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If I planned on riding 120 MPH+, I would have a shop balance my tires/wheels, but riding mostly 55 to 70 MPH I haven't had any problems.
 

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I don't think so. Do you remember the balance machines that would spin a tire/wheel while mounted on a car? I had one where the normal speed at the time of 55mph a balance was just fine. But when I got a lead foot and open road it would shake the heck of me at 120mph. So in the previous example of balancing high for a motor, does it too have a spot lower where things are not well balanced or is the above example I have just specific to that style of balance machine?
It could have been inadequate balance, or maybe tire construction. Tires flex and rebound, and this process can set up a vibration due to resonance in the carcass. Good tires are designed to absorb most of this, and are usually stable up to their rated maximum speed. Another reason racing tires are different.
 

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Foist to the point WS raises. I will not buy Dunlop 404 tyres again after the balance problem I had with the front tyre on Yami. I always balanced my own wheels for the bikes I used at the track, and never had a problem.

Back to the OP
The first pic at left, shows a bolt of a smaller diameter, thru the bearings. Note the weight clamped to the disc, about 6 inches away from TDC, while the wheel remains in a stationary position. Other pic. Same wheel, same weight. This time in a balancing stand. Any movement of the weight from TDC, will cause the wheel to turn. Half an inch from TDC is enough to cause the wheel to turn.
My conclusion: is that there is more resistance to turn, or stiction friction, using the narrower bolt method.
Turning the wheel by hand shows the bearing sliding on top of the bolt. The bearing does not turn. Grease on the bolt would help the wheel turn, and a bit of wiggle would likely cause it to move. However the pliers represent a fair chunk of weight. For finer adjustments I would suggest the bolt method has its flaws. Your test may reveal different results, but frankly I would not bother.
I should add. I am holding the wheel in place in the second pic. I had trouble getting it to stay in place. UK
 

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I think we need to chat with a Ducati MotoGP mechanic, and ask him or her, how they balance their wheels. I am positive it will not be using a shaft, smaller than the hole in the bearings. Another issue with higher speeds is the tire losing shape, or coming apart. Barry Sheen at Daytona, had the tire expand and rub on the frame, and blow at around 180.
For MotoGP, Michelin does a static balance. you can see them working in the background of this video.
 
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Sweet, thank you for that. The long axel shaft will be the same size as the bearings. The stand I think has two bearings each side, that the axel sits between them, where they form a rounded convex V. So the axel turns with the wheel, and turns in the cradle of the two bearings. The wheel bearings are not turning. This is partly from what I see on the video, and partly from memory of yesteryear. What we wanted was the axel shaft to turn more freely, so we could be more precise. Simon is a Kiwi. Once upon a time, I knew many of the top NZ riders, even though I was about 10. Peter Murphy and Rod Coleman are searchable. UK
 

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Discussion Starter #26
Rod diameter doesn't matter, because
1. wheel always turns around inner bearing race, not around rod of any diameter. (rope can be used instead of rod.)
2.Location of inner race will be always in lowest possible position (top of inner race on rod)
 

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I use this rig to balance my tires, the cones center the wheel bearings on the shaft, and the shaft sits on 4 very low friction ball bearings. It's very sensitive, I've balanced about a dozen wheels, some of them have been run pretty fast and all of them run smoothly.

The weak spot of this device is the aluminum shaft, it's straight now but I'm sure it could be easily bent through rough handling, I treat it with kid gloves.
 

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The weak spot of this device is the aluminum shaft, it's straight now but I'm sure it could be easily bent through rough handling, I treat it with kid gloves.
Isn't there a machine shop where you work with a lathe that you could turn a nice steel rod to replace that one?
 

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Discussion Starter #29
shaft sits on 4 very low friction ball bearings.
this is important info from you: 4 bearings, each of them has friction.
Video in post 1 clames "no friction"
No doubt your balancing machine can be upgraded to perfect if a vibrator from adult toy store is attached to it.:)
 

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Rod diameter doesn't matter, because
1. wheel always turns around inner bearing race, not around rod of any diameter. (rope can be used instead of rod.)
2.Location of inner race will be always in lowest possible position (top of inner race on rod)
So I wasted my time doing an experiment, where I observed the inner race not turning.
Four low friction bearings, with a long axel between two of them each side, can turn much more freely than the two wheel bearings in the wheel. Wheel bearings grease versus sewing machine oil is one reason why.
The guys in the video, post number 24, are balancing wheels for bikes going over 200 mph, with the worlds best road race riders. I am surprised we all have it wrong.

