Why does my 2009 Fatboy vibrate my feet off th running boards. I tried shifting into 6th gear at around 65-70 and I got my feet shaken off the boards.
5th gear is fine with little vibration. Seems the engine is turning too slow and the power stroke is causing the vibration.
Bike is new to me.
What's up?

 

I'd check engine mounts 1st, then at worst case you're counter
Balancers might not be working. Check exhaust bolts too.

 

What mileage what add ons?

 

softtails are solid mount to the frame. hence the balance shafts. possibly old style or bad compensator, eng running to lean or too low of an rpm.

my 07 fb always has had a buzz to it around those speeds..

hell it may have a BDL springless comp in it.. now that made my bike vib bad, I mean bad... pure junk..

 

My '13 Slim feels like that in 6th too, but that sounds a little slow for 6th gear.
I won't even use 6th until around 75mph... above 3000 RPM it starts to smooth out again but by then you're passing Porsches on the Autobahn...

 

My 09 Heritage did the same thing.
People always kept telling me that it was normal.

However I couldn't help to think that if having a vibration so violent that it caused your teeth to chatter is normal, Harley wouldn't be able to give softails away.

Then one day I realized that the vibration was gone.
As far as I can tell the only thing I had done was changed fluids, changed tires and upgraded the shocks, so it had to be one of those three that fixed the vibration.

I just got back a couple of weeks ago from a 500 mile ride where-as 400 miles of it was 75-80 mph.
The ride wasn't as smooth as a Caddy, but certainly well within comfort range.

I've since changed fluids and the rear tire so I think my problem was probably either the front tire or the shocks.
I don't know if your problem is fluids, tires or shocks but that's my story.

 

Thanks all for the comments. I have a 2009 Fatboy with 20,000 miles, stage one with screaming eagle tuner. I had the bike dynoed as it was running to rich. I do not have Dino paperwork in front of me but it was well better then stock and better when the retuned it. Seemed like a new bike. I had not been doing any interstate travel so I was in the 65 range and newer ran any distance in 6th gear.
Not sure why 5th gear is smooth and 6th is $hit.

 

By the way I am running royal purple and the pink stuff in the transmission. Forgot the name. After I put the pink stuff in I could find neutral for the first time at a red light.

 

That's exactly were my symptoms as well so I just kept it 5th because I couldn't stand it in 6th.

 

75 mph is 120 kph. The maximum speed limit on highways in the Netherlands is 130 kph / 80 mph. I've been on the Autobahn doing 160 kph / 100 mph and have been passed by cars that made me look like I was sitting still.