ADVrider

Go Back   ADVrider > Riding > Face plant
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 09-23-2012, 07:09 PM   #736
WayneC1
Beastly Adventurer
 
Joined: Oct 2008
Location: Sydney, Australia
Oddometer: 1,616
The fork braces are known to fail under heavy usage without axle lug failures, all bar one failure had the brace broken in the same place
The one which did not have a broken brace had the Wunderlich low guard which has an added fork brace, on it both fork legs failed

Re the YZ forks the details are in the thread here on advrider

http://www.advrider.com/forums/showthread.php?t=399113
WayneC1 is online now   Reply With Quote
Old 09-24-2012, 12:12 AM   #737
Center-stand
Gnarly Adventurer
 
Joined: Nov 2008
Oddometer: 375
Quote:
Originally Posted by WayneC1 View Post
The fork braces are known to fail under heavy usage without axle lug failures, all bar one failure had the brace broken in the same place
The one which did not have a broken brace had the Wunderlich low guard which has an added fork brace, on it both fork legs failed
I don't recall reading about the brace failures.

If it is true that all the fork tube failures (except one) have been on bikes that also have a brace failure, it is even more disturbing.

The probability of having two structural pieces failing from the same single impact and not having other significant damage seems less and less likely.

In the picture on the previous page part of the brace crack looks dirty, like it might have been cracking over a period of time. Some say pictures don't lie, but they don't always tell the truth either. It could be a mixture of light and shadow.

In the picture below the break toward the back looks clean,


Center-stand screwed with this post 09-24-2012 at 06:15 AM Reason: found another picture
Center-stand is offline   Reply With Quote
Old 09-24-2012, 09:52 AM   #738
reenmachine
Rain or Shine
 
Joined: Jul 2011
Location: Studio City, CA
Oddometer: 313
This is almost the worst thing that could happen for this thread...another bunch of pics of a failure with absolutely zero background information. Let the rampant speculation resume!

It's interesting that they're always on the right side. I bet the left side has more wall thickness because of the brake caliper mounting and the braking loads carried there.

It looks to me like the rider hit something and the fork broke at the weakest spot, which we all know and love. As others have said numerous times, it's unfortunate that the fork fails here when forced instead of degrading more gracefully, but I still think that's the nature of the old design vs. a manufacturing defect. I'm not calling it a design "flaw" either -- everything will fail somewhere when prompted to, and these forks seem to do it at the RH axle boss instead of somewhere else. BMW realized this was not optimal and reinforced the area on later forks.

That still doesn't explain the OP's failure, but neither does anything else. I doubt we'll ever know. My problem is that I enjoy my G so much I apparently don't care. I did tell my wife that if I mysteriously stack it to make sure the front fork is scrutinized, and she's got the bookmark to this thread.

If it happens to me and I live I promise you I'll get a message through somehow, black helicopters be damned! My dying wish will be to see this thread closed once and for all.

Oh, and that eBay listing makes me feel good about my resale value.
__________________
'14 KTM 1190 Adventure
'11 BMW G650GS
'02 Yamaha FZ1
reenmachine is offline   Reply With Quote
Old 09-24-2012, 11:20 AM   #739
slide
A nation in despair
 
Joined: Jul 2003
Location: NM, USA
Oddometer: 21,106
Good thing for the rest of us that we never hit the bumps these F models do so our forks never fail.
__________________
Why be born again when you can just grow up?
slide is offline   Reply With Quote
Old 09-24-2012, 12:43 PM   #740
reenmachine
Rain or Shine
 
Joined: Jul 2011
Location: Studio City, CA
Oddometer: 313
Quote:
Originally Posted by slide View Post
Good thing for the rest of us that we never hit the bumps these F models do so our forks never fail.
A troll if I ever saw one.
__________________
'14 KTM 1190 Adventure
'11 BMW G650GS
'02 Yamaha FZ1
reenmachine is offline   Reply With Quote
Old 09-24-2012, 01:00 PM   #741
slide
A nation in despair
 
Joined: Jul 2003
Location: NM, USA
Oddometer: 21,106
Whistling through the graveyard. I can easily see one who feels that frantic denying of what's obvious will save him from whatever's defective in his bike.

