CRASH - Component Failure
 

Had a lengthy phone call yesterday from a friend in Adelaide - he unfortunately crashed his S last week and spent 6 days recovering in hospital from a severe concussion he received in the accident. At the moment he is still very sore with some deep bruising in his ankle.

He believes the accident was caused by either the rear uni-joint seizing (most likely) or the diff bearing collapsing causing the rear wheel to lock. The road conditions were wet and it was raining steadily at the time, his S has covered around 73,600 ks. His tyres are in good condition and at least he was wearing good
quality riding equipment that took the brunt in the fall. He lost consciousness for near three hours and only remembers the ambulance.

At the moment he is very angry and feels betrayed (his words) with BMW. He feels his life was at risk with this mechanical failure and will never ride a BMW again. He has long been a stalwart of the marque.

Our question to the BBS is - Are the uni-joints a weak link in the mechanical stucture of the drive line? Are they prone to early failure and what experiences do the higher mileage bikes have? Do you think he would have any recourse with the Factory over such a dramatic consequence of this failure? Was he just plain unlucky at the time?

We are aware that the alignment of both uni-joints is critical for smooth riding and long life and are simply seeking fellow riders opinions/experience in this matter.

Cheers
TREVORSmileWavy

Wish I knew Trevor! All I have heard of is a BMW recal of 2003 R1100S manufactured 09/202-10/202 because of a potential for the rear wheel to lock. See BMWMOA Owners News Feb/03 p.76. In that case it was a question of the seating of the 3rd and 4th transmission gear wheels perhaps not securely seated on the intermediate shaft so that in shifting from 5th to 6th gear engagement of the two gears may occur simultaneously resulting in gear wheels cracking and loss of transmission capability or a lock of transmission and possible locking of the rear wheel. Sounds like your friend's S is of a much earlier vintage. Wish I knew more but there may be others out there. Sorry to hear about your friend.:(

Yes. His bike was one of the early models to hit the Aussie shores.

TREVOR

Hi Trevor,
Has the crashed S been inspected to determine which of the driveline components caused the crash? Or are both the U joint and diff damaged?

Cheers,

Frank

I haven't heard of any such failure mode.

I'd like to know more, but AFTER somebody looks at the bike and figures out what, if anything, failed. Right now, it just seems like speculation.

- Mark

Tough call, and sorry to hear about your friend. In every case I've seen any of the bearings in question fail, the races have spun in their bosses, so that no locking occurs. This is actually by design. Generally accepted engineering practices for steel races in alloy housings error on the low-interference side, such that over time, and a number of bearing changes, that a new race will eventually not fit tightly and will spin, rather engineering a tighter fit and then having a lock scenario become more likely.

So, it could have happened as is being speculated, but is highly unlikely. Also, in truly dangerous cases, BMW has a decent rep for being open about such issues, the transmission story above being a good case in point.

Last Friday I was wishing my beloved 944 didn't have such perfect weight distribution. As I was spinning, I noted that a more front weight bias can be good. I don't blame Porsche, and I'll probably keep driving them.

Hope he gets well soon at any rate.
Best wishes to him

roger

I hope this guy ultimately rebuilds his faith in BMW products, subsequent to working out exactly what happened like Mark suggests. I'm assuming he's not giving up on riding though... right?

Is it possible to find out if the rear wheel spun freely after the accident? That would answer a lot of speculation without even knowing the cause. It's pretty easy to lock a rear wheel in a pouring rain in any number of ways. If the wheel is still locked after everything has stopped slidding, then it's safe to say something's wrong.

Trevor
I'm no mechanical expert so can't help in that regard but please extend my best wishes for a full and speedy recovery to your friend.

You Aussies are crazy ;)

best wishes to your friend.

but I guess it's impossible to determine from here, what caused the failure. did a bearing break due to a product error? did the rear wheel hit a pothole which caused damage to the bearing and subsequently failure after a couple thousand miles more? was there excessive play in the rear drive which was not looked after for a too long period? was there some leak in the drivetarin that was bad-fixed by the dealer (damaging some interiors)? was the bike serviced at the dealer? if not, chances to involve BMW will be low. they will typically argument that they find the sources of failure during regular services.

good luck

Best wishes for a full recovery
My wife had a 95 GS with less than 10k that had the transmission
blew up and locked the rear wheel verysimilar to your friends account
this was an easy diagnosis because the rear wheel was locked
fortunately she unlike your friend road it to the side ofthe road without incident

I believe he was taking the bike to the local BMW dealer in Adeaide to get an official report on Monday. The Police are claiming excessive speed in the conditions etc and naturally he needs to prove mechanical failure as the cause of the crash.

Will keep you posted on the situation when I get more information.

He may be without a motorcycle for a while - made a promise to his Mother - but hopes to be riding sometime in the future.

TREVOR

I had the bearings in the bevel and paralever replaced a couple of months ago.

I'd stopped at the dealer to for a social call (I ride off road with a couple of chaps who work there). One of the mechanics was looking at the bike and noticed more play than usual in the rear wheel. He put the bike on the bench and drained the oil from the bevel box, lots of swarf came out as well. When stripped down the paralever bearing had collapsed and the bevel bearing was very close to failure. Had it failed then the wheel would have locked solid - which maybe what happened to your friend.

Happened to me, although I managed to come to come to a halt without falling off,

It is ****e, there should be a 50,000 mile inspection to look at the bits that can kill you if they fail.


http://forums.pelicanparts.com/bmw-r1100s-r1200s-tech-forum/99772-more-bits-exploding-drive-train-related.html

Have a look at this and you'll understand http://www.roadsense.com.au/speedefinition.html

"What I want to know is exactly at what speed does speed kill us"

Great question!!

Great article!!

http://www.pelicanparts.com/support/smileys/wat6.gif

B ad
M other
W ucker

[QUOTE]Originally posted by Raven
[B]"What I want to know is exactly at what speed does speed kill us"

In Australia the Police put any accident that they can't explain down to speed, which means since most accidents aren't witnessed from inside the Vehicle or on the seat , means a lot of acciddents are incorrectly recorded as speed related ! The other problem with this issue is that this info (speed) can be used to hike insurance premiums etc, there is no vested interest in the Governments or insurers getting the real reason accidents happen, why the Govt. would loose revenues and the insurance company premiums !

I thought it was rapid deceleration that kills
I saw was Barry Schene (not sure of spelling) in the 70's have a get off @ daytona @ >150 miles/hr and he slid and slid and slid tried to get up ~50 miles per hour tumbled but walked away

Its not how fast you go but how rapidly you decelerate

my personal record was not as impressive
When I was in high school I was hit by a car doing 60 mph.

During one of Florida's tropical storms and sat on the tank of the bike for 3 blocks and walked away

Pir8te