DL650 front suspension oddity

Discussion in 'Land of the Rising Sun: ADV Bikes from Japan' started by tweeder, Mar 4, 2012.

  1. tweeder

    tweeder Farkle Queen

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    I changed the fork fluid on the Wee this weekend. All went fine, took pictures, put it back together the way it came apart, etc.

    When I went to reinstall the forks, the "clutch" side fork was longer than the "throttle" side fork :huh. We realized this when we went to put on the front wheel and the axle holes wouldn't line up. My wife smartly recommended loosening the triple clamp bolts, sliding the fork up temporarily, installing the axle, then compressing the fork and tightening the clamps again. Each fork is now flush with the top of the top triple clamp. We tightened the fork clamps, and lowered the bike onto both wheels to let everything settle (bolts were snug but not torqued down).

    I had to remove the wheel and forks again (trying to adjust the steering head bearing...) and the same problem happened again. Fearing something was amiss, we removed each spring and measured them (stock) and they were the same height, as were the spacers in each fork. Once again, during reassembly, the fork had to be raised in the clamp, axle put through, then lowered in the clamp.

    I don't think my forks are bent. I have only dropped the bike once at a stand still at a stop sign, and it has ridden fine since I've had it. The only problem I've had is if I take my hands off the bars between 35-50 MPH while de-accelerating, the bars shake a whole bunch (hence the steering head bearing adjustment). The tires were properly inflated (rear Tourance, front Trail Attack).

    Any recommendations? I've done my best with the steering head bearing adjustment, and just want to put it together and try it out...
    #1
  2. MCRIDER007

    MCRIDER007 Adventurer

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    Since this started with a fork oil change, did you check to make sure your oil height is the same in each fork?
    #2
  3. tweeder

    tweeder Farkle Queen

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    Yes, and thank you for the reminder. We measured 150mm from the top for each tube, after letting the forks sit for a bit and cycling many times to get rid of any air bubbles.
    #3
  4. MCRIDER007

    MCRIDER007 Adventurer

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    I am assuming that your 150mm oil height was with the forks totally compressed and the springs out......did you try putting the springs in the fork tubes (after the oil was added) when the tubes were fully compressed and verifying the top of the springs were the same height (this is determine if the springs are sitting on the damper rods evenly). You will need to push down on the spring on the short fork tube to see if the spring is slipping over the top of the damper rod it is sitting on.
    #4
  5. precarious

    precarious Been here awhile

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    Stroms like to shake; it's what they do. Mount Michelins and balance with Dyna Beads and be happy.

    The forks sound strange, though... Being bent wouldn't affect length like that. Curious...
    #5
  6. precarious

    precarious Been here awhile

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    Some bikes have unequal forks due to the axle design. Some have an unrestricted extension on one fork; one fork will deal with rebound, the other with compression. When tied together, they work as one.

    Not sure about the DL650.
    #6
  7. tweeder

    tweeder Farkle Queen

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    Yes, the 150 mm measure was with the forks totally compressed and the springs out.

    However, when we went to reassemble with the springs, one fork tube was harder to assemble (I believe that it was the clutch side). Could this have been caused by the spring not sitting on the damper rod evenly, even if we never did anything with the damper rods? Like I mentioned, all I did was remove the spring, washer, preload, and spacer.

    To check this, can I remove the spring with the fork in place (remove the handlebars, etc) or do I need to remove the whole damn fork again?

    Thanks again!
    #7
  8. Flashmo

    Flashmo Whatever...

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    Something is amiss on your re-assembly, not sitting right in the tubes. The forks on the DL should be the same length. Just did mine again a couple weeks ago.
    #8
  9. MCRIDER007

    MCRIDER007 Adventurer

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    I think the problem is with your short fork and the reason you have a "short" fork is because there is some kind of overlap between the spring and the damper rod or between the spring and the spacer. The spring should sit on the damper rod, if you are able to push the spring down the damper rod then you have found the problem and you probably can do that test with the fork in place. The microfiche shows a piston ring sitting on top of the damper rod that separates the spring from the damper rod....I'm not sure what a piston ring actually is but if it isn't there anymore then the spring could be slipping. One other possibility is that the spring has a narrower diameter at one end and that end needs to be on the damper rod or that the seat on the damper rod is broken allowing the spring to overlap.
    #9
  10. tweeder

    tweeder Farkle Queen

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    Consensus seems to be operator error. You are probably right.