Nothing to worry about here. The bike's front end collapses when you're going 110 kph. The forks dig into the pavement. You get thrown over the bars. So what? All you need is to take a few giant steps, then slow to a walk. Return to the bike. Slam the wheel back on the forks and fix with mechanic's wire.

No big deal.
__________________
Why be born again when you can just grow up?
slide is offline   Reply With Quote
Old 09-24-2012, 01:47 PM   #742
reenmachine
Rain or Shine
 
Joined: Jul 2011
Location: Studio City, CA
Oddometer: 313
Quote:
Originally Posted by slide View Post
Whistling through the graveyard. I can easily see one who feels that frantic denying of what's obvious will save him from whatever's defective in his bike.

Nothing to worry about here. The bike's front end collapses when you're going 110 kph. The forks dig into the pavement. You get thrown over the bars. So what? All you need is to take a few giant steps, then slow to a walk. Return to the bike. Slam the wheel back on the forks and fix with mechanic's wire.

No big deal.
It's more your fanatical insistence that something is "obvious" when from any objective standpoint it's anything but. You employ almost every logical fallacy in the book and combine that with the hubris of blindly seeing your own viewpoint as the only one with any possible credibility, all the while bringing absolutely nothing useful to the discussion, either technical or otherwise. As if that weren't enough, you don't even own one of these bikes and your only apparent agenda here is to talk trash about BMW in a condescending, counter-productive way.

We'll never see eye to eye on this because we approach the topic (and probably almost everything else) in completely different ways. I function in an analytical world where I must examine things on technical and logical merit, seeing past emotional reactions and distinguishing actual evidence from obfuscatory circumstance. I understand causation and its love/hate relationship with correlation. I don't adopt a position because I really, really, really want things to be that way, I adopt a position because the evidence supports it and it withstands logical scrutiny.

I don't know why you've latched onto this issue so hard and why you want so badly for this to be a terrible design flaw by BMW which was then nefariously covered up by its evil legal team. Seems to me there may be better outlets for your energy, ones that might bring you more happiness, but maybe not.

Damn, I've broken one of my cardinal rules and fed the troll.
__________________
'14 KTM 1190 Adventure
'11 BMW G650GS
'02 Yamaha FZ1
reenmachine is offline   Reply With Quote
Old 09-24-2012, 04:24 PM   #743
KansasBob
Studly Adventurer
 
KansasBob's Avatar
 
Joined: Apr 2008
Location: Topeka
Oddometer: 514
Quote:
Originally Posted by reenmachine View Post
It's more your fanatical insistence that something is "obvious" when from any objective standpoint it's anything but. You employ almost every logical fallacy in the book and combine that with the hubris of blindly seeing your own viewpoint as the only one with any possible credibility, all the while bringing absolutely nothing useful to the discussion, either technical or otherwise. As if that weren't enough, you don't even own one of these bikes and your only apparent agenda here is to talk trash about BMW in a condescending, counter-productive way.

We'll never see eye to eye on this because we approach the topic (and probably almost everything else) in completely different ways. I function in an analytical world where I must examine things on technical and logical merit, seeing past emotional reactions and distinguishing actual evidence from obfuscatory circumstance. I understand causation and its love/hate relationship with correlation. I don't adopt a position because I really, really, really want things to be that way, I adopt a position because the evidence supports it and it withstands logical scrutiny.

I don't know why you've latched onto this issue so hard and why you want so badly for this to be a terrible design flaw by BMW which was then nefariously covered up by its evil legal team. Seems to me there may be better outlets for your energy, ones that might bring you more happiness, but maybe not.

Damn, I've broken one of my cardinal rules and fed the troll.
KansasBob is offline   Reply With Quote
Old 09-24-2012, 04:43 PM   #744
henrymartin
Mr. Tourguide
 
henrymartin's Avatar
 
Joined: Sep 2010
Location: South of the Great North Woods
Oddometer: 3,061
I just did a 300 mile bumpy ride this weekend, and I'm still here. I also know guys that weigh almost twice as much as me, have 4 times the mileage, and their bikes are intact after many years of offroad abuse. Here, crawl back to your holes. Pictures from ebay, of a 2001 bike nonetheless, have nothing to do with AW's thread.
That's it, I'm buying a fresh set of TKC 80's tomorrow and heading up to the wilderness for a next weekend rally.
henrymartin is offline   Reply With Quote
Old 09-24-2012, 04:48 PM   #745
Benesesso
Beastly Adventurer
 
