First time I replaced the rear tire for my GS, I didn't take the sprocket off. I was wondering why there were so much balancing weights. Now it was time to replace the tire again and the sprocket fell off. (I've thought, that the sprocket is attached to the rim, not to the drum as it turned out)

Then I started to wonder what are the rubber parts inside of the rim. And why there are only two of them! So, there was three rear hub shock absorbers (64651-27A01) missing.

What kind of damage could it have made?

My best guess (Addiasguy will correct me) is that the chush-drive protects the chain, sprockets, and wheel from the sudden torque changes from shifting gears and accelerating hard.

When you screw-on the throttle, the chain suddenly pulls hard on a heavy wheel which, for a fraction of a second, isn't ready to move yet. If the front sprocket, chain, rear sprocket and wheel were a true metal-on-metal direct drive, the constant acceleration, pulling tugging, and engine-breaking-yanking would wear out the chain and sprockets much faster. It would also make riding harsher.

Brian is right. In adition, they help keep the cush drive in the right position.

Are you sure 3 are missing? Sometimes they stick to the cush drive (sprocket holder thing) and sometimes they stick to the wheel hub.

You do want all of them in there. They are important.  They are also cheap to buy.

I'm sure, there were 3 missing and I ordered new ones. Average temperatures here are still under freezing point, so it will probably took few weeks before I can really start the season. Hopefully i get the parts before the roads melt.

Another question: I haven't been there watching, when the mechanic balances the wheel. Is it possible to do with the sprocket on or should it be done with it?

My shop balances wheels with brake rotor on.
Cush drive is not on.

Ok, thanks!