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vibration

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67hat34c

Active Member
08xl1200c

I dropped it thursday night after running over concrete median,, dont ask. Anyhow it was slow speed as I hit brakes to avoid, front wheel hit median and bike stopped on top as it went over on left side. I did not go down just bike. Picked up bike and it went over the other way, no damage other than pipe scratches, very minor.

Damge was minor. left rear turn signal scratched and loose, Kuryakian highway bar scratched, chrome rear axle cover damaged. When i put it on jack i found front wheel bearing was bad which i suspected prior to this happening. I replaced bearing and replaced the other cosmetic stuff though not needed and now am finding a vibration. Similar to rear belt needing to be tightened but I checked it and it appears to be within spec. Checked primary chain and it was also fine. at 60 i put my hand on the lower part of forks and no vibraiton so not tire. Handle bars vibrate without holding on or loose holding, re grip and it goes away. Motor mounts look fine. Vibration with heavy acceleration and at certain speeds, some speeds constant but are smooth. (similar agan to drive belt) will ck it again i guess.

Any chance there is internal damage to forks, I am doubting it but no experience with this. Fork oil is 10w amsoil. been there 6months or so.

Also odd that bearing was bad at 18k. right bearing very loose and left seemed ok. changed both. Noticed rust coming from right bearing a couple of weeks ago so guess water instusion.
 
Check where the bars mount to the trees. The rubber mounts may have been torn or twisted in the fall. Check to make sure bars are not bent and mounts are secure.
 
bars never touched the ground.

Drive belt is fine as is the primary.

I will ck torque on motor mounts and stabalizers, handle bars etc.
Jack it up to rule out front end play then will re adjust rear axle to make sure it is alligned properly.

Vibration is caused by load. Ran to 60 pulled clutch and smoothed out.

One thing that did happen in the accident is the front tire hit the median/curb rest was simple lay down with nearly no damage.

Has to be front end issue.
 
As the Sportser custom has a spoked wheel, I would say there is probably a bit of wow or runout, especially if you hit a curb...spoked wheels do not take that type of pounding well. Tap the spokes and listen for clear metallic note approximately the same all around.

May need to use a dial indicator to check for sure, and likely your tire may have some internal damage, as a heavy hit can cause internal ply separation you would not necessarily see by visual inspection.
 
While at 60 and pulling in clutch and vibration stops adds a heighten concern.
Hopefully with added info someone will jump in that is more in tune to drive line operation. Might try typing in drive line vibration in search bar.
 
I suspect something wrong with Vibration dampening system.

Engine isolators or forks.

Something looks odd with front isolator but then again I never inspected it before. I will look at a new bike today to see if I can identify something. Otherwise i will take apart foot peg mounts and ck the torque on bolt and then possilby place jack under motor and then take off front mount and inspect.

It is not engine as the vibration is non existent at 50 or at 70. 55 to 65 is normal vibration area for this bike and also some at acceleration. It is now more pronounced than ever before. Any time in the past when it did this the drive belt was the cause. I have ruled out belt tension as it appears it has
.25" play.

Plan thus far is to put front end in air and rule out steering head, then do engine mount inspection. Lastly will rule out rear end trouble which is least likely. If nothing here then will have to pull forks and take them apart and inspect innards.
 
Go ahead and readjust your clutch cable. Perhaps as you braced for impact you pulled in the clutch and as you fought to keep her up.. the fall got the cable in a bind. Might not be disengaging all the way. Evil Knivel used to jump this things over the snake river they don't call them dirt bikes for nothing.
 
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