Benesesso's Avatar
 
Joined: Jul 2008
Location: West of Phoenix, Arizona
Oddometer: 9,736
Quote:
Originally Posted by henrymartin View Post
I just did a 300 mile bumpy ride this weekend, and I'm still here. I also know guys that weigh almost twice as much as me, have 4 times the mileage, and their bikes are intact after many years of offroad abuse. Here, crawl back to your holes. Pictures from ebay, of a 2001 bike nonetheless, have nothing to do with AW's thread.
That's it, I'm buying a fresh set of TKC 80's tomorrow and heading up to the wilderness for a next weekend rally.
What year is your bike?
__________________
US out of the UN, UN out of the US.
Benesesso is offline   Reply With Quote
Old 09-24-2012, 04:57 PM   #746
Center-stand
Gnarly Adventurer
 
Joined: Nov 2008
Oddometer: 375
Quote:
Originally Posted by reenmachine View Post
It looks to me like the rider hit something and the fork broke at the weakest spot, which we all know and love. As others have said numerous times, it's unfortunate that the fork fails here when forced instead of degrading more gracefully, but I still think that's the nature of the old design vs. a manufacturing defect. I'm not calling it a design "flaw" either -- everything will fail somewhere when prompted to, and these forks seem to do it at the RH axle boss instead of somewhere else. BMW realized this was not optimal and reinforced the area on later forks.

That still doesn't explain the OP's failure, but neither does anything else. I doubt we'll ever know. My problem is that I enjoy my G so much I apparently don't care. I did tell my wife that if I mysteriously stack it to make sure the front fork is scrutinized, and she's got the bookmark to this thread.

I really don't have a dog in this fight, I just find it interesting to think about.

I do have trouble applying "logic" to the theory of forced failure, over the theory of a degrading failure over a period of time. That period of time could be 30,000 miles or 95 miles. The 95 miles might come after 29,905 miles of trouble free service and an improperly installed front wheel.

The failures that offer the most information have happened on improved roads with no mention of striking anything significant. If these were forced failures as claimed by BMW and others, logic would suggest the fork would need to be bottomed out in order to apply enough force to break an otherwise OK fork. They are considered "shock absorbers" right?

On the other hand a fork tube put in stress by a bent axle or a missing spacer, or possible other improper installed front end component, could fail over time. That time could be influenced by the amount of stress, an out of alignment wheel, loose spokes, unbalanced tire, etc.

I think most of us have held a spinning wheel by the ends of the axle and have some idea of the gyroscopic effect of the spinnng wheel. If an axle is bent or a spacer is missing the forks can be pulled / twisted in such a way as to not be aligned, as designed. When the bike is not moving it's just a slight twist or bend against the stability of the fork brace. When the wheel is rolling against the ground the gyroscopic effect wants the wheel to run straight and upright. The rider wants to run down the road on his chosen line. The fork is absorbing a lateral stress that it may not be designed to withstand. The stress could be compounded by any number of factors as mentioned above or possibly unnamed

I wouldn't wait for a failure to scrutinize my forks.

Some would suggest their fate is in the hands of the unknown. If it fails, it fails. That's fine with me.

If I'm wrong, I'm just wrong, if I'm right, a little bit of preventive maintenence might save somebody..

Center-stand screwed with this post 09-24-2012 at 05:19 PM
Center-stand is offline   Reply With Quote
Old 09-24-2012, 06:04 PM   #747
reenmachine
Rain or Shine
 
Joined: Jul 2011
Location: Studio City, CA
Oddometer: 313
Don't get me wrong, I can't help but scope out the fork bosses all the time. Every time I Rain-X the windscreen and headlight (which is pretty often) I also wipe down that area and give it a good once-over. I even pulled over recently after striking some debris on the freeway at 75 mph, mostly to inspect the tire, but I also looked at the bosses. I'm not overly worried about it, but I do my due diligence.

