Weakest point of a MTB frame?

[Prince Albert Cycles]

1 hour ago, TheoG said:

Sorry to burst your bubble but like @DieselnDust said its still welded with the same inherent issues.  Ti does have an advantage over Al besides the higher tensile strength, like steel it also seem to have an endurance limit where Al don't.

Meaning:

1. Both steel and Ti can have an infinite fatigue life if the stresses are kept well below the fatigue/endurance limit.

2. Aluminum will fail eventually even at lower stress levels, it might just take a very long time.

3. Any kind of welding reduce the fatigue/endurance limit drastically.

Yes true but Copperhead’s titanium is a Lynskey 😇

[Eldron]

It's all about the stress raiser!

Whether it's an inclusion in base metal, a poorly designed/executed heat treatment cycle, a poorly designed joint, a overly acute angle, a badly prepared/executed weld, a poorly installed rivnut - a crack almost always starts at a weakness and propagates into a broken frame.  

This is called fatigue failure and is the most common cause of failure in metals.

Carbon fiber I know less about but would guess that compression and shock are it's main cause of failure. Also made worse by stress raisers like voids, poor layering technique, low quality fibre etc.

 

 

 

[Eldron]

13 minutes ago, Prince Albert Cycles said:

Yes true but Copperhead’s titanium is a Lynskey 😇

Titanium was far better fatigue resistance than steel and alu so it is far less likely to crack. That and it has to be welded in an oxygen free environment so it is generally welded by better welders in far more controlled environment/better QC.

[Trashy]

41 minutes ago, Chadvdw67 said:

This is welding art 😍😍😍

 

Granted, the last 2 don't have anything to do with bicycles, but they a BEYAYOOTIFULL

Maybe not as good as your examples, but this is my work.

[Chadvdw67]

12 minutes ago, Trashy said:

Maybe not as good as your examples, but this is my work.

Those are good looking welds man, I cant weld to save my life 😔 but it is something I really can appreciate, and I would love to learn how to weld properly

[NotSoBigBen]

4 hours ago, Trashy said:

Maybe not as good as your examples, but this is my work.

That is amazing, my late father in law could weld like that. Pity I never took any photos of the many welds he did on my motocross bikes in my racing days ... and for many of my mates at the time. 

He described my welding attempts as 'voeltjie ***' 🙄

[Sepia]

Great welding! Top Notch!

 

 

 

 

Edited January 6, 2022 by Sepia

[porqui]

7 hours ago, NotSoBigBen said:

That is amazing, my late father in law could weld like that. Pity I never took any photos of the many welds he did on my motocross bikes in my racing days ... and for many of my mates at the time. 

He described my welding attempts as 'voeltjie ***' 🙄

Just say it as it is "voeltjiekak" no algorithm is going to pick it up