Recently I've been noticing a buzzing vibration at between 4 and 5k rpm on my nina 500, especially the first few gears. It could have been there all along and I just started noticing it (I've only had the bike a couple of weeks and wasn't riding terribly smoothly the first week). Anyone else experience this or have an idea what it is? The bike is an 06 with 4k miles on it. The actual sound of the buzzing doesn't bother me as much as the worry that there is something wrong with my new bike =(
thanks

 

well i think it could be ur windshield, i dont know why, but my bike is doing that as well, same rpm, im just guessing the right amount of vibration is causing it! thats my gues, i have been wondering it myself, when riding, hit that rpm again and when it starts doing that, grab the shield and aply pressur to it so it stops vibrating, and it might eleminate the problem, i have tried to tighten mine and it dont do any good, but i might try again, i dont know, its a misstery! let me know how it goes

 

good chance its ur fairings as well ,,,i read in one of calamarichris' posts he has put some padding in his fairings like the bigger ninjas have to stop some of that ...i notice mine has that sound occasionally as well, as long as its a plastic sound of buzzing is better than a metallic buzzing imo lol

 

Actually, the fairing dampers are strictly to reduce the amount of natural engine noise perceptible to me. It really doesn't do anything to quell any vibration.
In America, the torque curves in motorcycle magazines ALWAYS show the torque and horsepower curves intersecting at 5252 rpm. And there must be something magic about that rpm, because most twins seem to have a buzzy (or in some cases earth-shattering vibration) at that rpm. It's just the nature of the beast with twins. It seems to vary slightly from model to model, but there's something about that transition from lower-rpm torque to higher-rpm horsepower that causes a little buzzing. If there is anything loose, this is probably pretty close to the rpm in which it will let you know it wants tightening.

Is this buzzing mostly a sound, or is it a buzzy feeling in the handlebars/footpegs?

If it's noisy, you probably have a fastener loose or missing somewhere. Could be a fairing screw, a an exhaust header-bolt, or anything. Have you had the initial service done? One of the functions they (should) perform on the initial service is the checking and tightening of all nuts and bolts listed in the general maintenance chapter of the service manual.
I recommend either getting a copy of the service manual (& supplement), a torque-wrench and a tube of low- and medium-strength threadlock and doing it yourself. I did them to my '06, and it's a comforting feeling to cruise down the road with the confidence that every crucial fastener on that bike has been meticulously treated with threadlock and torqued precisely as prescribed by the engineers who designed this bike and selected the alloys for each of itits systems.
And over time, the service manual will pay for itself. It shows you step-by-step like a cookbook, how to perform all the other maitenance tasks on your bike. Not all shops/dealerships are crooked and inept, BUT no matter how much you pay someone, he's still not going to put the love & Q-tips into taking care of your bike that you would.

OR if you simply want to get this out of the way, I recommend borrowing a half-shell helmet that exposes your ears and going for a ride and listening to both sides of the bike at that rpm. I have an old half-shell helmet that I seldom wear, but still consider a good trouble-shooting tool to have in the garage for occasions like this.

I'm in the San Diego area and can help if you're near here. Good luck and let us know how it goes or if any other questions come up.
Peace!
-CCinC
P.S. Here's what the threadlock looks like:

 

The numerical values of horsepower and lbf·ft of torque are always equal at 5252 rpm because 5252 rpm in the numerator cancels out the constant, 5252 in the denominator leaving only the torque figure equal to the power figure.


on a dyno, only torque and speed can be measured; Power must be calculated from the torque and speed figures according to the formula:

Power = Torque X Speed / K

Where K is determined by the units of measure used as can be seen below:
To calculate power in horsepower (hp) use:

HP = Torque X rpm / 5252

where:

Torque is in pound-feet (lbf·ft)
Rotational speed is in revolutions per minute (rpm)
To calculate power in kilowatts use:

kW = Torque X rpm / 9549

where:

Torque is in newton-metres (N·m)
Rotational speed is in revolutions per minute (rpm)

 

I was aware of that, but my post was already getting a little long-winded; there's a time for the theoretical and there's a time for nuts-n-bolts..
Thanks!
-CCinC

 

hell im more confused than when i started :P

 

hahaha, read between the lines iroc. Some good info right there in front of ya.

 

I just want to join the bandwagon. I also hear "something" different about the engine noise in the 4-5k rpm range. I was surprised, and kind of glad, to hear others hear something too. The leprechauns assured me this noise is perfectly natural, but the pixies kept asking me if maybe I might not be right in the head! Obviously the pixies are overreacting.

It really sounds like the engine noise changes, and then changes back in this RPM range. Or maybe there is an adiitional sound on top of what what I consider normal. If this is actually something on the bike (like the fairing) transmitting the engine noise differently to my ears, that's hella deceiving!

I always thought the "sound" test is an excellent test of any mechanical device, and some not so mechanical. Of course, getting directly from "the sound" to "the fix" is often difficult. I need to try this while the bike is not moving and see if I can narrow down the source.

 

The sound test is helpful; but in my dream world, dealerships would include a copy of the bike's service manual with the sale of each bike they sold, and we owners would run through the list of fasteners in the General Maintenance chapter and make sure they're all cleaned, torqued properly, and thread-locked where specified in the manual.
But I understand dealerships are in business to make money and the surest way for that to happen is to have fasteners work themselves loose which causes larger problems, which causes us to pay the dealership to repair.
The more nickels you spend on toothpaste and floss, the fewer dollars you end up paying the dentist.
Peace!
-CCinC