This is what happened to this Titaniumframed carbonforked velocipede when the veloc came to a sudden stop due to a sideways congress with a charabanc. Forks looked ok but my friend cut them up. Bike was of course paid for by the insurance company of the charabancateer.. My pal was hurt in this as indeed I was but my bike showed not a scratch. As I'd hit the charabanc with considerable veloc I scrapped my bike too. An aluminium mountainvelocipede.
Depreciation can knock the value off any pay out in cases like this. Sometimes it is preferable to seek a quote for the repairs instead, depending on the type of damage, of course.
One of mine from 1971. It is hard to see in a 40 year old photograph taken with an Instamatic, but the only true tube is the head tube. Forks pushed sideways, top tube crushed, down tube snapped, seat tube big dent and pushed sideways, rear triangle pushed sideways. Most of the equipment was ok and got reused. Me - broken collar bone and a mild concussion which gave me 4 days in hospital back in those days. I got something like £100 in total including my injuries, all sorted by CTC solicitors pretty quickly.
I'm trying to figure out the point of the OP It seems to show the CF fork intact(I know it wouldn't be safe to ride)whist the frame folded,it shows front end crashes aren't good for bikes and people. It could be highlighting bad driving but doesn't.
Perhaps I'm missing something
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"All we are not stares back at what we are"
W H Auden
reohn2 wrote:I'm trying to figure out the point of the OP It seems to show the CF fork intact(I know it wouldn't be safe to ride)whist the frame folded,it shows front end crashes aren't good for bikes and people. It could be highlighting bad driving but doesn't.
Perhaps I'm missing something
You are, you are. The weld ripped apart. I've not seen this in other frame material
Ti alloys have limited ductility to failure. Generally that value decreases in weld metal /HAZ regions.
If the tubes are heavily butted and/or the joint is angled where it joins the neighbouring tube, and it then sees a large bending load, the tube will fail away from the weld anyway, so the reduced properties in the weld region don't matter.
In the frame in question one joint has failed one way and one another. Not as bad as having both fail in a brittle mode, and not as good as having both fail by bending perhaps, but a pretty good failure mode.
Look at this way; if the top tube is (say) half the diameter of the down tube, it would only have contributed about 1/9th the total bending load to failure anyway. And if it was thinner walled too (quite likely), less than that again.
What the rider of that bike should be relieved about is that the frame failed in the way it did before the fork broke. [NB the peak load that a CF fork will sustain when in good condition isn't necessarily well related to its durability in normal service.] When a CF fork fails it pretty much snaps like a carrot; there is none of this yield and then progressive deformation that absorbs energy; whilst you can design some CF structures to do this, forks are not made this way.
If you look at a stress-strain curve, the area beneath it tells you how much energy is absorbed during the failure. A frame/fork that crumples may absorb at least twice as much energy as a part that is twice as strong that fails in brittle fashion.
I've had one or two shunts and when the parts have crumpled rather than snapped like a carrot, it has generally been somewhat more benign; you get to slow down appreciably (and fairly progressively) whilst you are still attached to the bike, which means that whatever you hit after that, you hit less hard.
Gearoidmuar wrote:You are, you are. The weld ripped apart. I've not seen this in other frame material
I've not (thankfully)seen many bikes in that state to give any kind of answer,though thinking about it I see what you mean,it's perhaps the nature of Ti welds under such violent stress. I suppose it could happen to steel Tig welded frames too but as I say bikes in front enders like that isn't something you see a lot of.
Edit:- I see Brucey's done a PM on the body
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"All we are not stares back at what we are"
W H Auden
