Frame failure experiences

[dorset boy]

Had two 501 frames develop a crack in the head tube ? Luckily the Carlton Kermess was under guarantee and the shop gave me a 531 Raleigh frame in exchange.

 

[Canuk]

Not broken, not really but testament to the sheer quality build of Vitus 979 aluminium frames. I tore the absolute ar#e out of mine for two winters solid in 1999. No mudguards, no cleaning, lots of salt on the roads to chew away at it.

If I'd treated a woman that way, I'd be in court . Anyhow, early one spring morning, I was about to grab the bike out the shed for another day's bash, and whoah ..! There's a 3/4 inch gap where the seat tube came right out of the bottom bracket. Literally hanging by a thread of aluminium. I probably rode around on it all day before.

On solid advice of my mate John (who knows a thing or two about bonded alu) he said 'Just cover the tube in superglue and tap it back in with a soft mallet'.

Well, nothing ventured...

And here we are twenty five years later and it's still going strong. Like my old dad used to say 'you'll have to take it outside and shoot it!'

 

[novocaine]

My understanding is that those who worked in the defence industries in those countries re-converted their skills to frame manufacture. The MTB bike boom and more positive political environment made the mix. I would almost argue the Ti knowledge was there but the bicycle knowledge and understanding of stresses involved in this period was not there at these much smaller plants.

I don't think we are arguing from opposite sides of the coin here. I suspect that within a very short timeframe the skill of the fabricator and the skill of the designer overtook in the western world that of the skill of the fabricator in the eastern world, but for a few, short years the skill of the fabricator and the knowledge gained by dropping planes out the sky without a care must have had some benefits. I'd also suggest that if you understand how to make a plan do Mach 3.X without splitting in to 20 little bits, you'd most likely understand the fundamentals of stress in anything.

now, where did I park my SR-71.

 

[bikeworkshop]

Concordeski
https://en.m.wikipedia.org/wiki/Tupolev_Tu-144

 

[novocaine]

Mmm-Concordeski
https://en.m.wikipedia.org/wiki/Tupolev_Tu-144

one should not forget the Buran.

 

[M_Chavez]

If you mean aluminium, you should write aluminium.

Is it not supposed to be "aluminum"?

 

[Canuk]

Is it not supposed to be "aluminum"?

Maybe he's American - 'Its Aloominum'!

 

[Canuk]

I did hear an apocryphal story once from a well known importer that they got batch of Russian Ti frames on the cheap because they'd been 'recycled' from a load of Mig 31's which had recently been decommissioned. This was in the early 90's and they were putting them out to the public at 300 quid, quite the bargain. I managed to see one in the metal, and it looked quite rough, but it was LIGHT! I wasn't tempted tho. Never heard anything but good reports about them afterwards. The Mig 31 was the fastest Russian interceptor jet at 3000km/h (1900mph) and was limited to 5G's at top speed.

I reckon if they know how to put a jet together that can rattle along like that, a bike frame should be a doddle....

 

[wiredfool]

I had a steel Trek 830 frame fatigue crack through the chainstay at the bridge. Probably 7-8k miles on it when it happened. Had a AL Redline/Kinesis cross frame develop a fatigue crack in the seat tube at the BB weld. No idea on the mileage there, I probably had 5k on it, but it was a former racer and I bought it used. Still miss that one.

For fatigue -- 1M cycles of a wheel is ~2000km, about 2x that for pedal strokes.

 

[bikeworkshop]

The tales in the late 90s of Russian ti being slightly radioactive?
Probably apocryphal.
The fuel pipe alloy by really being suitable for bicycle frames?
Probably true.