ADVrider

Go Back   ADVrider > Bikes > GSpot > Parallel Universe
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 09-16-2009, 09:02 PM   #211
trustme
Studly Adventurer
 
trustme's Avatar
 
Joined: Jun 2007
Location: Auckland , New Zealand
Oddometer: 948
Quote:
Originally Posted by cisco
I thought it was the same person.
Cisco
Different person, different bike, different country, different side of the planet, did not post in his thread as I thought it was a beat up.I did think that R75's post deserved a response, Johngil obviously thought the same.
trustme is offline   Reply With Quote
Old 09-16-2009, 11:06 PM   #212
Lion BR
I'd rather be riding
 
Lion BR's Avatar
 
Joined: Oct 2005
Location: Oregon
Oddometer: 3,679
Just to be clear John. Your opinion at one point is that the design is flawed and you are also stating that material flaw or assembly flaw could be the culprit. Considering that this has not been a pervasive problem (as far as we know), I would rule out design flaw. Material could be something erratic, as well as assembly. That is, by the amount of people reporting this problem, very few as far as I know (3 that I know), I would rule out design.

I think this bike has had design, assembly, and material problems. Two design problems are clear (water entering through the snorkel on downpours, fuel canister exit tube location, fuel sending unit, software issues). Materials have apparently been the problem with front axle failures. A few assembly points have been observed (clutch related, torque failure on a few other items). And a few things are still to be discovered (rotor side rear wheel bearing failures).

Just to keep things on the clear for everyone. Please enlighten me if I said something wrong.

Thanks,
Lion



Quote:
Originally Posted by johngil
The new frame is due in tomorrow. We will see what the VIN situation is. It could be blank, or it could have a # stamped in.
I have retrieved the bike and will be removing my Holan crash bars and any non-factory electrical modifications I have made (GPS power and satellite antennae).

I can understand the big question mark in everyone's head re: my riding habits and how this has related to my frame bending/failing.
I guess BMW could explain it better than me. They obviously believed there was some merit in my case. I did several things wrong and not by the book in this case, yet BMW still is picking up the tab. My digital camera earned it's keep. The photos have told a story and BMW bought it. To this day, the bike has not been taken apart by the dealer or BMW. I have not been obnoxious or threatened anyone. I asked for warranty repair, and I am getting it. In my opinion, it is because the design is flawed. Notice I said "in my opinion".
The masses here claim to be hammering out some pretty heavy use w/ their 800's and they are holding up fine. As Joel has said, there was probably nothing I could have done (within reason) that would produce such an outcome to my bike by riding it hard. There seems to have been some kind of material flaw, or assembly flaw involved.

I really don't know what else to add to the story here. The 800 was a "change" bike for me. Financially, I decided to hang up desert racing and enjoy the scenery w/ an adventure bike. I am a dyed in the wool KTM guy, that purchased a BMW. I really have enjoyed the bike, and plan on giving this bike another chance. I will be inspecting the ass end of this bike after every ride. I will not ride the bike w/ the stock shock, unless it is only to go to the store for a beer or three. I will report my findings.

In the same way the Bitubo fork kit eliminated bottoming in the forks, the Ohlins should prevent bottoming in the rear. Unfortunately, I waited 6000 miles before I replaced the stock shock. The damage to the frame was most likely done at this point. I really can't explain the low spring rates given to the bike. Big mistake, again in my opinion.

I feel BMW has stepped up to the plate here in regards to listening to me and doing what they feel is right.
Lion BR is offline   Reply With Quote
Old 09-16-2009, 11:25 PM   #213
johngil OP
Reseda, CA
 
johngil's Avatar
 
Joined: Jun 2007
Oddometer: 3,791
I will agree that the numbers don't indicate a design flaw. That said and absorbed, I'm going to give my bike another chance.
I will clearly state that I don't like the design. Not even a little. The overall span is too great. I also don't know what I'm talking about in regards to the engineering values associated w/ the frame/shock/bolt setup. Just using my small brain.
If nothing else comes of this thread other than folks checking their top shock bolt torque, I'll be okay w/ that.
johngil is offline   Reply With Quote
Old 09-17-2009, 12:42 AM   #214
RedHawk47
Adventurer
 
RedHawk47's Avatar
 
Joined: Oct 2006
Location: Berthoud, CO
Oddometer: 411
A Mechanical Engineer's observations

Johngil,
From the evidence presented it appears that the original failure was caused by incorrect assembly or defective parts. Assembly errors could include insufficient torque. Defective part possibilities include soft bolt, thin wall tubing, over-heating when welding, undercuts from weld, and others. My bet is on an frame defect, component or manufacturing.

