BMW Enduro skidplate cracked my engine case

Discussion in 'GS Boxers' started by Jaws, Oct 2, 2012.

  1. Jaws

    Jaws Awesome Adventurer

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    No, that is not correct. The BMW alternate skidplate mounts to the rear of the engine. There is huge difference between the two plates you really need to see them in person.

    In summary:
    BDCW mounts to the frame in the rear and is much thicker gauge aluminum and has a rubber pad
    BMW Enduro (or HD or Alternative) mounts to the engine case in the rear, which where mine cracked
    #21
  2. Wallowa

    Wallowa Diver Down

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    Thanks...the frame mount is needed indeed...I will check them out...I have a thick and well made after market skid plate that gives excellent protection to a point..the point is the kind of impact that broke your engine case.

    I can assume the frame mount will protect the rear engine case...but I am still concerned about the front mount which if I understand it correctly, still mounts to engine case...ANY engine case mount points can transmit enough force to the case to break it; with or without rubber blocks or collapsible sections if the case is the attachment point it can be broken...a bent or cracked frame out in BFE is most probably a 'work around' issue, but a broken engine case...most places I ride do not have welders or transportation out....

    Of course there is always JBWeld :D
    #22
  3. JimVonBaden

    JimVonBaden "Cool" Aid! Supporter

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    I must have missed it then. How about some photos of the mounting system? Also, a comparrison between the BMW one and the one you have.

    Jim :brow
    #23
  4. MJS

    MJS Long timer

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    Expecting a big, heavy endro bike that uses the engine case as a stressed member of the frame to be impervious to engine damage may be asking to much.

    I personally know of two 1200GS bikes where the engine case cracked at the front upper frame mount. Since there is a pressurized oil galley at this location, those cracks were immediately obvious. This in a location that requires the motor to be dropped in order to access. It is not easily welded due to the needed oil passages and the inability to clean the internal passages.

    Knowing the limitations of your machine and riding within those limitation so as not to damage the equipment ranks high on the list of riding skills. Or so I was once told by by some guy named Jimmy Lewis :huh
    #24
  5. Jaws

    Jaws Awesome Adventurer

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    Hello Wallowa and JimVonBaden,

    I'm going to try to answer both of your questions and may try to add pictures later if this doesn't help.

    Front Attachment: Unfortunately, I think we are stuck mounting all of the plates to the front of the engine case. All of the new plates use a solid through bolt that is fairly stout. It is a horizontal bolt so it is better than using the corner bosses, but it still mounted to the engine. It acts like a pivot so the rubber pads supplied by both plate mfg's probably reduce/absorb some of impact/jarring that would be transferred to the case through this bolt. However, because this bolt acts like a pivot and is at the very front of the plate, most of the impact force will get transferred to the rear of plate.

    Rear Attachment: With the exception of the BDCW plate, most of the other plates (that I'm aware of) attach to the rear engine mounting bosses which are inline with the bottom of the engine and the direction of impact. This same mounting boss is what is outlined earlier in this thread as the piece that was welded on my bike.

    Some companies use plastic/rubber mounts to try to minimize damage to the engine case in hopes of the mount failing before cracking the engine case. The BMW Heavy Duty/Enduro/Alternative plate is the absolute worst offender since they use a rigid steel H-bracket to mount to the engine case. Now, instead of ripping off the plate, the solid H-bracket keeps the plate attached to the bike and will crack the engine case instead.

    In contrast, the BDCW plate does not use these rear engine bosses at all. It mounts to the frame which will be able to absorb the impact forces much better than the cast aluminum engine.

    Here is a picture of the BDCW plate. The high rear mount goes all the way up to the frame:

    [​IMG]

    Mick from GS Riders of GO AZ BMW took a video of my bike on the trail that does a very good job of outlining the differences in the plates. If you look closely, you can see the differences in the rear mounts. Unfortunately, I don't know how to link directly to their video. Just look for the video with my bike leaking oil all over the place if you go to their page.

    Edit: I fixed the link above
    #25
  6. Jaws

    Jaws Awesome Adventurer

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    You do realize your profile picture is much more radical than anything that was done in the Lockhart Basin that day right? :freaky

    I definitely agree with your statement, but still think it's important to point out that the BMW Enduro plate is unique in that it actually adds leverage to the impact forces and rigidly mounts to the rear of the engine. All of the other plates on the market either use rubber mounts or mount to the frame.

    Either way, I'll be sticking to my BDCW plate for those "incidental" hits, I'm sold! :clap
    #26
  7. Wallowa

    Wallowa Diver Down

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    Good ideas and views, except that even JL drops bikes or pivots a rock up under a bike....you can be the most skilled rider in the world and make all the correct judgment calls and still bash the plate..the upper frame damage I would guess is less likely than the lower case.

