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Track marshal\'s story of the AMA frame crack episode

Thought this could shed some light to all this frame snapping shit.
Found it over at cycleforums. maybe a re-post, but anyway here is the quote:

I almost thought I'd beat the rest of the list to posting this one. I'd
like those of you who are educated in mechanical failure to analyze the
pictures and see what you think. I am the Track Marshal for the MRA and
was there when this crash happened. I didn't see the impact as I was
responding to an incident on the other side of the track, however I got
there about 30 seconds after this occurred. Please consider these facts
when evaluating the pictoral evidence and the statements of the owner:

- The rider has a history of erratic riding, and considers crashing fun
and almost comical. He also has a history of bikes prepared so
mechanically poor that duct tape and zip ties are *normal*. Black flags
are typical. Some witness reports also indicate he may have been trying
to push harder and harder into that turn (going progressively wider during
the 12 laps it took him to crash), but I am still working on verifying
this.
- The turn where this rider lost it is frequently entered at 110-130mph,
coming off of a high banking to a flat section then a decreasing radius
turn. He never made it to the decreasing radius, but it'll help you form
a mental picture.
- The bike hit a concrete wall at triple digit speeds. The forks
literally separated from themselves, and the front wheel split the rim
from all 3 spokes. Ironically the brand new micron exhaust was
*untouched*, however this indicates at least to me that the majority of
the energy was dissipated from bike-to-wall impact and zero tumbling. The
bike lowsided and slid up on the left side, and stayed in that relative
position as it bounced off. We found the front wheel and bottom of the
forks a good couple hundred feet away from the rest of the bike, both
located at the top of the banking next to the wall.
- If the frame had split before hitting the wall, wouldn't the stress and
weight of the bike cause it to split beginning at the *bottom* of the
frame (forming an upside-down 'V' if the bike were upright)? This break
was top-to-bottom indicating force applied in the other direction. This
is the part where I'd like someone more educated in physics to comment.

I realize a bike wreck is a highly dynamic event, especially at 130mph.
However this thing cratered into the wall and didn't do much else, which
I'd think would help in thinking it through. Unfortunately I don't have
any pics other than what you saw (well, we do have one of the rider
standing on top of his crash like he just conquered Rome, if that tells
you anything) but would love to hear what you engineer-types make of all
this. My opinion is that the crash broke this bike, not an assembly
failure. Some 3rd party input would be welcome here.....

Thanks,

Ralph Forsythe
MRA Track Marshal, #321
 

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Re: Track marshal\'s story of the AMA frame crack episode

Ralph Forsythe is a Gixxer.com member and moderator (named 'PB')

He posted that up in the ClubRacer section the monday after he got back from the event
 

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Re: Track marshal\'s story of the AMA frame crack episode

I highsided my K5 coming out of Coppice at Donnington, thats 100mph plus. According to the marshall it was the most spectacular crash he'd seen in years with both me and the bike 20ft in the air. The crash was hard enough to snap the rim from all the spoke on the front wheel and shatter 2 of the spokes on the rear and crack the rim right thru. The wheels were carbon fibre BST's. The frame is OK. We have only given it a visual inspection as yet but it will be going on a motoliner jig to make sure!
 

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Re: Track marshal\'s story of the AMA frame crack episode

I hadn`t read hat version of events,. It was quite obvious however that if the frame had have broken whilst the rider was on it he would have been screwd, regardless of the speed he was travelling
The discription of the rider explains why he seemed happy standing on the wreck as if it was some sought of trophy.
I T-boned a car with mine ( the driver was a very lucky man that I couldn`t moove from pain from my nuts for 20 miniutes)and although it was a relatively slow impact, after examining the bike today, if the insurance co. decides it is to be rebuilt, I will have as much confidence in the frame as I had when it was new.
 

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Re: Track marshal\'s story of the AMA frame crack episode

Walk into any motorcycle wrecker/repairer and you will see the big picture. You will see any make/model with broken frames. I saw it today, as I saw it on the road 2 weeks ago weeks ago with a CBR. Give them a good enough impact and they will all snap
 

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Re: Track marshal\'s story of the AMA frame crack episode

geordiemark1

pleased to hear you are ok

cheers for those fairing panels a while ago - you got anymore bits your selling like some of your old k3 trick stuff - i.e light wheels - pm me

cheers
big fella
 

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Re: Track marshal\'s story of the AMA frame crack episode

Thanks for that.
I didn't see it in the club racer forum, didn't look hard enough I guess. I feel even more at ease with my K5 than I did before.

Cheers, miller.
 

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Re: Track marshal\'s story of the AMA frame crack episode

Sorry about the crashes guys.
They shouldn't let a clown like that on the track.
 
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