When the Olin shock was installed the cause of the original failure had not been found and repaired, so it failed again. However, the Olin shock has a design feature that may have contributed to the failure happening sooner. The bolt in the OEM shock appeared to be bent at the right hand side of the shock bushing; the bolt from the Olin shock bent in the center of the bushing. The Olin two bushing sleeve method does not spread the load as well as the OEM bushing sleeve. An better sleeve for the Olin would be a full length sleeve with collars on each end.

The OEM bolt is a Class 10.9, equivalent to a Grade 8 bolt. You can buy a Class 12.9 Socket Head Cap Screw which is stronger. Yield strength is the relevant characteristic. The 12.9 is also harder, but that is not relevant here.
__________________
Dan
It's never too late to have a happy childhood. -- Tom Robbins
13 Moto Guzzi Stelvio NTX
09 BMW F800GS
99 KLR 650 A13
RedHawk47 is offline   Reply With Quote
Old 09-17-2009, 09:04 AM   #215
itsatdm
Beastly Adventurer
 
itsatdm's Avatar
 
Joined: Jun 2004
Location: Nor Ca.
Oddometer: 4,726
Intuitively the upper shock span just doesn't look like the best way to do it. Obviously proper torque on the bolt is key to providing the necessary strength for the bushings. BMW must use some type power tool to torque these bolts as I am finding it very difficult to use a torx socket and torque wrench to reach the levels required, as either the socket slips out or you end up wallowing out the head of the bolt.
At the first sign of a bending bolt, I intend to make a one piece bushing that spans the shock mount for both the shock and the seat mount.
itsatdm is online now   Reply With Quote
Old 09-17-2009, 10:14 AM   #216
Gangplank
Advenchaintourer
 
Gangplank's Avatar
 
Joined: Jul 2003
Location: Las Vegas
Oddometer: 2,294
Quote:
Originally Posted by itsatdm
Intuitively the upper shock span just doesn't look like the best way to do it. Obviously proper torque on the bolt is key to providing the necessary strength for the bushings. BMW must use some type power tool to torque these bolts as I am finding it very difficult to use a torx socket and torque wrench to reach the levels required, as either the socket slips out or you end up wallowing out the head of the bolt.
At the first sign of a bending bolt, I intend to make a one piece bushing that spans the shock mount for both the shock and the seat mount.

Because stuff always makes intuitive sense. Seen this trick before? Also why wait? A good machine shop can make you that item for less than a hundred bucks I bet. I just got new bar end spaces made for $10.

__________________
Ride more, bark less
Gangplank is offline   Reply With Quote
Old 09-17-2009, 11:27 AM   #217
BikePilot
Beastly Adventurer
 
BikePilot's Avatar
 
Joined: Jul 2005
Location: Tampa
Oddometer: 11,243
I used to race a DH MTB with a similar problem - the shock mounting bolt was quite long and had two spacers that slid into either side of the shock, just like that setup (as best I can tell from the pics, I've never seen a 800 shock setup up close in person). My fix was to ditch the spacers all together in favor of a motorcycle piston pin I happened to have laying around.

I slid the pin into the shock where the spacers would have gone, only rather than being a two-part, soft aluminum spacer, the piston pin is very hard and all one part. Its internal diameter was also much larger. With the motorcycle piston pin in place, I then sourced a very sturdy, "grade 8" bolt that fit perfectly inside the piston pin. This setup completely solved the bent-bolt problem despite some extremely hard hits (hard enough to split a 36h sun mamoth rim!).
__________________
'09 Buell XB12XT, TL1000S, H1F, M620, CR250R, KX100, XR650R, Cota 315R

Summer 2009 Ride Report http://advrider.com/forums/showthrea...1509c&t=507038
Summer 2008 RR. http://www.advrider.com/forums/showthread.php?t=367703
BikePilot is offline   Reply With Quote
Old 09-17-2009, 01:30 PM   #218
F_G
new2ds
 
Joined: Mar 2008
Location: Crown King, AZ
Oddometer: 127
Quote:
Originally Posted by wanderboy
I don't know how BMW does it, but, at H-D the dealer cuts off the frame neck and sends it back to the Warranty God and the new frame gets the same number. I have one!
That is exactly what KTM did for me a few years back. They cut off the steering head, destroy it I presume, and stamp the old number in the new frame.
__________________
Frank Staley
President in exile-Arizona Trail Riders
AMA District 31-Offroad Congressman
"Father Goose"
F_G is offline   Reply With Quote
Old 09-17-2009, 04:16 PM   #219
R75/5
Adventurer
 
