Ever crashed because of mechanical failure?

[akima]

Just wondering. I've seen lots of videos of crashes and read lots of accounts and it seem very rare that mechanical failure is the cause.

The poll only applies to street riding. I say that because I've read that track riding exposes bikes to far more stress than street riding and I don't want that to skew the poll when I'm really just interested in street riding related crashes. I also don't include mx riding because I have this feeling that you guys are more likely to ride a bike that... needs attention. I think my prejudice comes from the fact that I've written my mtb on many occasions when I probably shouldn't.

By "mechanical failure", I mean: something mechanical went wrong and caused you to crash. For the sake of the poll, don't answer yes if your tyres were a bit old/worn-out and you lost grip. I feel like that's more rider error than mechanical. If you're riding on really bad tyres and you crash... you were simply riding too hard for the tyres!

Examples of mechanical failure:
* wheel came off
* engine seized, locked the wheel and caused you to crash.
* chain came off... crash
* brake calliper came off / loose.
* oil/petrol sprayed out over your tyre and you slipped.
* foot-peg snapped off

You get the idea!

VOTE!!

[csmith12]

It's been my experience that fluids on the rear tire is the main cause of a "mechanical" crash. I nearly crashed a year ago at Jennings when my side fairing broke loose mid corner (turn 1 at 80+mph). It was the fairing on the inside of the corner as well. My bikes and Jennings do not get along mechanically. lol

I seen a vid on fb where a racer lost a front wheel, I will see if I can find it.

Is there supposed to be a poll here?

[akima]

You were in before the poll! Too fast!

... and... that racer that lost the front wheel...

[Rifleman]

trying to get the last 10 miles out of a ragged out, completely frog dogged chain...

I was fully adjusted out on the rear wheel adjusters and the chain was still floppin around like tissue paper in a typhoon.

chain hopped the sprocket and wadded up between the swing arm and sprocket locking up the rear...

I skidded in a pretty straight line and held it together right down to the end where I just couldn't keep it straight. Rear end kicked all the way out and i low sided at about 10 mph.

Real problem is 1 was 3 miles from home and could NOT get the chain unwound with out tools. I couldn't even get it off the road. I got a guy to run the steering while I literally horked the rear end off the ground and walked it into a near by parking lot.

note to self, last 10 miles, NOT WORTH IT!!!

[Sirref]

I've come very, very close...way too close for this reason

when I changed my chain and sprockets I forgot to put the rear axle nut back on the bike, so I went for a test ride and got back just in time for the rear wheel to come loose due to the axle vibrating out of it's proper position. Basically I almost had a rear wheel fall off

when I noticed an oil leak on my gsx-r (from the water pump) I noticed it by having the rear slide out significantly in testing, had I not stayed on the throttle I'd have been down in a painful manner. This was after the Jennings GP trip on the bike, and a different oil leak at that.

[Zombiphone]

I've had some mechanicals on the street- stuff like the shift lever coming off trying to downshift for a stop light, my voltage regulator dying mid ride causing the bike to just shut down, loose spark plug connection causing my bike to run on one cylinder, and water in my gas tank after a heavy rain that made it bog heavily until ultimately shutting down and not starting anymore- but none of those caused me to crash. Resulted in a few "coast to safety" incidents, but that's about it.

Most my crashes have been purely nut that connects the handlebars to the seat related

[alex.s]

Originally Posted by akima

* wheel came off
* oil/petrol sprayed out over your tyre and you slipped.
* foot-peg snapped off

i've lost a tire (popped and then debeaded) at 85 on the highway. didn't crash.
i've lost a foot peg, also shift lever before. didn't crash.
one time i had a very minor oil leak from a loose oil filter cover. rear tire got coated in oil. lost the rear going around a turn and crashed and slid into a curb.

[Alex]

Nope, no crash due to a mechanical. Have had a shift lever fall off my bike while riding. Have seen a fuel line pop loose on a bike in front of me, spraying fuel all over the poor guy's leg and the road below.

[NevadaWolf]

Nope.

Only two significant crashes on the street (beyond stupid can't balance the bike drops). First was inexperienced panic locking up the brakes on a corner covered in gravel resulting in a high side. Second was seriously misreading a decreasing radius downward tight corner and trying to adjust while leaned over going too quick and lowsiding.

Bike's been good.

[fast1075]

Broke a downtube on the steering neck on a '70 H2 in a corner. High side to the moon!! I had enough time to think "this is gonna suck when I hit the ground".

Proof that gravity sucks!

[cadd]

Chain caused wreck

Link to original page on YouTube.

[Sirref]

@cadd I thought you were east coast

[Whiskey]

A guy I knew back in Dublin had a chain snap at 'licence losing speed' on the motorway, it hit the rear wheel destroying it. what's left of the wheel is mounted on the wall of his garage.

[cuong-nutz]

Never wrecked due to mechanical failure.

Mechanical failure due to negligence on my part would be shifter coming loose, windscreen flying up into my helmet, clutch cable snapping, and battery connection coming loose.

[Ghostt]

Friend loaned me his spare bike to go riding with him, he had repaired an oil leak, that he failed to tell me about, only to find he didn't fix it, lowsided it at about 30mph, due to the back tire was soaked with oil, from the leak.

