Help

Marin L said:

CAN ANYBODY HELP PLEASE?

The photos show the damage to my bike after what I think was a head on collision.

I was found unconcious in the roadway and because of a head injury, I have no memory of it.

There were no lamposts or other objects to collide with and I am now trying to establish the envolvement of another vehicle.

I was cycling along a downward slope and through a right hand bend at a speed I would now estimate as 25mph.

It has been suggested that I collided with an animal. I don't agree because apart from the bike damage, my own injuries are consistent with having collided with something very solid.

I am now hoping that some person with knowledge of metals and/or bikes can tell me what degree of impact would bend the fork about 9 inches from its original position.

The bike frame is aluminium, the fork I believe is steel.

I would suggest that you post some photos of the bike.
Edit: This may get you better opinions if you are trying to satisfy your curiosity.
If you are looking to file a civil action against an unknown for recovery of damages then it would be an exercise in futility without a witness.

I thought I had added the photo's, but I was wrong. I've added them now. Thanks for letting me know.

I beleive that there would have been considerable damage to the wheel and not just the fork if you had hit something solid. I also suggest that you have someone knowledgable determine the material of the fork. It is more common to place a carbon fork on an aluminum bike rather than a steel fork. (I just checked it out, you are correct, the fork is chromalloy.)

Your injuries may have been caused by hitting the tarmac or pavement which is indeed very solid. I am a little skeptical that there was another vehicle involved. Normally people will stop and help someone who has run into them. Hit and run accidents are extremely rare but get reported widely by the media because they are so rare.

I hope you mend quickly. The best of luck to you.

You say there is no evidence (blood, paint, etc) on the tyre or wheel of any impact.

I would suggest metal fatigue at the bend where the fork comes away from the crown and bends over the tyre. Road vibration at that speed may be enough for an un-tempered fork to fail. :eek:

I think an impact with a vehicle would have damaged the wheel more. It looks like something spread out the force of impact quite a bit.

The fork crown, however, would not be able to tell whether the wheel hit a hard or soft surface if it was hard enough.

A fatigue failure of the fork probably would have bent the other way.

If fatigue contributed to the impact failure of the fork, then the fork would be cracked rather than bent, and there would be a cracked region with a remarkably smooth interface where the crack originated, along with ordinary rough cracked surfaces further along. As it is, I don't see any cracks at all.

What scenario could have occurred with a vehicle, BTW, which does not involve you either being in the wrong lane or rearending a stationary car?

My husband has a good theory - it looks like your front wheel may have dropped into a grate or crack? The damage is so bizarre - the wheel isn't bent up like it would seem like it should be if you hit something, but if the wheel were to suddenly have stopped moving from going into a grate then perhaps the fork could have bent over like that, without completely tacoing the wheel too.

He's also suggested that you may have collided with the handlebars as you fell off the bike, if the bike was angled down (if the front wheel dropped down into a hole or grate) as you fell your weight pushing on the bars could contribute to bending the fork backwards like that. Did you have broken ribs or bruises like your torso hit the bars? (with the upright position of the bike maybe even on your thighs?) - this also would have probably meant an endo for you and a great deal of impact to the front of your head/forehead.

Looks like a classic 'dropped in a grate'.

The ground was perfectly flat no dips, cracks or holes.
Road was rough tarmac.

Eden said:

My husband has a good theory - it looks like your front wheel may have dropped into a grate or crack? The damage is so bizarre - the wheel isn't bent up like it would seem like it should be if you hit something, but if the wheel were to suddenly have stopped moving from going into a grate then perhaps the fork could have bent over like that, without completely tacoing the wheel too.

He's also suggested that you may have collided with the handlebars as you fell off the bike, if the bike was angled down (if the front wheel dropped down into a hole or grate) as you fell your weight pushing on the bars could contribute to bending the fork backwards like that. Did you have broken ribs or bruises like your torso hit the bars? (with the upright position of the bike maybe even on your thighs?) - this also would have probably meant an endo for you and a great deal of impact to the front of your head/forehead.