This problem, like so many, probably resides in the vast grey area comprising most of the real world. That is to say, it's most likely not long-term fatigue exposing a design flaw, nor is it a sudden strike leading to instant failure, a fact which, as you note, is borne out by the evidence (just riding along when...bam). My hypothesis is that it was an adequate but not awesome design that gave way in a few instances after years of hard combined on/off-road use. I contend that the critical damage occurred during a specific event some time before the failure and wasn't severe enough to cause instant breakage, but was enough to seal the fork's fate at some point down the road.

Of course that's just my opinion and it's equally as invalid as everyone else's on here.

None of that, of course, has anything to do with AW's failure, but it's just as likely that some assembly shop cockup led to that as anything else.
__________________
'14 KTM 1190 Adventure
'11 BMW G650GS
'02 Yamaha FZ1
reenmachine is offline   Reply With Quote
Old 09-24-2012, 08:13 PM   #748
henrymartin
Mr. Tourguide
 
henrymartin's Avatar
 
Joined: Sep 2010
Location: South of the Great North Woods
Oddometer: 3,061
Quote:
Originally Posted by Benesesso View Post
What year is your bike?
Mine is 09, the "newer" forks.

Seals were shot at 9k, but that's about it (fork-wise)
henrymartin is offline   Reply With Quote
Old 09-24-2012, 11:13 PM   #749
Center-stand
Gnarly Adventurer
 
Joined: Nov 2008
Oddometer: 375
I do believe that these "other" failures have something to do with AW's thread.

Her's was (for all practical purposes) a "new" bike. She is a beginning rider. The bike had the "new" design fork. It failed. We can see a bent axle. We dont see any marks or have any real reason to expect that this bike recieved a major impact in it's short road life.

If we continue to place blame for the failures on forced failure due to one or more major impacts then those who ride less spirited on only good roads might assume the caution doesn't apply to them.

"If" something improper in the assembly of the front wheel / fork is contributing to the failure then every front tire change could be a riders last.

As long as it stays active and near the top of the page this thread is serving as a PSA to those riding the affected BMWs to be mindful of the setup / condition of their bike.

A friend of mine just returned from a purchase, fly and ride on a 650 GS. He was unaware of this "potential" issue.

I don't want to be so presumptive as to speak for AW, but I doubt that she is upset about the long life of this thread, especially if she was silenced by an agreement with BMW.

+1 on reenmachine's statement from above, "Of course that's just my opinion and it's equally as invalid as everyone else's on here."
Center-stand is offline   Reply With Quote
Old 09-25-2012, 12:45 AM   #750
It'sNotTheBike
Banned
 
Joined: Jul 2011
Oddometer: 704
What boggles my mind is how the people who own these bikes can continue riding the
bikes when so much remains unknown. Are your lives really worth less than a new set of forks costs ?
Sure, you wouldn't admit to that, but every time you ride the bike with OEM forks that is exactly the bargain
you have made, whether you admit it or not.

To me, the price of a new set of forks, even Ohlins or other high dollar examples,
is trivial compared to the risk of fork failure which is incurred when riding the
bike with OEM forks. If you were in charge of an airline
company and you made such decisions relative to questionable parts and a plane
crashed and people died, no punishment would be too severe. Yet you are making
a similar choice if you ride with the OEM forks, and you are not only risking your own
lives, you are possibly endangering others on the road. And that makes you a person of
questionable morality, since you have chosen to share the risk with the rest of us
despite the fact that we do not deserve to be a victim of your poor choices.


I anticipate you deniers will want to call me a troll in order to make yourselves more
comfortable. That would be expected. But what I really am is a person
who sees a very serious risk which is impossible to quantify on one side of the scale and
the relatively small cost of eliminating the risk entirely on the other side of the scale.
This equation is absurd. If my wife had one of these bikes I would lock the bike up
so she could not ride it until I had installed new forks. Good grief, don't you people
understand that a human life exceeds the value of everything you could ever possibly own ?

Some of you must have wives, or husbands, or children, or parents, or maybe all of the
above. Why don't you ask them what they think about whether you should get a new set
of forks. I bet not a single one says no.


.

It'sNotTheBike screwed with this post 09-25-2012 at 01:11 AM
It'sNotTheBike is offline   Reply With Quote
Reply

Share

Thread Tools Search this Thread
Search this Thread:

.
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


Times are GMT -7.   It's 11:14 PM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014