Stelvio Handle Bar Vibrations Cause

[canuck1969]

Been battling a vibration on the Stelvio between 3400 and 4000 RPM. Balanced the TB's several times. Even had the dealer balance them just to make sure. Checked the plugs and plug wires. Everything checked out but the vibrations/rumbles were still there. Spoke to some people and they said it was normal, spoke to others and they said they did not notice it on theirs and others just said it is what a Guzzi does.

Did some long rides over the last couple of weeks and was getting tired of it. Could thottle around them through gearing but not my idea of a solution. Was always in the same RPM range.

Since the vibrations where not tuning related, must be caused by something mechanical. My last bike was a KLR and I battled a similar vibration, ironically, around the same RPM band. On the KLR it was becuase of the new engine guards that I had put on. They were bolted in three spots, one on the engine, one on the pegs and one on the subframe. This configuration cause vibrations because it actually held in the vibrations of the engine and transmitted them throughout the entire bike. Solution here was to disconnect the connection to the pegs and vibrations were gone.

So I took a shot in the dark and removed the engine crash bars. The vibrations are now gone in the bars. Night and day when riding. Mirrors are steady during that RPM band and no more rummbling. The bars are attached to the engine block in two spots and the rear engine mount to the frame. Must be causing a resonance through the bike similar to the KLR.

I did notice that when I took them off the bolts were not that tight. This may have been the cause, but for now I am leaving them off. When I get time I will put them back on with some rubber spacers.


Just glad I am able to ride again with a smile on my face :woohoo:

 

[northernguzzi]

should have bought a beemer lol if you didn't vibes - 4500rpm in 5th gear is the sweet spot on my NTX - only use 6th to pass in tight situations. Guzzi don't like to be lugged - besides at that RPM is where your power band starts to peak. Most all vibrate in the first 4000k and level out pretty nice thereafter. You won't have this bike broke in until 20,000k - its a V-twin - comparing it to KLR's is like comparing apples and grapes - but you made the right choice and parking the KLR and hoping on the NTX.

 

[canuck1969]

Update on the bars. Put them back on last night and anti seized and retightened all the bolts. The only spec I had was the rear engine mount bolt which was 50 NM. For the engine mount bolts I started at 18 ft-lbs but gave it a bit more. Not sure what the resultant was but it was a hell of a lot tighter than they originally were. For the lower engine/skid plate bolts again, went with wrench tight. Will try to get a final torque spec once I am done playing.

The results......the vibration/rumble I was experiencing is gone. Looks like it may have just been under torqued bolts. As for the lights, once they go back on I will try some rubber mounts to try and preserve them for a bit.

 

[boxermoose]

Update on the bars. Put them back on last night and anti seized and retightened all the bolts. The only spec I had was the rear engine mount bolt which was 50 NM. For the engine mount bolts I started at 18 ft-lbs but gave it a bit more. Not sure what the resultant was but it was a hell of a lot tighter than they originally were. For the lower engine/skid plate bolts again, went with wrench tight. Will try to get a final torque spec once I am done playing.

The results......the vibration/rumble I was experiencing is gone. Looks like it may have just been under torqued bolts. As for the lights, once they go back on I will try some rubber mounts to try and preserve them for a bit.

Handle bar bolts are something you might like to use blue loctite on - rather then anti-seize

If you torqued them to spec with anti-seize on the bolts then they are probably 25-30% over torqued as manufacturer specs are typically spec'd dry - unless otherwise specified

 

[northernguzzi]

Here is a tip for torque settings that are not listed in the service manual. Before undoing the bolts take your torque and get a setting by dialing up your wrench until it hits the foot pounds. I had to do that with the front and rear wheels before changing my tires as I couldn't locate a torque setting in the service manual. Then I went 10% over.
I set the rear wheel bolts at 85fps each.
Anti-seeze has allot of copper and moly for friction wear in it and prone to loosening under vibration -lie using wax paper between to slabs of frozen meat -- easy to separate. best go with the loctite.

 

[canuck1969]

Update on the bars. Put them back on last night and anti seized and retightened all the bolts. The only spec I had was the rear engine mount bolt which was 50 NM. For the engine mount bolts I started at 18 ft-lbs but gave it a bit more. Not sure what the resultant was but it was a hell of a lot tighter than they originally were. For the lower engine/skid plate bolts again, went with wrench tight. Will try to get a final torque spec once I am done playing.

The results......the vibration/rumble I was experiencing is gone. Looks like it may have just been under torqued bolts. As for the lights, once they go back on I will try some rubber mounts to try and preserve them for a bit.

Handle bar bolts are something you might like to use blue loctite on - rather then anti-seize

If you torqued them to spec with anti-seize on the bolts then they are probably 25-30% over torqued as manufacturer specs are typically spec'd dry - unless otherwise specified

This was the crash bars not the handle bars....

As for the anti seize....I used a wet torque spec for an M10 bolt so not worried about overtightening. My experience with loctite on a hot engine is it does not do much. I would rather take my chances with it loosing up when bolted to the hot engine block then seizing in there and never getting them out. They originally had anti seize on them from the factory. Perhaps that is why they loosened up a little. I just add it to my maintenance list to re-torque.

 

[WayneOrwig]

I anti siezed mine. I have checked a couple of times and they have not loosened in 34,000 miles.
I don't even want to think about them corroding in place. That would be a big problem. I would prefer a bolt coming loose versus a bolt freezing to the block.

Pretty odd how the crash bar would have much impact on the handlebar vibs.

 

[canuck1969]

I anti siezed mine. I have checked a couple of times and they have not loosened in 34,000 miles.
I don't even want to think about them corroding in place. That would be a big problem. I would prefer a bolt coming loose versus a bolt freezing to the block.