My balancing machine, has bearings that turn more freely than the bearings in the wheel, and more freely than the smaller diameter rod. The pics back up my conclusion.

We figured out how to balance wheels a very long time ago. These days most riders do not know how to change a tyre.
You can give me a virtual pat on the back, for teaching many how to do it, back in the seventies. UK
 

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Krusty, you can lead a horse to water, but can you make him drink?
 
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Discussion Starter #33
My balancing machine, has bearings that turn more freely than the bearings in the wheel
You are absolutely right!
Except it seems you missed one most important thing: moving vise grips back and force in the video eliminate friction completely. Bearing grease in moving condition becomes kind of liquid. At least this is idea. I didn't see in description of your experiment how you did that. Did I miss it? Should I read it again?
You said it: "bit of wiggle would likely cause it to move " That is it!!!
PS Different opinions are normal, especially on bike forums... :):)
 

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In the pics I posted. With vice grips 6 inches from top dead center, the wheel did not turn. I was not holding it.
In the other pic, I had to hold the wheel to stop it from turning.
With the narrow axel, I observed the wheel bearing climbing up and over the axel. A bit of wiggle likely would have got the wheel to turn in the narrow axel test. However, it was not required when in the balancing tool.
This should indicate, that the narrow axel had more resistance, than the balancing tool, and therefor an inferior method.
Others, please do your own tests. That is the way it is done in science. I have posted my findings. It is now for others to prove, or disprove my conclusions. But there is more. If the narrow axel is a superior system, why are the guys who work for the tyre companies, or a MotoGP team, not using the narrow axel system. I would suggest because they no better.
Lastly: Have you ever balanced your own wheels, and run them at a track, at 145 mph, and 95 mph, every two minutes for half an hour. I have. I have know problem with a difference of opinion. Happens to me all the time. Rookies are often correcting me on my riding style and other issues.
I do not know your age. However I would like one thing for your future. Ride often, and walk straight when you are seventy. UK
 

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Rod diameter doesn't matter, because
Because in the video from post #24 they are using a narrow 'axle' but.... You can see the tech slip a collar of some sort over the narrow axle that centers the assembly. (You can see that in the first 4 minuets). I'm thinking there could be low friction bearings in that collar and /or on the stand the narrow axle rests on.

MotoGP team, not using the narrow axel system. I would suggest because they no better.
Yeah but those machines will only run what, 200+ MPH...

The good news is that at the max speed most street riders will ever see perfect wheel balance is not an absolute requirement. Even though "good enough never is" in this case good enough might be okay for the narrow axle guys. Wouldn't be good enough for my riding style but it's widely known that I am crazy, so there is that.

S F
 

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Isn't there a machine shop where you work with a lathe that you could turn a nice steel rod to replace that one?
Oh yeah, I have some backup plans if I mess it up, we have plenty of toys at work to make things with.
I used to have a very nice lathe of my own , it’s still in my ex wife’s basement along with some other shop tools that were deemed part of the house :-(


Sent from my iPhone using Tapatalk
 

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I did not miss it. You might notice I referred to him as Mr Wiggle. That was a clue. If he has to wiggle the narrow axel, as you suggest I do, then there is too much friction. I have suggested if you want to have a contrary opinion, you do your own test. Is that too much to ask? Show me. I still have lots to learn. I am not that young to know everything. You are skirting around many of the points I have raised. Like the MotoGP guys using a different method or my past experience. Is there a reason for this? Open you mind to other possibilities. You are stuck in a rut. It can be done. Bon chance. UK
 

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I just realized,
We are all using a bunch of unnecessary words and videos to answer this simple question...
Is it a good way to balance tires?
Answer , No!

S F
 
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Well there ya go UK, you got another one to play with. This time not political so you might be able to play a long time.
 
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