Just got my Fat Bob 114 last Friday, took it for its inaugural 50 mile run on Saturday, and noticed what seemed like a LOT of vibration, certainly way more than I was expecting. Searching through the forums here I've seen a couple other people mention it.

At idle, my Bob shakes and rattles like what I'd expect from a vintage Harley. Then it gets smoother as the revs climb, up to about 2,000 RPM where it's glass smooth and I'm very happy with it. But once it hits about 2200, vibration comes back and grows worse and worse as the revs climb. By the time I hit 3000 it's what I'd call pretty bad; for comparison my prior bike (a Street 750) was much much much much smoother than this. I definitely wouldn't want to ride this bike for any substantial distance with this level of vibration.

I'm taking it back in tomorrow (dealers are all closed on Sunday and Monday around here), but before I do, I just thought I'd ask if others thought this sounded normal or am I expecting too much?

I read and watched lot of reviews before deciding on the Fat Bob, and in just about every one of them they mentioned the lack of vibration as a major improvement over prior generations. Here's a sampling of quotes:
From Harley's own website:
(note: at idle is when my engine is lurching around the most. I originally wasn't that troubled, until I read here that they say specifically that it cancels out vibration at idle.) So how's your 114 at idle?

Motorcycle.com said:
. If mine was smooth up 'til 3500, I'd be thrilled with it, but it's only smooth 'til about 2200. I mean, they're saying "some vibration enters the pegs and grips"; I'm saying on mine that it's aggressively vibrating the whole bike at 2500+. Does that track with others' experiences?

webbikeworld.com said:
Now, that makes me pretty sure that mine has an issue. I couldn't get anywhere near highway speeds in 4th without it being extremely buzzy. I haven't taken mine above 3,500 rpm yet (only 50 miles on it so far) but it's very buzzy at 3,500. Uncomfortably so.

Then there was this review on YouTube, from a guy who usually rides a 2017 Low Rider S, but documented his first ride on the Fat Bob 114:

At about 9:21 he does what looks like an aggressive acceleration run; he blurs out the speedo and tach so we can't see what he's doing but it sure looks like he gets it up to 5,000 rpm or more. And at the end he just laughs in delight and says:
I looked in the owner's manual under "troubleshooting" (page 170) and it mentioned a few things to check for Excessive Vibration, including front engine mounting bolts loose, or engine to transmission mounting bolts loose; I'm hoping that they can check those and clear this up.

I'll report back on what they say; I'm just dreading them saying "tested, no problem found". I guess I'm looking here for feedback from other M8 owners, especially 114's, to verify if what I'm expecting is reasonable. Thanks!

 

Sensitivity to vibration is subjective, but I'd say it sounds off to me. One thing all M8s seem to have in common in the vibration department is dead smooth idle. For me pleasant vibes start around 2200, then build but are perfectly fine imo to about 3650 (about 100mph in 6th) for extended riding. Getting into the 4000 - 5500 range is fun to visit for aggressive throttle workouts, but not my hangout place.

If the dealer says it's "normal" ask to ride a different bike to feel for yourself. Maybe the counterbalancer is misaligned?

 

I've had zero similar vibration issues on my FB (compared to what you describe above). It's smoothness is one of the things I love so much about the bike.

 

Sounds off to me too.

The bike should not be vibration free - but it should be pretty damn smooth. As a test, let it idle and put your gloves on the seat. If they stay put, it's fine (at idle), if they fall off, then you have a problem.

It's also subjective. Have you ridden any other big twin Harleys before? If so, the bike should feel way smoother than a Twin Cam Dyna at almost all rev ranges.

If you are looking for Prius smooth, then you are looking for the wrong thing. The bike should have some vibration, but certainly not much at all at idle. The mirrors shouldn't be bouncing around for instance.

My 2018 114 Fat Bob is extremely smooth throughout the rev range compared to my Dyna. But as you get up through the revs, the vibrations do increase as you would expect from such a big engine. However - I can happily ride around at all speeds up to the red line without any excessive vibration. Don't get me wrong - there is some vibration, but it's extremely well controlled for a huge motor solid mounted to the frame - counterbalancers or not. But then HD tuned it to eliminate primary vibration and there is no way you can ever eliminate all secondary vibration.

It SHOULD vibrate a bit when you really crank the throttle. Too much reciprocating mass to do otherwise, but it certainly should not feel bad. Just the power of the engine throbbing away underneath you.

I think there is something wrong with your bike.

As others have said - take it back to the dealer and try some other 2018 softail for comparison.

 

Sounds like you're all in agreement...
Yep, that's the plan for tomorrow.

Thanks all, and hopefully it'll just be a minor thing that they can tighten up or whatever. Frickin' love the bike in every other way; if they can get it smoothed out then it'll be perfect.

 

It's definitely not dead smooth, I can see the whole bike shaking a little, the mirrors are definitely blurry and the speedometer is hard to read at idle.

Glove test completed. I put one glove on the passenger seat, one on the rider seat. I let it idle until it warmed up, once the revs were down to around 850 it threw the passenger seat glove off.

So, yeah, it sounds like mine isn't performing as it should -- which is bad news, but also good news, in that hopefully this bike will now be able to be made even better once they figure out what's causing it.

Thanks all for your responses!

 

It's only smooth during cruising speeds. If you exercise the engine the vibes are pretty bad. Almost hand numbing. If you keep the bike in the upper rpm range then you will feel it. Everyone has different sensitivity to vibes and I am one of them.

 

bikes vary for sure + tolerances come into play as well as poor assembly. my 06 1200 sportster engine vibrates a LOT but bing fully rubber mounted little gets thru @ any rpm. i test rode a preowned 13 victory hammer 106" of super smooth solid mounted engine!!! todays technology allows manufactures to tune aka build engines as smooth or not as they want!!!!

 

Well... took it in, they said "nothing out of spec, nothing excessive." But they kept it for an hour... at one point they had me fill in name & address on a service form, so -- it seems to me like they did *something* and billed it back to Harley under warranty.

When I got it back, it was better. They insist they didn't do anything other than make sure everything was tightened properly, but still -- it's definitely better. I put a hundred miles on it today; it seemed better at the start and not as great at the end. Oh well. Still buzzier than I'd like, but it doesn't get truly bothersome until about 3500 RPMs where the seat is actively buzzing. If I had to guess, I'd say the handlebar ends are moving through a range of at least a good 1/4"or more at that speed. But, as long as it's clean up to 2500-2800 RPMs, it's fine. A tight grip tones down the vibes, but that gets tiresome after a while too... So I'm off to Revzilla to order a set of Kuryakyn ISO grips with bar end weights. That should tame the buzzes down to acceptable, and I can get on with enjoying this magnificent ride.

 

I test rode several of the 18's at a dealer a couple weeks ago and all the bikes 107 & 114 were dead smooth. Reminded me of riding a metric cruiser.

Although I really like the way my twin cam feels, if your M8 is feeling similar, there is definitely something wrong with it.