High Speed vibration

[mynewbusa]

hey guys, I just wanted to see if anyone has had this happen to their bike at higher speeds. I've had the bike since May. I haven't had a good chance to really open it up the way I'd like to, and see what it has. On a few occasions I'd get a high speed blast in.  A few months ago I was riding in the north counrty of New York. Very desolate road, but nice and smooth, newly paved. I jammed down a few gears and let her rip. I was at about 148 or so sitting fairly prone, not tucked under the screen. I started to get a vibration, it wasn't in the steering so much as it felt like it was a heavy buzzing, or vibrator. Sorry to use that description, but!!! Well any way, I backed off and figured it was because I was sitting up and maybe because my jacket wasn't zipped up all the way  I was creating some kind of turbulence. I haven't had much chance to ride lately, so I kinda forgot about it. This past weekend I went to New Hampshire for a Nascar race. I rode with a friend of mine and we had a great day. The ride is alot of 2 and 3 lane highways, nice roads, ets.. so any way, we're headed home and we're getting pretty close to home. We are on a two lane divided highway without a car in sight for miles, so I decide I'm going to put the hammer down. I go down a few gears and then roll on the gas. I get to about 145 or so and I feel the vibration again. Its pretty pronounced, so it bothers me. I tuck under the windshield to see if it makes a difference. Still I could feel the vibration. It feels like something in the front end is being buffeted hard from the wind. (no doubt) I don't think I noticed it with any of my other bikes. I only have 2300 miles on this one, tires pressures were exactly where they should be. I don't normally ride at that speed, but occasionally it can happen, just wondering if anyone has had a similar feeling, is it normal because of the shape of the fairing or something. I though the aerodynamics of the fairing were supposed to very good. It may have nothing to do with the fairing though. I doubt it's something I'm going to worry about for long, any suggestions/coments??

 

[MC MUSTANG]

Most people start noticing a buzz about 4.5k on the tach... mine doesn't go away as I go through speed...

What does your bike feel like in that area? It might be a buzz/vibrations that starts, but isn't pronounced enough to discern until you get her up in the higher numbers...

 

[QUICK]

same here above 4.5 on the tach. Not bad thou, just have to stretch the feet out once in awhile on long rides.

 

[Devious]

(QUICK @ Sep. 19 2006,12:07) same here above 4.5 on the tach. Not bad thou, just have to stretch the feet out once in awhile on long rides.

Welcome to the Board...
Always glad to see a 1st timer here...

 

[Gunnybusa]

Buzz is from the engine but the vibration could be from an unbalanced wheel or low tire PSI.

 

[MC MUSTANG]

(Gunnybusa @ Sep. 19 2006,12:10) Buzz is from the engine but the vibration could be from an unbalanced wheel or low tire PSI.

UNbalanced wheel is what I am thinking...

 

[MO-BUSA]

maybe you threw a wheel weight?

 

[mynewbusa]

(Gunnybusa @ Sep. 19 2006,13:10) Buzz is from the engine but the vibration could be from an unbalanced wheel or low tire PSI.

I don't know, I'm familiar with the buzz at 4.5k rpm, this is much different. I don't feel anything at any speed up to that point, so I think an unbalanced wheel would not be it. I can ride at 120 mph all day and never feel it, but if I go 145 or more I feel it. To describe it as best I can, I'd say -if you had a flag blowing in the wind at 145mph it would be blowing straight back and tightly vibrating, not waving in the wind. that might not be a great description but its kind of like what I've seen from maybe a flag on your truck antenna at speed. I really dont feel it in the steering or suspension, more like the body itself. I don't get an occilation in the handle bars like an unbalanced wheel or low tire pressue. I obviously can't go out and rip up the streets to try to narrow it down without getting arrested, I guess unless I plan on riding that fast that often I shouldn't worry about it. Maybe the air is catching a body panel somewhere and causing the heavy buzz, I don't know. I'd like to say it doesn't bother me, but I know I'll sit here and stew about it!

 

[Gunnybusa]

(mynewbusa @ Sep. 19 2006,13:24)

(Gunnybusa @ Sep. 19 2006,13:10) Buzz is from the engine but the vibration could be from an unbalanced wheel or low tire PSI.

I don't know, I'm familiar with the buzz at 4.5k rpm, this is much different. I don't feel anything at any speed up to that point, so I think an unbalanced wheel would not be it. I can ride at 120 mph all day and never feel it, but if I go 145 or more I feel it. To describe it as best I can, I'd say -if you had a flag blowing in the wind at 145mph it would be blowing straight back and tightly vibrating, not waving in the wind. that might not be a great description but its kind of like what I've seen from maybe a flag on your truck antenna at speed. I really dont feel it in the steering or suspension, more like the body itself. I don't get an occilation in the handle bars like an unbalanced wheel or low tire pressue. I obviously can't go out and rip up the streets to try to narrow it down without getting arrested, I guess unless I plan on riding that fast that often I shouldn't worry about it. Maybe the air is catching a body panel somewhere and causing the heavy buzz, I don't know. I'd like to say it doesn't bother me, but I know I'll sit here and stew about it!

So what do you think it is? I had a killer vib that would start after 115, it went away after I put new tires on.

 

[PaNDeM1C]

Maybe it's your nerves rattling at 148? LOL!

j/k

 

[CorrodedAlien]

check all the fairing fastners, if you do not "feel it" in the bars or your seat, it may just be a missing or loose fastner.

 

[GSXcite]

(CorrodedAlien @ Sep. 19 2006,15:43) check all the fairing fastners, if you do not "feel it" in the bars or your seat, it may just be a missing or loose fastner.

+1 also, are you running a stock or aftermarket windshield? May be getting some vibration there, as some aftermarket windshields are not as thick as the OEM one.

 

[Quasar]

Without being able to hear/feel for ourselves, it can be kind of hard to pinpoint however, by the time you reach 145 MPH, it would be of vital importance to make certain ALL screws holding your plastics in place (including your front fender, side plastics and windscreen) are tight and none are missing. Plastics could easily become a flapping vibration at those speeds.

Otherwise, wheel balance is a possibility as it only gets worse with speed even though you say you feel nothing at 120 MPH. Resonance occurs are certain speeds, so wheel balance or out-of-round tires could still be your issue.

Check all your screws in your plastics first from top to underneath.

 

[PaNDeM1C]

Could be a helmet strap, keys, anything... at that speed there's a LOT of noise. Like others said, try to be specific.

 

[mynewbusa]

(PaNDeM1C @ Sep. 19 2006,17:12) Maybe it's your nerves rattling at 148? LOL!

j/k

LOL!!! Balls of steel, nerves of Knievel!!! But thanks to all who responded. I know its a hard thing to diagnose over the computer. I'm a service director for an auto dealer, so I know that you have to drag all the info out of a customer when a noise/vibration comes up. You all brought up some good starting points. I'll be checking all the fairing fasteners, fender, etc.. The windshield is stock, but I've had it off before, I'll double check that. Still not sure about the tires being a problem though. I guess anything is possible. Maybe I'll have the shop check balance before I put it up for the winter. Thanks again guys