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


Go Back   > >

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.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 11-14-09, 10:07 AM   #1
Meek
Senior Member
Thread Starter
 
Join Date: Jan 2005
Bikes:
Posts: 518
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Does Titanium Weaken w/ Age?

Stupid question for the guys/gals in the know: does titanium weaken with use and age? I am thinking about buying an older (mid-90's) used ti road frameset, but don't know whether or not to 'trust' the bike and therefore am seeking your advice. I am a bigger rider who will be using it for a long day rides in very hilly terrain, and therefore will be putting down some good torque on the bb area etc and don't want it to fail..If it is a quality frameset from a reputable builder should this be a concern or is it 99-100% as strong as it was 15 years ago? Thanks.
Meek is offline   Reply With Quote
Old 11-14-09, 08:32 PM   #2
sannerbikes700 
Senior Member
 
sannerbikes700's Avatar
 
Join Date: Dec 2008
Location: Palo Alto CA
Bikes:
Posts: 94
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
My understanding is that Ti keeps its strength properties longer than aluminum and even steel.

But maybe some of the Ti builders can shed some light on the matter...
sannerbikes700 is offline   Reply With Quote
Old 11-15-09, 09:21 AM   #3
IbelieveLiar
Member
 
Join Date: Aug 2008
Bikes:
Posts: 25
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I will assume by 'age' you mean 'use' and all that it entails. The short answer is 'yes'.


Likely will not fail all at once. Keep an eye on things (like all bike frames). 15 years is quite a long time, but figuring out 'use' and lifespan is a total guess. Could be creampuff, or could already have cracks. Let the rest of the compenets, etc be your guide.

Ti has come a long ways in 15 years....
IbelieveLiar is offline   Reply With Quote
Old 11-15-09, 11:06 AM   #4
Scooper
Decrepit Member
 
Scooper's Avatar
 
Join Date: Aug 2005
Location: San Francisco California
Bikes: Waterford 953 RS-22
Posts: 10,259
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 194 Post(s)
Titanium alloys, like steel alloys, have a definite fatigue limit (also called endurance limit). Basically, materials with a fatigue limit can experience an infinite number of load cycle stresses below the fatigue limit without failing. For materials that have no fatigue limit (like aluminum and magnesium alloys) every stress, regardless of how miniscule, weakens the material and eventually will lead to failure.

For an excellent introduction to the pros and cons of various bicycle frame materials, read Scot Nicol's series of seven articles Metallurgy for Cyclists (links to each chapter is along the left side of the web page).

Titanium won't weaken with age unless there are repeated stress excursions beyond the fatigue limit of the alloy, which is highly unlikely in normal use. One area where early titanium frames had failures is in the welds at tubing joints. Welding titanium and titanium alloys must be performed with special precautions because these materials are highly reactive to contamination from atmospheric gases; it is important that during the welding process, the area of the weld is shielded from air by performing the welding either in a vacuum or in an enclosure containing an inert gas. Weld failures are now very rare as the frame manufacturers have learned how to prevent contamination.

A well made titanium frame should last a lifetime or longer.

My $.02...
__________________
- Stan
Scooper is offline   Reply With Quote
Old 11-15-09, 01:37 PM   #5
IbelieveLiar
Member
 
Join Date: Aug 2008
Bikes:
Posts: 25
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
They crack like all other materials, it *should* just take longer. Stays, dt's, all the usual places. A friend of mine has a very early Helfrich built atb that has been repaired 12+ times over it's life. It's been ridden incredibly hard 20+ years. Helfrich is pretty much the father of welding Ti in regards to bicycles. There is not a straight across correlation b/t material and frame.. there's a person in between who chooses tubes, welds, etc.

Anything made by Sandvik is excellent.
IbelieveLiar is offline   Reply With Quote
Old 11-16-09, 01:44 AM   #6
Falanx
THE Materials Oracle
 
Falanx's Avatar
 
Join Date: Feb 2006
Location: Finally... home :-)
Bikes: Univega Alpina 5.1 that became a 5.9, that became a road bike... DMR TrailStar custom build
Posts: 502
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by scooper View Post
titanium alloys, like steel alloys, have a definite fatigue limit...etc
+5
Falanx 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 05:23 PM.