    Sooo. It is logical to consider a case protection plate that is not attached to the engine case...but hey, I could be wrong!:wink:
    #27
  8. MJS

    MJS Long timer

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    I'm not saying I don't abuse my bike...:roflUp untill a couple weeks ago it still had the stock skid plate. Though it has been ripped off and beaten back into place once or twice.

    I agree and I've got the TT plate on my HP2.

    I'm just saying that even the best plate out there is not going to guarantee you can't damage the bike. And riding with a consideration to not damage the bike is important. I'm certainly not accusing Jaws of being careless. Well except for maybe riding with Jason and Mick :lol3:lol3:lol3 (just kidding, I've ridden with both)

    Cheers
    #28
  9. bemiiten

    bemiiten League of Adventures

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    [​IMG]
    The BMW plate in fact mounts to the frame at it's rear most point. The center horizontal mount should have yielded before causing damage to the case, surprised it didn't. Also looks like the front mount on the BMW plate might be more forgiving then the BD by also using a horizontal attachment that should provide some yield. ​
    #29
  10. Jaws

    Jaws Awesome Adventurer

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    Here are some screen shots from the GS Riders of GO AZ BMW video. They show the offending bracket on the BMW plate that I don't personally like. The red arrow points to bracket and the circle is where the case is cracked.

    [​IMG]

    You can see it's not going to break or bend, which means something else is going to give. In this system the cast aluminum engine case is the weakest link. The bracket also acts like a lever arm, so a light hit on the very back of the plate could easily break the engine case at the mount.

    [​IMG]
    #30
  11. drewcrew

    drewcrew Adventurer

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    Well before that day Jaws was a virgin to Jason, Ryan, N Mick. I gotta have my fun too. :D
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  12. Jaws

    Jaws Awesome Adventurer

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    Hello bemitten,

    Here are some points from my ownership (and use) of both plates:

    The rear most mount of the BMW plate is pretty flimsy and you can move it by hand. The middle bracket is the one that is going to take the brunt of an impact.

    As shown in the pictures in my previous post, the center horizontal mount (H-bracket) is the most stout part of the system and actually caused the damage. It's steel and a thicker gauge than the plate or the cast aluminum engine it's mounted to. It's not going to yield.

    For the front mount, both plates use the same identical horizontal mounting bolt that pivots so there is no difference or advantage. The BDCW plate covers more of the front of the engine and exhaust so it actually provides more protection from rock dings, etc (IMHO).

    I definitely understand the speculation about the plates. I bought two of the BMW plates myself because I had never seen a BDCW in person. Having had my experience I would never go back. I would stick with the stock GS plate with the rubber mounts before using the enduro plate. The stock plates at least rips off w/o causing more damage. I will never mount anything like the steel H-bracket to another GS engine again.

    I suppose it really depends on how you use your bike. If you don't use the skid plate and never roll it over large logs, or take it down trails with large rock outcroppings, then any plate will probably suffice. This is my second GS and I bought it just to do all of those things, so I prefer more protection at this time.

    If you like the BMW plate, I would recommend you remove the H-brack entirely so it doesn't have the opportunity to crack your case in a truly incidental hit.
    #32
  13. bemiiten

    bemiiten League of Adventures

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    Perhaps if the H bracket was flat and mounted to the original sacrificial mounts, would be a safer bet. That or a trip across it with a cut off wheel to create some weak spots.
    #33
  14. Jaws

    Jaws Awesome Adventurer

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    :D.....just so ya know (wait for it).....while riding the Lockhart Basin (with the bike fully loaded from Michigan), I didn't damage one turn signal, break a windshield (uh-hmm DrewCrew..), bend my handle bars, scratch my paint, break a kickstand (uh-hmm DrewCrew again..), or do any other cosmetic damage to the bike the entire day.....although afterwards Ryan did tell me not to ride it like a 250cc, and mentioned something about the bike being equipped with two brakes? Who knew....:ricky

    Of course both the bike and me made it that far with help from Jason, Ryan, Mick and DrewCrew...:super
    (I would do it all again, it was a freaken blast!)

    -Cheers back at ya-:beer
    #34
  15. L21

    L21 Been here awhile Supporter

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    I have the BDCW plate on my 950adv and my 1200gsa and its a nice peace of mind. Kurt has worked hard to make a skidplate that works. For me its BDCW all the way :freaky
    #35
  16. Jaws

    Jaws Awesome Adventurer

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    I agree with both those points. You could probably get some p-clamps and bar stock from the hardware store and go right up to the frame.....or, the Black Dog does come in a nice powder coated black color (okay, that was the last plug).

    My advice is just don't mount anything rigid to the engine.

    Enjoy! :beer
    #36