Go Back  Bike Forums > Bike Forums > Framebuilders
Reload this Page >

criterium geometry?

Notices
Framebuilders Thinking about a custom frame? Lugged vs Fillet Brazed. Different Frame materials? Newvex or Pacenti Lugs? why get a custom Road, Mountain, or Track Frame? Got a question about framebuilding? Lets discuss framebuilding at it's finest.

criterium geometry?

Old 08-27-08, 08:56 AM
  #26  
NoReg
Banned
 
Join Date: Aug 2005
Posts: 5,115
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 2 Times in 1 Post
Reminds me of how alloy spars collapse at dock. The spars rock back and forth with negligible but constant low load, and then one day they just collapse. The thing I read on that said one had to consider light and heavy loads intermitently. And apparently that is a comon testing proceedure, though above my pay grade.
NoReg is offline  
Old 08-27-08, 11:34 AM
  #27  
Road Fan
Senior Member
 
Road Fan's Avatar
 
Join Date: Apr 2005
Location: Ann Arbor, MI
Posts: 15,972

Bikes: 1980 Masi, 1984 Mondonico, 1984 Trek 610, 1980 Woodrup Giro, 2005 Mondonico Futura Leggera ELOS, 1967 PX10E, 1971 Peugeot UO-8

Mentioned: 43 Post(s)
Tagged: 0 Thread(s)
Quoted: 1483 Post(s)
Liked 393 Times in 305 Posts
Originally Posted by DannoXYZ View Post
It's not technically "fatigue" in the metallurgical sense since you never ever really stress a frame close enough to its yield-strength to do work-hardening anyway. I suspect what happens is that the tubing themselves are fine, but you end up with lugs and brass that ends up with microscopic cracks. I've cut apart old steel frames and have found a lot of corrosion in the lugged joint itself where there once was full-contact with brass.

So yeah, old steel frames do get softer from A LOT of empirical evidence. However, HOW that softness develops is arguable and certainly is not metal "fatigue". "Frame fatigue" is a more accurate way to describe it perhaps.
Ok, Danno, this begins to sound like the failure of solder joints after extensive thermal shock cycling. The beryllium copper leads are ductile enough that they will not be stressed, but the solder joint itself can easily be undergoing plastic stress cycles, fatiguing, and cracking after only 25 cycles, if the design is very badly wrong. The circuit has not failed, nor has the part or the wiring board, but the joining was not strong.

Road Fan
Road Fan is offline  
Old 09-01-08, 02:20 AM
  #28  
Timmi
Senior Member
 
Timmi's Avatar
 
Join Date: Jul 2008
Location: M0NTREAL - Canada
Posts: 177

Bikes: Turconi, made by Vanni Losa, and a roster of ever-changing other bikes.

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 17 Post(s)
Liked 4 Times in 4 Posts
Anybody own a vintage Cambio Rino? By any chance one imported from Italy BEFORE Joe Gardin started making them in Toronto and messing them all up?
Timmi is offline  
Old 11-22-21, 01:23 AM
  #29  
Timmi
Senior Member
 
Timmi's Avatar
 
Join Date: Jul 2008
Location: M0NTREAL - Canada
Posts: 177

Bikes: Turconi, made by Vanni Losa, and a roster of ever-changing other bikes.

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 17 Post(s)
Liked 4 Times in 4 Posts
Originally Posted by Road Fan View Post
why hasn't the Golden Gate Bridge fallen down or gone noodly yet? Its materials are really really similar to those in your Vicini-built frame and it's much older. Road Fan
oh boy oh boy, if you think that the golden gate bridge uses the same kind of steel as high-end bicycle tubing,
you've got a long and steep learning curve ahead - the slope of which is accentuated by your stance.
Timmi is offline  
Old 11-22-21, 02:36 AM
  #30  
guy153
Senior Member
 
Join Date: Dec 2019
Posts: 780
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 274 Post(s)
Liked 193 Times in 161 Posts
Originally Posted by Timmi View Post
whatever.

I think there is a discussion forum regarding metallurgy on the internet somewhere... I'm sure...

my post was NOT for that audience... I know where I am, and I don't need a GPS for that!
Yes but facts are facts. They don't care if you call them "metallurgy" or not. They're still true. Your post was good advice but a legitimate quibble was raised: steel frames don't go soft in use.
guy153 is offline  
Likes For guy153:
Old 11-22-21, 07:39 AM
  #31  
Nessism
Senior Member
 
Nessism's Avatar
 
Join Date: Jun 2004
Location: Torrance, CA
Posts: 3,023

Bikes: Homebuilt steel

Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 1772 Post(s)
Liked 342 Times in 273 Posts
I love the return of zombie threads!
Nessism is offline  
Old 11-22-21, 07:41 AM
  #32  
unterhausen
Randomhead
 
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Posts: 22,526
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked 2,088 Times in 1,487 Posts
Half the people that were arguing in this thread are not here to defend themselves and the other half have blissfully forgotten about it in the last 13 years. So I'm closing it.

Materials wars are so 2008.
unterhausen is offline  
Likes For unterhausen:

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 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.