Pulsing vibration

My '03 VFR800 has developed a pulsing vibration when moving over 120km/h. It is more intense the faster I'm moving, and it's difficult to tell where it's coming from.

I'm just looking for ideas; I'll be looking at neck and wheel bearings, and fork clamps to start. Any other suggestions are welcome.

 

First :welcome: to the madness :wave:
Second: Have you check your tires presure, balance and how bad is it worn?
Sound like your wheel is out of balance.
Just for future reference you should introduce yourself on your first post to get a warm fuzzy welcome
I might have to have Jethro, Zoom zoom and Randy talk to you :wink:

 

Welcome aboard.

A few more details might be helpful - rather than just pulsing. Hell, when I zap some of my dates with a tazer, they pulse too. You mean more like a vibration? A surge in speed while holding the throttle steady? Does it happen only once you hit certain speeds?

 

Thanks for the welcome. I've been lurking for so long, I never realized that I didn't make an introduction post!
I'll definitely check my tire balance, thanks!

 

It's a pulsing vibration that starts at 120km/h, meaning it vibrates for a second then smooths out for a second and repeats for as long as I'm moving over 120km/h. The vibration increases in intensity as I move faster, but the intervals between vibrations remain the same. It happens regardless of throttle position, it seems to be tied to speed. There are no noises (although I admit it's hard to hear my engine at 120) or otherwise alarming sensations I have been able to associate with the vibration, so I think it's just something come loose in the geometry. I just have to sort out what exactly.

 

:hss: Take you over a year to come out of the rock.......... ound:
Glad to have you mate and good luck fixing the Vibr

 

My first guess would be tires as well. They in good shape? Any noticable flatness to them? The fact that you start to feel it around 120 lends itself to being out of balance, but since you state there are intervals between the vibrations makes me second guess that.

How's the chain an sprockets? Did you put the bike on the center stand recently and check the chain for any tight spots (which are somewhat normal, but maybe you got a really bad one).

Just throwing out some suggestions...

 

I'm with Pliskin on this. Also check your front tire for cupping, but that is usually noticeable on braking. I think every tire I have used on mine has cupped on the front, including 2 PR2's and one PR3. Have never figured out why this happens and I checked the balance and air thing on that too.

Please let us know what you determine to be the problem. Then I can offer it up as a suggestion to someone else and everyone will start to think I am a VFR guru.

 

Tires...FO SHO! I had the same problem after a long trip a while back and when I got new tires, I never felt the vibrations again. You can feel them most in your feet, right? It was like you said, vibration for a second, off for a second, on for a second, like in a wave pattern...harder the vibration the faster I went...

 

as I say that, it could have been balancing, too. It was the first set I had put on after I bought the bike and I had a professional shop do it. The PO may have also, but he was big into the DIY stuff, so he may have had them out of balance. Regardless, new tires and balancing with the install fixed the issue...

 

How many miles on the bike ??? And why do people seldom state their mileage when it can usually help diagnosing problems ?

Check the chain as Pil suggested, cuz loose-then-tight spots or kinked links can cause similar vibrations. If your chain has more than about 25k miles, it needs replacement.