Not sure when it started but my bike has developed a clunk when I let off the throttle and again when get back on the throttle - every time. Closest I can explain it is if a truck has a bad u-joint and you get on/off throttle and it has to take up the slack.
I haven't started digging in yet but the chain and sprockets are only a couple thousand miles old but everything else has about 18k miles.

Any thoughts from the collective geniuses?

 

I would be starting with the chain, if it is a bit loose you can get that feeling. Then onto sprockets cush drive etc, although should not be an issues on that mileage.
What bike is it?

 

I was thinking cush drive just because that is the only original piece but since I haven't been able to actually look at it there is no telling.

It's a 2002 F4i.

 

Your description certainly sounds like drive train related and chain and sprockets fit the bill to a T. A close examination of that would be first on my list of things to check.

 

I'll get it up on a stand when I get back from vacation (not riding it on vacation) and inspect the drive line from front to back.

Thanks!!

 

My guess would go in four ways:
- the rubber sprocket inserts are gone
- The rear wheel bearings, but that would probably go in combination with riding noise.
- The rear wheel bridge (or whatever it is called in english) bearings have play.
- The front steer bearings have play.

Good luck and let us know.

 

My thought as well... and easiest to check and/or replace!

 

It appears it is something with the cush drive. Almost like it is totally gone. I put it on the stand and in gear. Starting to move the wheel figuring it would have a little play...yeah - I measured how far the letters on the tire moved. 7 full inches! At this point I thought that maybe I put it in the wrong way but that is an awful lot of movement since each section is like an inch wide.

I haven't torn it down yet because I might actually need it tomorrow for transportation. I will post more as soon as I get it apart.

 

Took the wheel of and sure enough not one piece of rubber where the cush drive goes. Almost like I lost it.

 

Just be real easy on the clutch!