that is ever needed on that bike.
I chose a 113mm spindle to replace the Stronglight 118, thus compensating for the ISO-JIS taper conversion.
A 115mm would have been just as good, oweing to the Stronglight spindle having had a slight rightward offset (which the Shimano cartridge did not) but my preference typically is for a slightly shorter drive-side spindle when possible.
I must admit that the front derailer spring now seems to downshift with noticeably less authority than before, but still getting the job done 99% of the time.

Lastly, one warning: The flange on those Shimano alloy-cup bb's will break off if you torque too heavily after it bottoms "home". Might make removal difficult because it takes about half of the spline's width with it(!), but also leaves you with a fully-adjustable chainline with the flange out of the way.

Last edited by dddd; 03-07-12 at 07:02 PM. Reason: ...
dddd is offline  
Old 03-07-12, 08:16 PM
  #3  
jyl
Senior Member
 
jyl's Avatar
 
Join Date: Aug 2006
Location: Portland OR
Posts: 7,514

Bikes: 61 Bianchi Specialissima 71 Peugeot G50 7? P'geot PX10 74 Raleigh GranSport 75 P'geot UO8 78? Raleigh Team Pro 82 P'geot PSV 86 P'geot PX 91 Bridgestone MB0 92 B'stone XO1 97 Rans VRex 92 Cannondale R1000 94 B'stone MB5 97 Vitus 997

Mentioned: 124 Post(s)
Tagged: 0 Thread(s)
Quoted: 333 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Would you post a pic of it? My dad had an Orange Crescent when I was a boy, I remember it and my rides with him, fondly.

There are also threadless BBs, e.g. Veloorange makes one.
jyl is offline  
Old 03-07-12, 08:20 PM
  #4  
seypat
Senior Member
 
Join Date: Oct 2010
Posts: 3,570
Mentioned: 40 Post(s)
Tagged: 0 Thread(s)
Quoted: 790 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
I have a 72' that is french. I think most if not all of the orange ones are french. BF member javal will know. Hopefully he will check in.
seypat 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

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