2018 Fat Boy Vibration

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Oct 20, 2017 | 01:19 PM

#61

TORQUEY

Seasoned HDF Member

Joined: Aug 2010

Posts: 5,173

Likes: 177

From: East Coast

^^^WOW. Can't even guess, unless that's the way they all are. I guess I'll be finding out soon...

Oct 20, 2017 | 01:31 PM

#62

Thingfish

Grand HDF Member

Joined: Jun 2010

Posts: 4,584

Likes: 918

From: coast to coast

Quote:

Originally Posted by dusty1300

I was expecting vibration... the fast frequency buzzing in the bars and maybe floorboards or seat. What I wasn't expecting is the entire bike seems to shudder ( I don't know how else to describe it), when I hit the gas. Big shaking, clunking, and other noises. But not the kind of vibration you would try to reduce with grips, bars, etc. That would have no impact on this.

I might try to record it, maybe it would work.

I'll post it here if I can get it. First I need some nice weather.

Tom

Every time you describe it I think something must be out of whack.

Mine feels like power pulses/throb of the motor...feels solid and well built. Even when you get it sorted you shouldn't have high frequency buzzing, but by 3900rpms+ the power pulses certainly get more pronounced with a little more edge to it.

Oct 20, 2017 | 01:32 PM

#63

Matt990724

Road Master

Joined: Aug 2010

Posts: 950

Likes: 19

From: Southcentral, OK

Maybe swap bikes with your wife. I am thinking the vibrations might not "bother" her as much.

just thinking out of the box.

Oct 20, 2017 | 01:42 PM

#64

Thingfish

Grand HDF Member

Joined: Jun 2010

Posts: 4,584

Likes: 918

From: coast to coast

"Clunking and other noises" doesn't sound great.

There is some gear whine, but clunking....not so much.

You're not just describing how it feels winding it up to 4500 - 5000 rpms right? You're talking about 2500 - 3500? Think you mentioned this earlier, but just checking.

Nov 3, 2017 | 01:15 PM

#65

thessler3

Stage III

Joined: Nov 2017

Posts: 3

Likes: 0

From: NJ

V-twin vibration

Quote:

Originally Posted by dusty1300

Having owned more than 2 dozen bikes in my life, for the first time I find myself on a Harley. I heard about the dual counter-balancers, mono-shock, and went to look at one and loved it.

So I bought it, wasn't allowed to drive it first, but took it on faith that it would be as described by many.

So, here I am, hating the 114 engine. It vibrates something awful. Any twist on the throttle and it shakes really bad. On the highway, anything over 2k rpm and my glasses shake so bad, I can't read road signs. I can't imagine ever taking it above 4k, it would be horrible.

Under power, it feels and sounds like a 4 cylinder or 6 cylinder car with one cylinder not firing.

For a while, as I was waiting for a windshield to arrive, I put some of this vibration on the wind. Now I have one, and I notice it much more.

Here are two people's opinions on this from other threads:

"Local dealer had 2018s for test rides today and I decided to try the 2018 Fatboy 114. Wow the engine had lots of power but I couldn't believe the vibrations coming from the engine. It was really shocking. For a counterbalanced engine I was surprised. Almost felt like my fillings would come out."

"I have zero vibration in my new fatboy just did a 100 miles and it is smooth as can be. That bike is like a caddy lol."

My impressions are like the former quotation.

So, is there something wrong with mine and apparently others? Can it be fixed, or is this just the worst engine I have ever driven?

I would sincerely appreciate opinions and/or suggestions.

Tom

Harley uses Harleyspeak when talking about counter balancers being used to cancel vibration. In fact, rotating counter balancers can never completely cancel reciprocating vibration from pistons moving up and down. Cancelling primary vibration completely on a v-twin is not feasible, even with two counter balancers as the piston motion is in two planes separated by 45 degrees. Twin counter balancers were invented by a Dr. Lanchester back around 1900 and are often used on in-line 4 cylinder engines that have very bad secondary vibration (twice engine RPM - buzzy) . Without going into the physics, I will state that neither the primary or secondary vibration can be completely cancelled out on a 45 degree V-twin Harley. The V-rod motor is the smoothest Harley I have ridden - it has both counter balancers and rubber mounting. So Harley says they "chose" not to completely cancel the primary vibration on the new touring bikes. What they should really say is that it is impossible to completely cancel reciprocating vibration with rotating counter balancers. The M8 touring bikes are a step in the right direction, with a single counter balancer and rubber mounting. Way to go. Note that BMW boxer twins also do not have perfect primary balance as the rod journals on the crank are an inch or so apart and that creates a rocking motion and some vibration. Only the Honda and BMW six cylinders are truly smooth with no counter balancers or rubber mounts.

Nov 3, 2017 | 01:44 PM

#66

Thingfish

Grand HDF Member

Joined: Jun 2010

Posts: 4,584

Likes: 918

From: coast to coast

Quote:

Originally Posted by thessler3

Very well explained. Also exactly why I love my R9T boxer and Harley with their accompanying vibes. Too smooth can feel like an appliance on a bike. In any engine you tend to feel some feedback at higher operational levels...I'd rather feel the power pulse of a v-twin (transverse or otherwise) most of all followed by opposed twins...then singles, triples, v-4 like the VFR Inteceptor...then I'd jump to V8 cars.