Joined: Apr 2009
Location: Southern France
Oddometer: 44
Don't worry John

Quote:
Originally Posted by johngil
As for abuse??? The reason I have requested warranty service is based on my belief that I used the bike as intended/advertised. I don't see the inherit abuse you sense from across the sea. Apparently, BMW agrees. Something wrong happened in my case. I don't think BMW typically gives away a few thousand dollars worth of repairs for no reason.
When shopping for an F800 GS, try to find any BMW advertisement that shows the bike on pavement. I haven't seen any.
My wheels are still round, and my bike has never been crashed in 8500 miles. Not bad in either of our countries, I would say.
John, thanks for the reply and rest assured: You told your story and I take your word for it. If BMW NA after having had the bike in their workshop decides this is a warranty case, case closed.

Quote:
Originally Posted by johngil
I really don't know what else to add to the story here. The 800 was a "change" bike for me. Financially, I decided to hang up desert racing and enjoy the scenery w/ an adventure bike. I am a dyed in the wool KTM guy, that purchased a BMW. I really have enjoyed the bike, and plan on giving this bike another chance. I will be inspecting the ass end of this bike after every ride. I will not ride the bike w/ the stock shock, unless it is only to go to the store for a beer or three. I will report my findings.
Yeah that sounds like me. Once the testosterone levels go down you start noticing what scenery you miss by blasting by and chasing your own shadow. And inspecting the bike after a rough day doesn't sound like a bad idea either. As I pointed out, I am not a big offroad expert at all and most of my wisdom is second hand. The few occasions I actually did get off the beaten path was when I desired to go from point A to point B and discovered at point D, which is inevitably long past point C (= the point of no return) , that the bloody track is now a river, a landslide, a rumor, something suitable for a donkey, or garmins idea of a cruel joke...
Though, sometimes I get around to play in sand, too and in that context I had the priviledge to ride one or the other trail in the Magreb together with some people who have contrary to me substancial off-road experience, which they aquired through various rides across Africa. Riding beyond the event horizon of the dealership so to say … One thing that I picked up around the campfire is that once you're really off the beaten path and you start bottoming through the shock(s) your „internal“ radar should go to code orange immediately. Meaning: go off the throttle and take it easy for a while to see if at a lower speed this happens again. If it does, a quick stop and run-through over shock, shock-bolts and swingarm are a good idea and might reveal that your shock-spring is history or the shock is already spouting oil. In that case the next big whack has a fair chance to end up in a rough landing. But even if this remains a single occurence you still earmark this inspection drill for the next convienient opportunity, latest at the end of the day. And the further the bike is beyond the 200kg line the more religiously you'd like to go through with that. But now enough of my hindsight-comments here to a water-under-the-bridge case.
Good luck with the bike John!


@JoelWisman
Thanks for adding some grey tones to a thread which had a lot of black and white. I agree with you that that making everything stiff like a board down there – like suggested by some people here – does intuitively not sound like a too good idea: Once you bottom through, the energy goes somewhere and not all can go into elastic deformation of the frame. So casting the shock bolt in concrete just means the stress on the steering head and the swingarm gets bigger. And I guess I'd rather have my shock bolt bending than long term a frame fracture close to the steering head. Having said that, I really dunno whether that particular construction back down there is reliable or long term up to the task. I guess I make up my mind in two years when more people clocked up 30-40000km with a fair stretch of offroad in the mix and things did hold up well. Right now I am too busy hunting down five SKF 6204 Explorer if you catch my drift ...


@trustme
Quote:
Originally Posted by trustme
If R75 is right, then BMW should make it transparently clear that these bikes are not suitable for offpiste.
Dunno if this was the bottom line of my message.
Upon reflection I would rather formulate it along the following lines:
Marketing folk should be put up against the wall when the next revolution comes around.
Folk that believes in marketing will be put up against the wall when the next revolution comes around, because they're fools and the marketing folk is among the revolutionaries.
R75/5 is offline   Reply With Quote
Old 09-17-2009, 05:05 PM   #220
itsatdm
Beastly Adventurer
 
itsatdm's Avatar
 
Joined: Jun 2004
Location: Nor Ca.
Oddometer: 4,726
[quote=Gangplank]Because stuff always makes intuitive sense. Seen this trick before? Also why wait? A good machine shop can make you that item for less than a hundred bucks I bet. I just got new bar end spaces made for $10.
/quote]

You think that tooth pick will be strong enough.
itsatdm is online now   Reply With Quote
Old 09-20-2009, 09:44 PM   #221
RedHawk47
Adventurer
 
RedHawk47's Avatar
 
Joined: Oct 2006
Location: Berthoud, CO
Oddometer: 411
Quote:
Originally Posted by JoelWisman
It also seems to me that if the bolt is the correct strength and torque, it would be carrying mostly tension and perhaps shear while the bushings and spacers carried the bending forces.

