Broken titanium fork end

[Nelson Longflap]

My son's 9 year old 2 speed Brompton with all the titanium bits was discovered to have a cracked fork end. The fork end seems to be created by using a press to squash and shape the fork blades rather than welding in a casting.

The odd thing is that when compared with a 2017 Brompton titanium fork end, the 2017 version is about twice as thick. Which makes me wonder if the reason for the increased thickness is a history of failures in the thinner titanium fork ends. What is the collective knowledge on the matter? Has anybody seem anything similar?

TIA

[1nterceptor]

Yikes, that sucks. I also have a ti/superlight. Can you give me some insight on hos this bike was used?
Rider weight, curb jumper?, cobblestone roads, etc. I'm trying to see if I can avoid the same fate. Any
possibility the factory will warranty?

My 6 speed titanium is from 2013; seems ok so far. Over 200 pounds, don't jump berms/curbs, ride in
pothole riddled streets. But I tend to avoid big holes.
https://www.youtube.com/watch?v=pNuuT-nRer4&index=37&list=UUHyRS8bRu6zPoymgKaIoDLA

[LittleWheelsandBig]

https://brompton.zendesk.com/hc/en-us/articles/115000554605
Apparently 5 years for frame parts.

I've not heard of a Brompton Ti fork failing in this manner before now.

[Nelson Longflap]

Thought I should draw this thread to a conclusion (with apologies for the delay - I've been busy on holiday) ... Brompton's customer service was excellent and provided a replacement titanium fork foc, despite the bike being out of warranty    The new fork ends are indeed thicker than the original ones.

One thing I learned talking to somebody who knows about metallurgy is that titanium, while inherently a strong material, is more brittle than steel. I wonder if this explains why some titanium parts crack due to minor flaws that steel would be able to tolerate?

[Torslanda]

Cynical old me thinks the reason most Ti manufacturers offer a 'lifetime' warranty on a frame is because they know it's going to break.  Working on the assumption that around 5 - 10% of customers will keep the frame for ever, they keep their warranty returns at an acceptable level.

[onerousdeporte]

Did you get to keep the old fork?

[Nelson Longflap]

Did you get to keep the old fork?

No.

[quixoticgeek]

Not seen a crack at that end, but a friend here in .nl with a titanium fork had a big crack down the middle of the stearer tube.

J

[Gattopardo]

Cynical old me thinks the reason most Ti manufacturers offer a 'lifetime' warranty on a frame is because they know it's going to break.  Working on the assumption that around 5 - 10% of customers will keep the frame for ever, they keep their warranty returns at an acceptable level.

Very hard to weld successfully.

[rogerzilla]

Not seen a crack at that end, but a friend here in .nl with a titanium fork had a big crack down the middle of the stearer tube.

J

That's far nastier.