HELP High speed shaking...

[ej2006busa]

Well I havent posted much to this forum because she has been running pretty well... except for a shaking that I cant get rid of!
I guess I'll start with the problem. The bike has 30k miles Ive had it for 20k. Below 100 the bike runs smooth with no problems. But as soon as you start to cruise over 100 she starts to shake, like an out of round tire or something similar. It's not as bad if your hard on the throttle, it gets worse as you start to cruise. It's not anything that feels dangerous, it just feels like its going to wear other things out, like suspension etc.
Now for what I've done to her...keep in mind this has been an ongoing problem mostly since I bought the bike. It has had a few times where she runs smooth, but very rarely. I've replaced the tires (both) several times. Replaced stem bearing, and had front forks serviced. New cush dampers, and chain, which I've adjusted several times towards high and low ranges of the spec. New rear rotor. I've checked the rims the best I can to make sure they're not bent or damaged. I went from dyna beads to weights, which the 1st time I did it seem to help but the weights slung off so I rebalanced them and it didnt help this time. My rear sprocket look pretty good both are stock but they dont seem to have any wear on them... at least the rear I cant see the front one. The new chain may have helped a little bit but she's still not like she should be. I'm sure Ive done some other things I just can't think of anything else at the moment. Anyways any help would be appreciated I can't take getting passed by cars on the highway anymore!!

 

[dadofthree]

Wow, even though it's not exact;y hard to do, you have exceeded my knowledge with the fixes you have completed. Tire pressure correct

Just joking

 

[Blanca BusaLess]

Have both wheels properly high speed balanced.

 

[Rocketmn]

That's what I was thinkin'..........

 

[sixpack577]

Have both wheels properly high speed balanced.

This^
You said that balancing with weights helped the first time, then they got slung off.
You can get weights that clamp to the center of the wheel, or the stick-on kind, either is fine.
If you have unbalanced tires, triple digit speeds is where vibration really starts to show.
I would definitely try having both wheels balanced again, regardless of past experience, as anything can be done wrong.
From what you describe, balancing them properly with weight will correct the problem.
You may hear the argument that people street ride without weights or any balancing with no problems all the time.
It does happen...but not often, and I have balanced many tires over the years.
Rarely you'll get a bike tire that balances perfectly and needs no weight. Otherwise, they all need something.
If you ride an unbalanced tire(s), you'll get exactly what you describe, and as said it'll show up as you get close or pass 100mph.
That just seems to be the magic number for most out of balance bike tires. I've ridden and corrected quite a few that were this way.
A static balancer also does just as good a job as a computer balancing machine.

 

[ej2006busa]

Yeah I've also exceeded my knowledge on the subject to apparently!
Well currently my tires are static balanced because the dealership down here doesn't seem to do high-speed balancing I'm guessing about 30 miles an hour plus I don't know when the last time they had their machine calibrated so I figured static balancing might be a better option. But at this point I would be willing to take them off and go have them rechecked. Does a high-speed balancer literally spin the tire faster than highway speeds?

 

[brpo]

I'm curious - when riding at around 60 and 40 mph - if you remove your hands does it have any wobble?

Oh yea - I'm a +1 on dynamically balancing the tire. Static balance isn't as accurate.

 

[sixpack577]

Yeah I've also exceeded my knowledge on the subject to apparently!
Well currently my tires are static balanced because the dealership down here doesn't seem to do high-speed balancing I'm guessing about 30 miles an hour plus I don't know when the last time they had their machine calibrated so I figured static balancing might be a better option. But at this point I would be willing to take them off and go have them rechecked. Does a high-speed balancer literally spin the tire faster than highway speeds?

I don't know the exact speed of a machine balancer.
I do know that of the many static balanced bike tires I've done on many bikes that we've never had a problem.
All the way to top speed too. Just the same as the machine balanced I've done and had done.
It doesn't have to need a lot of weight to cause a vibration either.

 

[Blanca BusaLess]

Yeah I've also exceeded my knowledge on the subject to apparently!
Well currently my tires are static balanced because the dealership down here doesn't seem to do high-speed balancing I'm guessing about 30 miles an hour plus I don't know when the last time they had their machine calibrated so I figured static balancing might be a better option. But at this point I would be willing to take them off and go have them rechecked. Does a high-speed balancer literally spin the tire faster than highway speeds?

There are machines used for car tires which do spin them really fast. But for bikes no not really. Most places will static balance them which is just slowly spinning it by hand and placing a weight where it settles. But to get them spun on a proper balancing machine which will tell the tech exactly where and how much weight to place will at least assure you they are balanced. If the problem still exists than you can start looking elsewhere.
You said you have dynabeads in. I have read many reviews on these that say they are fine up till 100 or so and then same thing happens. I don't think they can handle speed?

 

[ej2006busa]

Thanks for the reply guys.
You can take your hands off of the handlebars at pretty much any speed below 90 and it tracks straight, smooth, and no wobble. I've only got one dealership close by but Ill try and call a few other ones are little bit farther away to see if anybody high-speed balances It would be worth the drive if that might fix it.

 

[sixpack577]

Did you get all the Dyna Beads out before balancing with weights?

 

[ej2006busa]

Yeah I'm going to call around tomorrow to find out if anybody can high-speed balance the tires. I used to have Dyna beads in them and I took them out because the people from dyna bead told me that if there was any other problem with the bike like bearings etc. that Dyna beads well actually Make the problem worse by causing the tires to go out of balance

 

[ej2006busa]

Yeah when I Static balanced the tires we broke The bead and sucked out all the beads that were in it

 

[Blanca BusaLess]

Just find someone who can confidently balance them so we can eliminate that from the list of possibilities.
The fact the previous ones flew off tells me the one who did it before didn't know what he was doing.
Did he stick em one the side of the wheel or what? To simply stick em inside on center will all but guarantee they will stay due to centrifugal force.

 

[ej2006busa]

Well I have had two different people balance the tires the weights that flew off might have been partially my fault because I told him to stick them in the center of the rim for cosmetic reasons but in the center of the rim the weight can't be glued flat against the rim only about half of the sticky stuff was holding it on. So when the other guy static balanced then this time we went ahead and put them almost in the center of the rim on the flat part of it. Now they seem to be staying

 

[RYC1966]

Cheap insurance is some black duct tape over the weights if you can stomach the eye sore....most the time you would have to look hard to find the layer of tape.

 

[ej2006busa]

True that's a good idea

 

[1busa]

Are you sure its the wheels and not the damper? My busa used to get a little loose on me @ high speeds and an Ohlins steering damper got rid of that instantly

 

[ej2006busa]

I'm not sure about the damper I've checked it visually and there's no oil around the ends but other than that I really don't know how to tell if it's working correctly. Although I have been wanting an aftermarket one As soon as I get some more money lol.

 

[ej2006busa]

Hey the busa is fixed! It did end up being the wheels being out of balance. I found a place in Miami that was able to high-speed balance them and I finally got to take it for a test drive a couple days ago and she's smooth at all speeds! Just wanted to thank you guys for the info. The rear tire took 3 1/4 ounces of weight but other than that everything balanced out. And the guy says that there's a good chance that after I replaced that tire may not need that much again some tires apparently just do.