Wrecked frame confusion !!!

Cabelly
Cabelly Posts: 43
edited August 2009 in Road beginners
A couple of weeks ago I cycled into the back of a van parked on the side of a road doing about 23mph. No idea why as I don't remember anything. I broke a few things including my frame. I only got enough enthusiasm to look at it properly yesterday.

:? :? :?

I knew it wasn't head on as the wheel and forks appear ok. It appears I tried to miss the van at the last minute and turned the handlebars.Both hoods have been bent almost 90 degrees and the frame has boken in two places

1. Top tube has split away from the head tube in front of the weld.
2. The downtube has crumpled upwards about 6in from the head tube and stressed where it meets the bottom bracket

I can't see any other damage but don't understand why the frame has broke

Is it possible the frame could have been defective or are handlebars bloody strong

By the way it was a Raleigh Airlite U6 Race

Comments

  • softlad
    softlad Posts: 3,513
    sounds like it was head on, but the frame took all of the damage - not the wheel or forks, which is quite feasible.

    If you are thinking of claiming a defective frame, after already admitting that you rode into a parked van, then I would suggest that you don't have much of a case.....
  • Smokin Joe
    Smokin Joe Posts: 2,706
    You don't understand why the frame broke?

    Simple, it broke bacause it was not designed to be ridden into a van. No chance of a claim succeeding, every chance of your claim form being passed around the office amid sniggers and rude gestures.
  • Cabelly
    Cabelly Posts: 43
    Nope.... not going to claim for it. But I saw recently what happens with a head on when a colleague of mine hit a car. squashed wheel and smashed forks.

    As I said- it looks like I may have turned so if the handlebrs took the brunt why aren't they or the stem crumpled ???????????????????????
  • brownbosh
    brownbosh Posts: 602
    Every crash is different fella. Plus a heavy bottom of the line fsa bar and stem is going to be stronger than a relatively light alu carbon mix frame.
  • cedargreen
    cedargreen Posts: 189
    Rode into the back of a car at night at about 20mph- bent the frame but not the forks- just the way the impact was absorbed I guess. I was on my way home from the pub. Broke my nose. Guy sitting in car got out and inspected his rear bumper. I think it was a Mk1 Escort. This was back in the eary eighties when I was a student. Well that's my excuse.

    The only way to prove that the frame shouldn't have broken is to repeat the event several times on different types of bike. It would also add a whole new dimension to the carbon vs titanium debate.

    Hope you're feeling better
  • Escargot
    Escargot Posts: 361
    Got any pics ?? The way the frame has deformed will usually tell you how it was stressed prior to failure.

    Was the front wheel buckled ?

    Do you have any pics of the damage on the van ?

    A weld can be more brittle just off the bead so could explain failure in front of the weld although I'm not sure if Alu frames are heat treated post weld. Either way the weld is usually extremely tough so will not be the first thing to fail (unless there is a fault with the weld itself).

    Your handle bars are formed into a curve and so will be pretty tough if hit head on i.e. directly on the curved section, and the fact your levers bent at 90 degress suggests they softened the impact a little. I'm surprised the bars did not slip in the stem but the bolts must have been pretty tight! Check to see if your bars have also splayed outward/inward in the same direction of the levers as they will be weaker that way.

    If you didn't hit the van head on then I'm assuming the frame would have tried to bend as the handlebars turned inward and your momentum took you forward. I'd say it was a lot to ask of a bike and the joint between the top tube/head was clearly the weakest link.

    More importantly are you ok now ? Did you break anything major ? Hope you're alright and will be back on the road soon.

    As before though if you have any photos it would help paint a clearer picture. Hope this helps.
  • Cabelly
    Cabelly Posts: 43
    Thanks ESCARGOT.
    I'll try and get some pics up tomorrow.
    I got a fractured neck and ribs, concussion and plenty bruised bits.
    Have to wait a couple of months before I get out again. :(:( but I'm itchin already
  • Cabelly
    Cabelly Posts: 43
    Heres the pics of the bike. The van had dents where my head hit and handlebars along with a tyre mark.

    DSCN3094.jpg

    DSCN3093.jpg

    DSCN3095.jpg

    DSCN3096.jpg[/img]
  • gkerr4
    gkerr4 Posts: 3,408
    how much is it costing you to repair the van?
  • graeme_s-2
    graeme_s-2 Posts: 3,382
    When I rear ended a car (he swerved in front of me and slammed the anchors on) at about 25mph, I went over the handle bars and landed on the road (he sped away from the scene so I landed on the road rather than his boot lid). The only damage to my bike was a crushed drop handle bar, and that was from the way I'd landed on the ground. Front forks, frame and front wheel were all completely undamaged!

    In my case everything rotated around the front axle and the force was absorbed by my head and right shoulder striking the road.

    Guess it just depends how you struck the van and landed.
  • brownbosh
    brownbosh Posts: 602
    Its quite interesting that it broke behind the weld dont you think?
  • carrock
    carrock Posts: 1,103
    brownbosh wrote:
    Its quite interesting that it broke behind the weld dont you think?

    Actually, the weld is stronger than a thin walled tube- not strange at all- main thing is that the other party is not badly injured- of course, any bike subjected to use for which it was not designed will fail in a number of ways, so wouldn't try to pick fault with the manufacturer
  • Rich Hcp
    Rich Hcp Posts: 1,355
    brownbosh wrote:
    Its quite interesting that it broke behind the weld dont you think?

