I was on a 100 mile trip today and noticed an unusual vibration in my bike above 60mph. It has always has some vibration at highway speed but never to the point that I could barely keep my feet on the floorboards. This felt more like a strong buzz throughout the frame, Maybe I was hyper-sensitive to it today but I don't think so. I've checked the tires and for any loose bolts. Engine is running great so I don't think it is s miss. What else should I check?

 

I would note at what rpm above 60 you have that vibration and then try to replicate it in all the other gears at that rpm. If you can not then I would think that it would eliminate the engine. From that point I would check trans fluid or possible your 5th gear output shaft bearing, rear belt tension or wheel bearings.

 

Buzzing through the frame I'd check motor mounts first.

 

Didn't THC post some time back about this same thing tracking back to perished rubber isolators in the floorboards themselves?

 

What I feel is kind of all over. Floorboards and seat mainly . So, there is the front engine mount that is rubber. I guess the other mount to check is the top engine mount? It's a rigid mount to the frame right? I guess just check for tightness? I guess the tank has to come off for that .

 

Did you try pulling the clutch in and coasting to see if it goes away?

 

No, but thats a great idea. I'll try it tomorrow . Thanks

 

The front engine mount would be favourite for causing vibration. When they pack up the bonding between rubber and steel sleeve fails. The upper mount is not rigid, but is mechanical with a swivel at each end. It would be very unusual if it causes any problems.

I explain what that does in my bagger wobble thread.

 

If either of the stabilizing links have become frozen, the motor will vibrate

 

It did on my bike at least.