[Snake]

Nope I have never crashed but have come close twice.
1. Back tire lost air while going down the freeway but did not realize unti I took the off ramp and started slowing down. My rear end started fishtailing and it became difficult to steer to the side off the road. I called for help and trailered it home.
2. The clutch cable broke while in heavy traffic and had to downshift and slowdown without the clutch. Again I called for help and trailered it home.

[Motofool]

Originally Posted by akima

Just wondering. I've seen lots of videos of crashes and read lots of accounts and it seem very rare that mechanical failure is the cause............

By "mechanical failure", I mean: something mechanical went wrong and caused you to crash.......

Around 1992, I had my hardest fall due to a mechanical failure.

Early one morning, I was riding a MZ ETZ 250 to work.
In light city traffic, accelerating out of a turn and moving at around 45 mph, suddenly the rear tire made a horrible noise and the bike quickly fish-tailed three or four times until dumping me.

Before I could blink twice, my bike was sliding next to my tumbling body.
Luckily, no car run over me and I was wearing a helmet.

I had no idea about what had just happened until I lifted the bike and tried to push her to the curb.
The rear wheel was completely stuck, there was no way to make it roll.
A good soul helped me drag the bike over until a safer spot.

I finally found out that the output shaft had broken, leaving the front sprocket jammed against the crankcase.
I then removed the chain and pushed the bike back home.

The sprocket was solid on the tip of the broken shaft and the nut was kept in place by the deformable washer.
The section that sheared showed signs of corrosion, which is typical of fracture due to metal fatigue.

Fatigue is the weakening of a material caused by repeatedly applied loads.
A superficial defect from machining or heat treatment becomes a crack that keeps growing slowly, making the part weaker.

You can learn more about it here:
http://en.wikipedia.org/wiki/Fatigue_%28material%29

That was a very rare failure, because transmission shafts are carefully machined and heat treated, but there is always at least one defective part in a million.

I have no pictures of that broken shaft, but I have found and posted below a pic of a similar broken output shaft in Hayabusa forums.

[cbinker]

all my crashes are over estimating my abilities according to the conditions.

[greenaero]

No, no crashes from mechanical failure. I 've had 3 flat tires, a chain break , a piston failure and 2 brake caliper problems. The worst was my first flat tire ; I had a passenger and had a sudden inner tube failure. I had a pretty good slide before I came to a stop. The others I detected the problem early enough to prevent any problems or the moto lost its drive and rolled to a stop.

On a related note, when I was still working as a firefighter we often responded to moto accidents and I was always interested in figuring out the cause of the crash. I remember of the many crashes 2 were caused by poorly secured items the motorcyclist was hauling getting loose and getting jammed in chain drive and locking up the rear wheel. Not good

[Yamahawk]

Mid Ohio, July 2012 I had a rod bearing seize on the left cylinder of my RD350 race bike, and it locked the rear wheel at the end of the back straight... did a little rough and tumble, and the bike did too. I peed dark for a day, and had a really nasty bruise on my right heel/ankle, and a split fascia on my right gluteus maximus... that hurt for a while lol. That is the only mechanical failure that caused me to crash! Now, the low side at Nelson Ledges this past August was due to over-exuberance trying to pass Jerry and Matt coming out of turn 13... I passed Jerry, and had Matt in my sights, ...and that's all I remember!! I found myself sitting in the back of the ambulance, not knowing who the president was for about an hour... the bummer was, it didn't last

[Klondike1020]

Amendment - I need to retract my vote of - Nope - I had one incident.

Front breaks seized on a 1974 cb350, when I let off the breaks I was fine on pavement. When I went down a dirt road the front breaks did not release and I skidded the front tire and flopped down.

I didn't know what happened . Until I picked it up and tried to get it going again. I kicked the caliper for a few minutes and then road home with the rear breaks only.

I completely forgot about that until just now. It wasn't very note worthy I had just bought the bike and was working the gremlins out of it.

[akima]

Originally Posted by Yamahawk

I found myself sitting in the back of the ambulance, not knowing who the president was for about an hour... the bummer was, it didn't last

That made me laugh.

Thanks

Originally Posted by Klondike1020

I completely forgot about that until just now. It wasn't very note worthy I had just bought the bike and was working the gremlins out of it.

Well... looks like you found at least one.

[jkv45]

Nope.

Always operator error.

[spooph]

My second crash was due to an old bike's bad wheel bearings and my ignorance to diagnose them correctly. We were hitting the canyon pretty hard and the bike felt like it was sliding. I panicked and locked up both wheels. I was also very tired and learned a huge lesson in taking stock of one's physical condition while riding... Ended up on the high side of the mountain hugging a rock. Was asking the same questions over and over for 40 minutes after. Probably a minor concussion? Rode the bike home and figured it out. Got pretty lucky and learned a lot. Now, I'm a bit of a nazi when it comes to knowing a bike very well before riding it.

[Mechanikrazy]

Nope.

Closest was picking up a nail and getting a flat. Thankfully, I felt the bike acting weird and pulled over before it got ridiculous.

I am extra careful with work on the bikes. I do almost everything myself as I do have trust issues with having other people wrench on my bike.

[SLOWn60]

Every crash I've had on the street was caused by a loose nut on the seat!
Crashes on the track I blame on Red Bulls! True story!