Pretty odd how the crash bar would have much impact on the handlebar vibs.

Thanks for the feedback Wayne.

Crash bar vibs are pretty common especially when mounted to the engine. On my KLR we used to call them tunning forks as that is exactly what they looked like when they got going. Heard it happening on V-Stroms with GIVI bars also. Every bike is different. Best theory I could come up with is that the bars held in the vibrations of the engine by adding another ridged point to the frame. They are usually bolted in a triangle pattern for optimal strength, but also optimal rigidity. In stead of the vibes disipating into the air, they are redirected back into the bike. The looser they get, the worse it is. If you tighten them up enough you can usually change the resonance enough to make it not as noticable. Worked on the Stelvio, but not on my KLR. Had to eventually disconnect one of the mounting points on the KLR to "free up" the vibs and it smoothed right out. There is still a slight vibe on the Stelvio compared to no bars but the resonance is now in the acceptable range.

 

[Glenn Yingst]

Canuck I was just searching for a solution to the same problem. Glad I read your post. My bike goes in next week for its first service. when it gets back I will be getting after that pesky handle bar vibe. Did you try the rubber spacer thing?

 

[canuck1969]

Canuck I was just searching for a solution to the same problem. Glad I read your post. My bike goes in next week for its first service. when it gets back I will be getting after that pesky handle bar vibe. Did you try the rubber spacer thing?

As you can see that post was from a couple of years ago and 50,000km earlier.

Handlebar vibes are pretty common. Although the crash bars seemed to help that was not the cause of the vibes. The stelvio is a viby bike and you can only control what can make it worse.

1. TB sync is usually the main suspect. The 8v is very sensitive to it and like it perfect so make sure they check it on your first service. Tell them that you get a lot of vibes and complain about it. If you tell them to just check the sync some dealers will charge you for it. If you tell them that the vibes are bad they should do the sync under warranty.

2. Valve gaps can cause a vibe. This should be part of the first service. Same comments as number 1.

3. Motor mount bolts under the tank. Although mine were fine some did report that there's were loose.

Failing all the above everything else is normal. It will get better with miles as they are not normally broken in until at least 10000 km.

You will probably fine the worse around 3500 to 3750. Normal as that seems to be the natural resonance of the bike. Again it will get better with age and the 3 items above.

What i did the on mine to completely eliminate the vibes was to put about 5 lbs of lead shot in the bars and added a pair or Rox risers. The risers helped more than the shot not to mention improved the riding position tremendously. Highly recommended if you feel you are reaching for the bars. I have a Corbin on mine which pushed me back a little further and made my peoples worse.

Let us know how the first service goes. Everything you are experiencing is normal Guzzi growing pains. Like a fine Italian wine it does get better with age.

 

[tecpatl4]

I also had the same thing. Syncing the throttle bodies helped some. I just checked all the mounting bolts. On the bottom there are two bolts, one goes through the mount for the bash plate, but the one right next to it was loose. I was able to turn it one handed with a tiny 1/4 inch ratchet. So I snugged them and there was a big improvement.

 

[John Warner]

All this talk of things coming loose, am I the only one here that's heard of Wire-Locking?

 

[tecpatl4]

I also added some highway pegs someone gave me, they probably weigh 2 pounds apiece as they are from a Valkyrie. I expect that changed the resonance of the bars too. I will replace them with black once I decide if I like having them or not.

 

[buster001]

I also added some highway pegs someone gave me, they probably weigh 2 pounds apiece as they are from a Valkyrie. I expect that changed the resonance of the bars too. I will replace them with black once I decide if I like having them or not.

Pictures Please
Thank You
David.

 

[Stelltoid]

Been battling a vibration on the Stelvio between 3400 and 4000 RPM. Balanced the TB's several times. Even had the dealer balance them just to make sure. Checked the plugs and plug wires. Everything checked out but the vibrations/rumbles were still there. Spoke to some people and they said it was normal, spoke to others and they said they did not notice it on theirs and others just said it is what a Guzzi does.

Did some long rides over the last couple of weeks and was getting tired of it. Could thottle around them through gearing but not my idea of a solution. Was always in the same RPM range.

Since the vibrations where not tuning related, must be caused by something mechanical. My last bike was a KLR and I battled a similar vibration, ironically, around the same RPM band. On the KLR it was becuase of the new engine guards that I had put on. They were bolted in three spots, one on the engine, one on the pegs and one on the subframe. This configuration cause vibrations because it actually held in the vibrations of the engine and transmitted them throughout the entire bike. Solution here was to disconnect the connection to the pegs and vibrations were gone.

So I took a shot in the dark and removed the engine crash bars. The vibrations are now gone in the bars. Night and day when riding. Mirrors are steady during that RPM band and no more rummbling. The bars are attached to the engine block in two spots and the rear engine mount to the frame. Must be causing a resonance through the bike similar to the KLR.

I did notice that when I took them off the bolts were not that tight. This may have been the cause, but for now I am leaving them off. When I get time I will put them back on with some rubber spacers.


Just glad I am able to ride again with a smile on my face :woohoo:

Canuck,
just tightened the bolts holding the crash bars. Took it for a blast - man what a difference.
No more sleepy fingers on my right hand.

Thanks Dave

 

[canuck1969]

Excellent Dave. Glad to hear it worked out.

 

[tecpatl4]

I took the highway pegs off pretty quick, they were ugly chrome things off a Valkyrie. I only put them on to see if I wanted them, I'll pick up some black ones in the spring. But still the vibration is a lot better since I tightened the bolts.

 

[canuck1969]

I took the highway pegs off pretty quick, they were ugly chrome things off a Valkyrie. I only put them on to see if I wanted them, I'll pick up some black ones in the spring. But still the vibration is a lot better since I tightened the bolts.

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