I have a 2012 flhx it has a bad vibration around 1700-1800 rpm shakes the the mirrors windshield real bad dealer says it normal but I can't find anyone who's bike does the same HELP

 

You're lugging the motor. The only time your bike should see 1700-1800 RPMs, is as you accelerate through it into the operating RPM range, which starts around 2500. Otherwise, you need to downshift a gear.

 

2nd on your lugging lugging

your going to twist the crank doing that

 

Like the others move through that range and get to a cruising range on rpm for the gear you are in. Pressed cranks do not like to be lugged. If you are seeing that much vibration imagine the harmonics in that engine.

 

It's when down shifting I have let me also say I've been riding hds for 15 years this my 5th one last one was a 2010 flhx and I've taken at least 5 other fls out and none of them do the same

 

I don't have that model or year of Harley. I also don't cruise at that rpm. I also don't downshift except to be in the right gear if I need to accelerate. I don't use much downshifting for engine braking. I know that staying in a harmonic situation will end up causing problems. All vibrations are harmonics. Someone else may have a better answer to your problem.

 

I don't have your bike or model, either. I downshift a lot and 2000 is the absolute lowest rpm I will downshift at, usually a little higher than that. The motor will hit 1500 as I'm slowing down to an idle, that's the only time it will see that range unless it's accelerating from a stop.

 

Nevil thats when it happens slowing to a stop or like you say taking off

 

I had a bad motor mount on a 06 Strt Glide and it did that too. A new mount and it was back to normal. not sure otherwise.. ??

 

Guess anything is possible it only has 1k on it and the dealer said they checked the mounts