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Discussion Starter #1
Now that Electricals are sorted, time to figure out this front end clunk.

my bike:
K3 DL1000

I noticed the front end "clunked" when I went over surfaces that had a drop following it- since I was mostly road riding, it did this very infrequently. It is not a fairing sound- it seems to come from inside the front forks. It only happens on rebound- not compression/bottoming out. Or when the front tire comes off the ground from acceleration or dropping off a curb. The sound and feeling in the handlebars happen when the front suspension is not in the compression cycle.

Now, after spending last week riding a few hundred miles of forest service roads and UTV trails in the Black Hills, I noticed (and the guys with me could hear it when riding near me) the "clunk" happening more and more often (one shouted as he rode next to me- "is that supposed to sound like that?"). On one particularly rough decent, the front end would clunk after every rock/drop/bump - which was basically every 2-4 meters. Go over a rock (when the fork is at the end of rebound) and CLUNK! Wheelie over a rise and CLUNK when the front tire comes off the ground. Slowly navigate a rough/rocky descent and CLUNK... CLUNK... CLUNK... every time the forks fully extend.

The previous owner has paperwork showing they bought and had the dealer install Gold Valves.

A few months ago, I replaced the fork seals and put in new oil, thinking that not enough oil might affect the dampening and be the cause from a leaky seal. No luck.

So basically I think my only option is to tear the forks apart and see what I see- I am just not sure what I am looking for.

I have read many of the posts about front end "clunk" on the Wee- much of that seemed to be in the fairing and or mid stroke on compression. This seems to have everything to do with the rebound dampening - especially at the very end.

I'll post a video of the clunking sound and link to it tonight.

Does anyone have experience with dampening issues or thoughts?
 

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The first thing I would check is the nut between the handlebar clamps for proper torque.
 

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Discussion Starter #5
Sounds like some good ideas to check, I need to get a shop manual to check and make sure everything that is supposed to be in the forks are there. I put everything back together the same way it was when I installed new fork seals and oil this spring. Since I didn’t change anything, makes sense that it is the same clunk issue as before.

I purchased the Tech Spark manual... while it has ok information, the app to use it on mobile devices is severely lacking.


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Check the head bearing and make sure its not too loose. A common reason for a clunk if there is too much play.
 

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Discussion Starter #7
Also, maybe to clarify, the sound is more a “bang” than just a passive sound.

That being said, I’ll check the external bolts first before tearing apart the forks.


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1. get the front wheel off the ground to provide at least minimal clearance below tire. If you have a center stand, someone on the passenger seat should be sufficient.

2. from a kneeling position in front of the bike, grab the forks. pull them forward and push them rearward.

3. if you detect any free play, you've located the source of your thunk. it is your bearing. It needs tensioning.
 

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and...

once you've torqued them just to the point of eliminating this play, slowly rotate to the steering stop in both directions. wheel still elevated.

if any detents are felt in either direction, the bearings have developed a flat spot on their face and race interface (fun to say).

See chapter on steering bearing replacement.

EDIT: Loose bearings that make the hammering noises you have described pound flat spots into their race/face interface
 

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Discussion Starter #11
@brokeagain the riding season extended farther than I thought and I haven't had time since the last snow to dive in. Thinking I'll get in there sometime in late January / early February to see what I can find.


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I have the same issue on my 2009 Vee. The fork bearings have no slack and are properly adjusted. Fork oil changed 2 years ago with proper level, everything appeared tight when I next checked the forks. Noise only appears when riding on rough roads. At higher speeds the forks act properly with good stability, no oil leaks.

I am hesitant to open them up for the lack of understanding of " wear and tear".

Brian
 

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This seems normal for most 650 owners, myself included........
 

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If you have a Fender Extender...take it off. My '07 made a lot of clunking....yep that was it.
 

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Discussion Starter #15
@Motor7 - Interesting and worth looking into- I do have a fender extender on the rear of the front fender. I'll take a look and see but I am having a hard time imagining the banging/clunk felt through the bars coming from the fender extender. Care to elaborate? Thanks!
 

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Insufficient rebound dampening.

I believe that the forks are "topping out" i.e. coming abruptly to the end of extension without sufficient rebound dampening to soften the impact of full extension.
As only the spring preload is adjustable it may be necessary to adjust oil viscosity to cure. I believe that stock oil is 5 weight and that some have replaced it with ten weight. Once I read of a rider mixing 10 weight and 5 weight and recommending the 7.5 weight result.
Perhaps it would be worth dropping Race Tech an email to see if a parts replacement might cure it.
To see if this is the case put a zip tie around one of your fork tubes, take a ride, and then with your front wheel raised off the ground measure the fork travel you used. Full front wheel travel is 160mm/6.3in.
 

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Mine was more of "it sounds like the fairing is loose". It was not a metallic sound, and if it is some have blamed it on the cross bolt that holds the fuel tank on up by the triple tree...check for tightness.

There is also a sub frame that is bolted to the triple tree that holds on all the fairing/headlights etc. The bolts on that subframe are notorious for coming loose and making a metal "clunk". Maybe someone here has a IPL picture of that sub frame and how it attaches, since the bolts are kind of hard to find with all the tupperware in place.
 

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Here's a picture of the front sub frame to main frame connection. This one definitely had a problem. Medium strength thread locker is recommended there.

 

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My 2 bolts are tight, so wonder why I still get the clunk?
 
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