Vibration in grips at 3k-5k RPM...any way to correct?

[Chris Wilson]

Rubber mounting is the 'go to' here, the Bellagio has large rubber grommets inserted into the top triple tree and it works well.

The key is here as Docc says to to reduce the source or post engineer it with isolation.

Isolation usually involves the transmission of the vibration through a material that has its harmonics at a different level than the source and thus it absorbs rather than resonates.

Its a long path between the source ( crank wieghts) and the where its metered (the bars) and surely someone smarter than me could think of someting along that path that may help.

If not, Gel filled Bars anyone?

Chris.

[docc]

IMHO (as well as experience), the factory "stalk" mirrors are aggravating contributors to the handgrip vibration on the Sports, mounted just inboard of the grips and extending a "pendulum" superiorward significantly.

Pretty sure no one ran that past the NVH Engineering Department . . .

 

 

[VtwinStorm]

1 hour ago, docc said:

IMHO (as well as experience), the factory "stalk" mirrors are aggravating contributors to the handgrip vibration on the Sports, mounted just inboard of the grips and extending a "pendulum" superiorward significantly.

Pretty sure no one ran that past the NVH Engineering Department . . .

 

 

Pretty sure my mirrors aren't stock. I have never seen them in any factory photos of a V11...No idea what they are from.

[docc]

11 minutes ago, VtwinStorm said:

Pretty sure my mirrors aren't stock. I have never seen them in any factory photos of a V11...No idea what they are from.

IDK, bud. These look like the stockers ("stalkers?!?" ) to me . . .

Reference images:

 

[VtwinStorm]

27 minutes ago, docc said:

IDK, bud. These look like the stockers ("stalkers?!?" ) to me . . .

Reference images:

 

Hmmm...they really photograph differently. Mine aren't matte finish...but very glossy, almost wet looking. Also, not so rounded, but pointy.

I'm just imagining things I guess. Anyway, stock mirrors work great for me.

Just need to iron out the vibration in the hand grips.

[docc]

9 minutes ago, VtwinStorm said:

Hmmm...they really photograph differently. Mine aren't matte finish...but very glossy, almost wet looking. Also, not so rounded, but pointy.

I'm just imagining things I guess. Anyway, stock mirrors work great for me.

Just need to iron out the vibration in the hand grips.

Yep, I see the difference with your glossy mirrors. Just saying they might be amplifying the vibration. And harshness. Noise? That could just be me . . .

[VtwinStorm]

3 hours ago, docc said:

Yep, I see the difference with your glossy mirrors. Just saying they might be amplifying the vibration. And harshness. Noise? That could just be me . . .

No strange noise... machine sounded great before her major service.

Perhaps I should get a set of Napoleon bar end mirrors after all...

[po18guy]

One more suggestion: OURY street grips. They are a block pattern, made of low durometer (soft) rubber. I use them on parallel twins with good effect. Mountain bikers use the MTB version to cushion the shock of dirt riding. Less than $15 on Amazon.

[motortouring]

5 hours ago, po18guy said:

One more suggestion: OURY street grips. They are a block pattern, made of low durometer (soft) rubber. I use them on parallel twins with good effect. Mountain bikers use the MTB version to cushion the shock of dirt riding. Less than $15 on Amazon.

It even looks like they have a special ribble part for the throttle assist

 

 

 

[Chris Wilson]

Would it be possible to insert a dampner inside if the frame front down tube?

I know it sounds daft  but it's the main  route for vibration  from engine to handle  bars.

Just thinking  laterally here.

[VtwinStorm]

1 hour ago, Chris Wilson said:

Would it be possible to insert a dampner inside if the frame front down tube?

I know it sounds daft  but it's the main  route for vibration  from engine to handle  bars.

Just thinking  laterally here.

Is there even an opening there? I know the tubes are, well hollow, but I thought it was welded shut?

Don't have my V11 in front of me...

[po18guy]

On 12/27/2021 at 6:41 AM, Pressureangle said:

I have about 5 pounds of lead shot I was going to put in the bars on the '85 LeMans, but after the engine work the vibration went away and it wasn't necessary to try out. Might give it another go in my '74 Aermacchi this spring tho.

Reading through the thread, I remember seeing this exact method used on some other paint-mixer bikes. Perhaps a rubber plug driven into the bar to a certain depth and then just fill the void with shot. Easy enough to alter the weight or undo. You want to change the harmonics of the bars at their ends and adding weight is the crude but effective way that even Honda have used.

I ride my bike mostly 120kph on the freeway/interstate/motorway and 4K and above is a sweet spot. I have neuropathy in my hands and I would most certainly note any increase if the bars were a problem.  The "Occam's Razor" method might be to switch to soft grips (Remember "Grab-On" foam grips in the 80s?)  and attach much heavier bar ends.

The caveat in my experience is that I have the OEM tapered (28mm > 22mm) high mount alloy bars which possess their own harmonic, plus Ken Sean folding bar-end mirrors (cheap but effective). I did have to fab up some Delrin bar inserts, since those which came with the mirrors were overly soft.

[Lucky Phil]

2 minutes ago, po18guy said:

Reading through the thread, I remember seeing this exact method used on some other paint-mixer bikes. Perhaps a rubber plug driven into the bar to a certain depth and then just fill the void with shot. Easy enough to alter the weight or undo. You want to change the harmonics of the bars at their ends and adding weight is the crude but effective way that even Honda have used.

I ride my bike mostly 120kph on the freeway/interstate/motorway and 4K and above is a sweet spot. I have neuropathy in my hands and I would most certainly note any increase if the bars were a problem.  The "Occam's Razor" method might be to switch to soft grips (Remember "Grab-On" foam grips in the 80s?)  and attach much heavier bar ends.

The caveat in my experience is that I have the OEM tapered (28mm > 22mm) high mount alloy bars which possess their own harmonic, plus Ken Sean folding bar-end mirrors (cheap but effective). I did have to fab up some Delrin bar inserts, since those which came with the mirrors were overly soft.

So your bike doesn't have the std bar weights?

Ciao

[po18guy]

18 minutes ago, Lucky Phil said:

So your bike doesn't have the std bar weights?

Ciao

They're in the spares box now. Came with them, but it seems that the bar-end mirrors have assumed their function.

[Lucky Phil]

5 minutes ago, po18guy said:

They're in the spares box now. Came with them, but it seems that the bar-end mirrors have assumed their function.

So have you looked at the size, weight, design and dimensions of the std bar weights? Do you think the factory spent some time and effort to tune them to the specific requirements and find the best compromise? Do you think slapping on a set of bar end mirrors and Delrin end caps will achieve the same outcomes with regards to bar vibration?

These are the sort of questions you need to ask before embarking on other home brewed solutions to problems that may not exist.

Ciao