    Not really, welds are very strong, I'd be more worried if the weld itself had fractured.

    The weld is thick and strong, the tube behind is thinner and weaker than the weld, but is designed to have a ceratin amount of flex to make the ride more comfortable

    When you stress test welded joints (usually Test peices) to distruction it is the metal around the weld that fractures, indicating weld penetration and a good weld.

    If the weld fractures that's a bad weld.

    The weld on the frame looks OK to me.

    The tube has a certain amount of flex in it and was overstressed by the impact and fractured.
    Richard

    Giving it Large
  • Cabelly
    Cabelly Posts: 43
    gkerr4 wrote:
    how much is it costing you to repair the van?

    Fortunately the guy who owns the van is a cyclist. He doesn't mind getting a second hand one which is good of him as a new one is about £400. I also know a couple of guys who work for Hendy Ford so trying to call in a favour :)
  • softlad
    softlad Posts: 3,513
    if that isn't a head-on collision, I don't know what is.....
  • Escargot
    Escargot Posts: 361
    Wow :shock:

    To me it kinda looks like a dead cert head on but am surprised the wheel didn't buckle and that the forks still look good (I guess the head tube/fork combination is pretty decent).

    To hazard a guess I'd say on impact the downtube buckled first and the top tube sheared as a result of the tension on the top of the tube. I doubt the wheels had a chance to buckle, which is interesting but I can only imagine the forks flexed enough to cushion the impact (possibly designed that way).

    Clearly I/we don't know all the info but I reckon the bike stood up to it bloody well considering you say you were going 23mph. I'm still amazed the forks and wheel look so good but then carbon is amazing stuff if used/designed properly.

    Sorry to hear you're in the wars but at least you're still in one piece and are about to ride another day :)
  • deal
    deal Posts: 857
    I managed to crash into the side of a bench at about 20mph on my mountain bike. I was following someone, looked down at bike computer for a moment, and at that very second they swerved around a bench that for some unknown reason they were cycling straight towards, ofcourse i went straight into it. Amazingly the front wheel managed to find its way in between two of the slats and then the bike came to an abrupt stop when the brake rotor made contact, i got launched into and then over the bars, bounced on the top of the back of the bench and ended up in a rock garden. The only damage was a mangled rotor and a big piece of wood missing from the bench. Very lucky since this was the first ride with a brand new wheelset and new suspension fork so could have been looking at throwing away £800 of gear after 20 minutes use!

    ps. what wheel do you have and where can i get one!
  • Cabelly
    Cabelly Posts: 43
    deal wrote:
    I managed to crash into the side of a bench at about 20mph on my mountain bike. I was following someone, looked down at bike computer for a moment, and at that very second they swerved around a bench that for some unknown reason they were cycling straight towards, ofcourse i went straight into it. Amazingly the front wheel managed to find its way in between two of the slats and then the bike came to an abrupt stop when the brake rotor made contact, i got launched into and then over the bars, bounced on the top of the back of the bench and ended up in a rock garden. The only damage was a mangled rotor and a big piece of wood missing from the bench. Very lucky since this was the first ride with a brand new wheelset and new suspension fork so could have been looking at throwing away £800 of gear after 20 minutes use!

    ps. what wheel do you have and where can i get one!


    They are Shimano RS20s. I guess you can get them anywhere.


    Thanks guys for all the replies. I guess thinking about it, it was head on and my thick head relieved the strain on the bike. Was just surprised the wheel and forks weren't mangled.

    Gotta find a frame now and get going again :D
  • Hornetto
    Hornetto Posts: 141
    The way that the frame has failed suggests a head on crash - the bending moment put on the frame at the front has caused it to fail in an expected manner IMO. The top tube looks like it has failed in tension whilst the down tube has failed in compression, which is consistent with the sort of bending moment that would have been placed on it in a head on crash (impact forcing the wheel rearwards, your weight on the handlebars forcing them forwards, leading to an anticlockwise bending moment at the front of the frame as you look at your side-on picture).

    As far as I'm aware aluminium is good in compression but not very good in tension, which would explain why your top tube is broken and your down tube bent.

    Out of interest, were you wearing a helmet? If so was it damaged and do you have any pictures? Did you hurt your head? Also do you have any pictures of where your head hit on the van? <Note: this is not intended to re-open the old helmet debate - there is already an extensive thread for that!>
    Never argue with an idiot - they drag you down to their level and then beat you with experience
  • eh
    eh Posts: 4,854
    Was just surprised the wheel and forks weren't mangled.

    Why? If wheels and forks failed in a vertical line when we rode at 23mph then you'd need new ones (and probably face) everytime you hit a pot hole at speed.

    The failure is at the Heat Effected Zone just past the weld, which is exaclty where I'd expect it, since it will be the weakest part of the frame provided the weld is of a good standard.

    Think others like Hornetto have covered most of the rest above.
  • Dr S
    Dr S Posts: 146
    In the posts above, it says just need a new frame and your off, I'd seriously consider binning the forks as well.

    Thats a major impact and short of Xraying the forks you have no idea if they have been materially weakened..

    Just my 2penneth

    Nick
    Kona Kula Supreme, the hardtail
    Scott Spark 20 the softtail
    Cannondale CAAD9 the roadie
  • Hornetto
    Hornetto Posts: 141
    I agree with Dr S. I'd be concerned about the amount of stress that has potentially been put through your forks.
    Never argue with an idiot - they drag you down to their level and then beat you with experience