Don't you think dropping in a grate would have resulted in the wheel hitting the far edge and getting at least a snakebite, but probably also a sharp notch smashed into the rim by the edge? The wheel hit something softer, like an animal's rib cage or maybe a car door. There's not even one broken spoke!

garage sale GT said:

Don't you think dropping in a grate would have resulted in the wheel hitting the far edge and getting at least a snakebite, but probably also a sharp notch smashed into the rim by the edge? The wheel hit something softer, like an animal's rib cage or maybe a car door. There's not even one broken spoke!

Yeah - the damages are quite bizarre - to hit something hard enough to bend the front fork with that kind of force seems like it would be impossible to not mangle the wheel too - but the wheel looks almost untouched. I can't imaging even hitting an animal could bend the fork so much, leave the wheel untouched, and especially not leave some kind of trace - blood, hair? We were thinking a slot of some sort might possibly have been able to hold the wheel nice and straight, while transferring all of the force into the fork (and eject the rider). It seems unlikely that the fork could have hit something without the wheel hitting it first - so we figured that the bend in the fork had to be from the front wheel stopping completely, suddenly and being held still so that all that momentum was put right into bending the metal.

Anyone have an photo of what it looks like to ride into a grate? I did this once a slow speed - the grate was the right way, but the pavement around it had eroded out into a nice slot - I wasn't going fast so there wasn't much damage to me or the bike, but I landed on my knuckes and forehead - summersaulted right off the bike. That was a road bike - on a more upright bike the endo might well be more gruesome - seems like you'd land on your face.

Assuming it wasn't a grate or a pallet that kind of thing, it is possible if you're really unlucky to get this sort of damage by applying the front brake sharply. Quite common, and documented, in Denmark, but generally they have mother, two kids, shopping i.e. loads of weight and on a quite different geometry bicycle.

Oops, I forgot about soft, energy-absorbing bumpers. It may be possible to smack into one of those and not bend the wheel. They have some sort of crushable honeycomb inside.

I don't find the fact that the wheel is relatively undamaged to be at all odd. A burly guy could probably bend the fork like that by hand without injuring his hands, so why can't it happen from an impact to an undamaged wheel?

yes, don't forget our friend Davis, 🙂 who smashed into the back of the car at 200kph, breaking his downtube (and top-tube, it looks like), but leaving the wheel looking ok

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garage sale GT said:

Oops, I forgot about soft, energy-absorbing bumpers. It may be possible to smack into one of those and not bend the wheel. They have some sort of crushable honeycomb inside.

I don't find the fact that the wheel is relatively undamaged to be at all odd. A burly guy could probably bend the fork like that by hand without injuring his hands, so why can't it happen from an impact to an undamaged wheel?

Good point, didn't think of that one, and from it I remember seeing a motorcycle that had had such damage. Just before a roundabout, car driver decided he wanted to off a motorcyclist. So he cuts in front, slams the brakes on, motocyclist hits back of car, bends forks etc. and rider then falls off just as the car drives away onto the roundabout and disappears.

531Aussie said:

200kph,

I sincerely hope that is a typo.

bobbyOCR said:

I sincerely hope that is a typo.

nah, (obviously) a poor attempt at humour

everyone knows he was drafting the car at 240kph

You hit something head on and hard. It is conceivable that you hit your wheel on something after you were already down and sliding, but your bike doesn't look like it. That is not any kind of fatigue failure. I did the same myself a month ago, but my fork, being composite, simply sheared off both its blades just below the crown. My wheel, as with yours, didn't look too bad from a medium distance, and the tyre was unblemished. My wheel was dead, however.
Anyway, you're never going to know for sure.

531Aussie said:

nah, (obviously) a poor attempt at humour

everyone knows he was drafting the car at 240kph

Much better.

Marin L said:

The ground was perfectly flat no dips, cracks or holes.
Road was rough tarmac.

Have you owned the bike since new? If not, any idea how much use or abuse the fork has seen? Straightening from a prior accident, repeated off-road impacts, jumping curbs, hard braking loads all contribute to fatigue damage...it's a cumulative thing.

Speaking of strange damage to forks, a guy here recently had a squirrel dart into his front spokes while going at a good cruise speed on a club ride. The squirrel went up and around, shearing a CF fork leg cleanly through in the process.