Things to look out for......
#4
Senior Member

Joined: Mar 2000
Posts: 7,963
Likes: 1
From: Parrish, FL
Bikes: Lots
Steerer tube lenght.
Stack height, steerer tube height, stem height and a couple of spacers.
L8R
Stack height, steerer tube height, stem height and a couple of spacers.
L8R
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"Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming, "WOW, What a Ride!" - unknown
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"Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming, "WOW, What a Ride!" - unknown
"Your Bike Sucks" - Sky Yaeger
#5
Senior Member

Joined: Sep 2003
Posts: 499
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From: Willimantic, Connecticut
Bikes: '70s Puch sport tourer, '90 Peugeot Success.
You didn't say what it's made of. If it's aluminum or carbon fiber, i wouldn't buy it. CF is untrustworthy even when new; with used aluminum you don't know how many fatigue cycles its been thru, & unlike steel, aluminum has only so many before it fails.
#6
Senior Member

Joined: Aug 2002
Posts: 51
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From: Melbourne, Australia
Bikes: Trek 7200, Trek 2200, V. old Malvern Star Road bike
Steel most definitely has a fatigue life as well! However, the endurance limit of steel can be somewhat higher than aluminium, so the stress in a steel fork may be below that which will cause fatigue cracking. It is highly dependant on the grade and heat treatment of the aluminium or steel. A blanket statement that steel doesn't have a fatigue life is just not the case.
#9
Senior Member

Joined: Sep 2003
Posts: 499
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From: Willimantic, Connecticut
Bikes: '70s Puch sport tourer, '90 Peugeot Success.
Hi Cirrus. We discussed this in the thread on frame materials. From what i know, steel will never fail as long as it's never stressed beyond its rated limit, whereas aluminum will eventually fail after a certain number of cycles.
In any case, i've never heard of a steel fork failing or even developing a crack short of traumatic impact, tho i'm sure someone will give me some examples.:->
In any case, i've never heard of a steel fork failing or even developing a crack short of traumatic impact, tho i'm sure someone will give me some examples.:->
#10
Senior Member

Joined: Aug 2002
Posts: 51
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From: Melbourne, Australia
Bikes: Trek 7200, Trek 2200, V. old Malvern Star Road bike
Ebro38,
Yes, quite correct. If the stress in the steel is below the endurance limit it will "never" fail in fatigue. Exactly the same is true for aluminium. Steel "generally" has a higher endurance limit than aluminium.
I don't really know what the stress is in a bike frame, but I'm guessing that it's well below the endurance limit for steel, but may be slightly above the endurance limit for aluminium. Which is why you
may see fatigue failure in an aluminium frame compared with a steel frame.
Yes, quite correct. If the stress in the steel is below the endurance limit it will "never" fail in fatigue. Exactly the same is true for aluminium. Steel "generally" has a higher endurance limit than aluminium.
I don't really know what the stress is in a bike frame, but I'm guessing that it's well below the endurance limit for steel, but may be slightly above the endurance limit for aluminium. Which is why you
may see fatigue failure in an aluminium frame compared with a steel frame.