    As I recall now, when we had the forks empty and the springs removed, one fork was actually shorter when standing up on the ground than the other (clutch side was shorter than the throttle side). It sounds like I need to disassemble and check again. If I have not removed the damper rod or loosened the nut at the bottom of the fork, what could cause this discrepancy in fork length?

    Do I just need to try to compress the fork more to see if the lengths match? I recall not being able to compress the fork any more than it was.

    If the clutch side fork was indeed not compressed all the way by about 10-15 mm, would this then make my measurements for matching fluid level in each fork invalid?
    #10
  11. MCRIDER007

    MCRIDER007 Adventurer

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    I don't think so....at least if it were me, I would want to be able to look at the damper rod and verify there isn't anything wrong with it and the spring was properly sitting on it. The oil you take out may already be discolored but if you empty it into a clean container than you should be OK to reuse it.
    #11
  12. MCRIDER007

    MCRIDER007 Adventurer

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    If you did not fully compress one fork when you were adding oil and measuring oil height then you probably have too much oil in one fork...which would result in different air space giving the forks different compression rates...but the length of the forks after assembly would still be the same.
    #12
  13. El Gato

    El Gato Been here awhile

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    This sounds funny to me. Are you the only owner? Is it possible the previous owner had the forks apart, and perhaps forgot to put the oil lock back into one fork. Is there perhaps an Emulator or Intiminator in there that's cocked in one fork, not allowing the spring to sit flush on the damper rod? If you're not the only owner, and the forks are unequal height with no springs in them, I'd disassemble them completely to see what's up.
    #13
  14. tweeder

    tweeder Farkle Queen

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    I am the second owner. I don't believe that there are any aftermarket parts inside, but I'm not sure.

    The spacers were the same length, but they were PVC, which leads me to believe that someone did something with the forks at some point.

    As for the oil lock, pardon my ignorance, but what is its function? If it locks the oil in somehow, would I not notice a leak, or does it lock the oil in a certain place within the fork?

    If the forks are unequal length w/no springs in them, that's past my comfort level (in case you can't already tell), even if I have a service manual :(:
    #14
  15. PeterW

    PeterW Long timer

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    Oil lock piece shuts the compression damping circuit off when the fork is nearly fully compressed and raises the resistance to further compression massively. Basically it's there to try to turn massive hits into something the components will survive.


    Easy enough to get the fork caps off, just loosen off the top bolts, you can then pull out the spacers and springs to make sure everything there is the same length.

    If you take the fork caps off, the forks should extend to the same amount - if they don't something is wrong - probably due to something coming loose and jamming, no clue what though.

    The plastic spacer suggests aftermarket springs, a common mod, but other than that, no idea what's gone wrong.

    Pete
    #15
  16. tweeder

    tweeder Farkle Queen

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    Thanks for the tips. As I said, the springs and the spacers are the same length, so I don't think that that is the source of my problem.

    Any markings on the springs to check for whether or not they are aftermarket? They are a progressive rate, but as I understand the stockers are progressive (at least according to my manual).

    As I recall, several months back I tried loosening the fork bolts to with the wheel up to try to let the forks "untwist" as a quick way to check if the decel wobble was due to that. When we loosened the forks, the clutch side one popped up until the preload adjuster hit the handlebars. :norton
    #16
  17. PeterW

    PeterW Long timer

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    Damper rod has come unscrewed one side ?. The PVC spacer screams aftermarket springs . The stock spacer is metal. That alone won't cause this unless the springs are different lengths laid side by side - or obviously different.

    The other possibility is that the bike took a hit at some point and someone put an SV fork leg in there - but that's so gross as to be almost unbelievable.

    Pete
    #17
  18. Reposado1800

    Reposado1800 Juicy J fan!

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    The offending fork is going to need to be disassembled. I bet there is a cartridge emulator in there that fell over sideways and is jamming up the spring at the bottom.
    #18
  19. Flashmo

    Flashmo Whatever...

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    I would pull and drain both forks and start looking for the discrepancy between the two. Re-use the oil, on re-assembly, but you'll need another few ounces.
    #19
  20. MCRIDER007

    MCRIDER007 Adventurer

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    Interesting comments.....I hadn't realized that you are the second owner.....which means either fork could be the problem. If the problem is in the "long" fork, I wonder if that side could have an emulator whereas the "short" fork does not. I don't know if you really have to completely disassemble the forks to find the problem but you may have to disassemble one of them to fix it.
    #20