This is why I think the bushing in the Ohlins shock could be critical.

I realise Johns mount bent with both the oe and Ohlins shock, but find no reason it could not have bent for two unrelated reasons.

My guess is the first bend was from an incorrectly torqued fastener. Further bends were due to the bushing in the Ohlins shock having less flange area / being split, the frame flanges being bent slightly out of alignment, or a combination.
After some discussion with Joel I have decided that his theory for the failure is most likely. Here are some discussions of the factors.

The shock mounting bolts, upper and lower are to be torqued to 100 NM (74 ft lbs-force). This makes a solid stack of the shock bushing and spacer bushing between the frame flanges. The dealer shop manual also specifies thread locker on the bolt although the repair manual CD I have does not mention it.

Failure #1: If the bolt is loose the shock forces are resisted by the strength on the bolt, in shear and in bending. If the bolt is properly tightened the shear load gets some help from the friction of the bushings against the mounting flanges. But more important the bending forces are resisted by the bolt and the bushings; if the bushing is twice the diameter of the bolt the combination would be four times as stong/stiff.

Failure #2: Once the mounting flanges are bent the bolt can no longer make a solid stack so the situation is the same as a loose bolt. The Olin bushings exacerbate the problem because they are short and provide less support against bending.

Failure #3, Frame cross tube bending: Once the bolt has bent the shock forces are being absorbed by the mountng flange in the center of the bike (transferred from the shock thru shear of the bolt).
Very little force is going to the outside flange. The resulting load is apparently more than the cross tube can withstand. Manufacturing defects could have reduced the strength of the cross tube; possibilities include wrong gage tubing and welding defects.

Bottom line summary: Check that your shock mount bolt is properly tightened. If you remove it put some thread locker on it and properly tighted it.
__________________
Dan
It's never too late to have a happy childhood. -- Tom Robbins
13 Moto Guzzi Stelvio NTX
09 BMW F800GS
99 KLR 650 A13
RedHawk47 is offline   Reply With Quote
Old 09-20-2009, 10:24 PM   #222
johngil OP
Reseda, CA
 
johngil's Avatar
 
Joined: Jun 2007
Oddometer: 3,791
Quote:
Originally Posted by RedHawk47
Bottom line summary: Check that your shock mount bolt is properly tightened. If you remove it put some thread locker on it and properly tighten it.
That is the nuts and bolts of this entire thread, I believe.
I will be getting my bike back soon, and you bet I will be checking the torque of the shock bolts frequently.
johngil is offline   Reply With Quote
Old 09-26-2009, 08:37 AM   #223
johngil OP
Reseda, CA
 
johngil's Avatar
 
Joined: Jun 2007
Oddometer: 3,791
Day 39 in the shop. Dealer says they needed to purchase e few special tools.
johngil is offline   Reply With Quote
Old 10-02-2009, 11:30 AM   #224
DockingPilot
Hooked Up and Hard Over
 
DockingPilot's Avatar
 
Joined: Mar 2004
Location: Andover, N.J.
Oddometer: 9,365
John,
I just returned from a 2,400 mile trip. About 1,800 of them off road. Bike loaded with gear, pre load adjusted for it. The bike took a pounding, in fact I tacoed a rim. Deep water, and hard hits for sure over 12 days. I just stripped her to clean and change oil and filters. I also inspected my shock bolt while I was at it. Its straight. I gotta think if it was going to go south it most definitly would have on this trip.
Any news on your front ?
__________________
Frank Reinbold

"Every bike I ever had, was the best bike I ever had, when I had it"
DockingPilot is offline   Reply With Quote
Old 10-02-2009, 06:33 PM   #225
johngil OP
Reseda, CA
 
johngil's Avatar
 
Joined: Jun 2007
Oddometer: 3,791
Bike is coming home tomorrow.
With all the positive testimonials from other 800 riders here, I'm going to give the bike another try.
johngil 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 09:59 AM.


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