I would put my money on a frame to engine clearance issue.
Had it on my 05 Road King when I fitted aftermarket passenger pegs.
All looked good but the teeth rattling,vision blurring jackhammer started at 2500 through to3500rpm.As in your case my wife felt it the most! Took the pegs off and there was peace in the land.
There was clearance when it was idling but under maximum load the engine was moving back.Shaved off an 1/8" from the edge of the peg and enjoyed that bike for another 5 years.Really don't think the factory could let your bike through with a mistimed balancer?Let your dealer sort it and enjoy your great bike!

 

The troll stench is coming through the monitor.
The M8 platform is smooth as butter, buy one, you'll find out.

 

I agree, mine is nothing but smooth. I keep rear psi at 40 and front at 36. Have never felt any vibrations or shudder.

 

You should read a whole thread before jumping in.
The threadstarter already bought anM8 and it vibrates.
So far we have only seen positive and helpful suggestions?

 

My apologies Oldskewl. Took my own advice and re read the entire thread.
It has gone way off topic and some threads make you wonder why they waited
until now to bring up unresolved problems?

 

Makes no sense.

 

Yeah, I read the whole thread from the start and really it stuck to topic better than most. As for as a troll, the OP took his bike to the dealer and is pretty happy with the outcome, trolls don’t do that.

Does look like there’s some widespread problem with the motor mount alignment and torque, and in your case breakage.

 

On my shovel if I wanna see what's in back of me I gotta wait until the mirror spins 360 degrees before i get a quick glimpse of what's there. Usually all I see is my smile.

 

Yea they had a habit of working loose didn't they, ahh the good/bad old daze.
Everything rattled or buzzed but ya knew what it was most of the time.If it stopped though that freaked me out till I worked out what it was, if it had fallen off or stopped working .

 

I just started having this high speed vibration on my FLTRU it doesn't seem to be rpm related . around 70 it gets worse and by 80 really nasty. I put bike in 4th gear and ran at same rpm as in high but had almost no vibration think its a balance or tire issue as I feel it in bars the most. anyone else still having this issue?