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can we go deeper on Dyna Beads and balancing?

I've been through 3 or 4 sets of the same tires on my current ride and they all wore differently. Go figure.

Check. That is a possibility--it may have been coincidence. (I'm a social scientist so my mind works by assessing plausible causality).
 
My 2 cents

I've been using DynaBeads for 3 sets of tires now. At first I didn't understand the physics of the principle so I read a lot and watched the infamous videos until I got it. It's very counter-intuitive and unless you're good at that sort of thing or curious enough to bang your head against it until you understand, you may not. This is indeed as polarizing as any oil thread, you'll find smart folks on both sides.

Here is some food for thought.

Dynamic spin balancer issue:
MCN made a mistake with this test. There is a fundamental difference between a wheel/tire assembly spinning on a spin balancer, and on a vehicle axle.
The vehicle axle is free to move up and down whereas the spin balancer axle is not.
If you need proof, go to the tire store, grap the balancer axle and try to move it. Now grab your motorcycle FD and try to move that.
In the first instance, be careful with your back, in the second, don't tip the bike over.
The MCN test indicated that the wheel/tire required weights in the same place, beads in or not. The reason was, the beads distributed evenly around the tire perimeter because there was no eccentric axle motion.

When not to use DynaBeads:
a/ Some tire manufacturers say they will void warranty. If you care, don't use them.
b/ Don't put them in your track bike. The violent wheel RPM changes send them flying around the tire and racers don't like them.

How they work:
This is difficult, I've not yet found an "Oh yah" explanation. Here's what works for me:
An 'out of balance' wheel/tire assembly causes the axle to rotate off-center or eccentrically. An off-center excursion forces some beads to collect opposite to its direction. In a few rotations, the beads collect in a distribution that nulls out any off-center excursions.
If you have too few in the tire, there won't be enough balancing mass and the assembly will still shake, although less.
If you put in more than necessary, the excess beads will collect evenly around the tire and not have any effect on balance.
The net result is that the mass distribution will match whatever conventional lead weights are required.
Some people report an improvement in cupping, I don't have anything to add to that. I will say however, the beads will continually shift to match any uneven tire wear, so have that advantage over fixed weights.

Recommendations:
Innovative balancing makes recomendations on the amounts to use. I've followed those with no issues.
I recommend putting them in through the valve stem.
I also recommend removing a tire with little regard to the fact that beads are inside. Once you get the tire half off, you can recover 98% of the beads with a paper scoop, sweep the rest up and throw them out. The old beads will have some 'stuff' in with them which I blow away with light air pressure. Weigh the old beads and top up to the recommended mass.


Lastly:
Have an open mind.
If you really don't think they work then provide reasons why.
Not everything is obvious, who'd have thought that a nut and bolt would stay torqued without glue?
Sometimes, the universe works with us and this one is truly a gimme.
 
If you really don't think they work then provide reasons why.

I tried them in a new unbalanced front tire that had been on the bike for a week -- I got increased vibration between 60-70mph. Took them out and the problem went away. I realize there are many who say the opposite happened. All I have to go on is my own experience with them.
 
"Dynamic spin balancer issue:
MCN made a mistake with this test. There is a fundamental difference between a wheel/tire assembly spinning on a spin balancer, and on a vehicle axle.
The vehicle axle is free to move up and down whereas the spin balancer axle is not.
If you need proof, go to the tire store, grap the balancer axle and try to move it. Now grab your motorcycle FD and try to move that.
In the first instance, be careful with your back, in the second, don't tip the bike over.
The MCN test indicated that the wheel/tire required weights in the same place, beads in or not. The reason was, the beads distributed evenly around the tire perimeter because there was no eccentric axle motion."


OK. But how do the beads know whether that up-down is caused by an imbalance or bumps. If they redistribute due to the up-down so be it but the balance doesn't change every time you hit a crack in the pavement.
 
I tried them in a new unbalanced front tire that had been on the bike for a week -- I got increased vibration between 60-70mph. Took them out and the problem went away. I realize there are many who say the opposite happened. All I have to go on is my own experience with them.

Maybe you were now feeling that over due valve adjustment? :laugh

Just kidding... I do very much agree w/ your assessment.
Go on your own experience. :thumb
 
OK. But how do the beads know whether that up-down is caused by an imbalance or bumps. If they redistribute due to the up-down so be it but the balance doesn't change every time you hit a crack in the pavement.

Good point Paul:

I don't have a good answer for that. For sure, the beads will shift in response to a bump in the road. Perhaps they would make things worse in a washboard situation - don't know. However, I will say, if the road is bumpy, balanced wheel/tire assemblies are likely secondary and one ought to slow down to maintain control.

You've brought up something I haven't seen before.
Keep thinking.
 
I read somewhere on some board a long time ago that they are constantly redistributing.
That being said...
After you come to a stop to avoid a pot hole and slowly roll forward there is no need for tire balance.
At the higher speed/revolutions the beads will redistribute again.

As for cracks in the pavement the beads would need to overcome inertia to redistribute on such a small 'blip'.
 
As for cracks in the pavement the beads would need to overcome inertia to redistribute on such a small 'blip'.

A couple of times when on the road I have omitted balancing a tire and have notices a minor thumping or vibration from the imbalance. But the minor thumping that was detected was slight compared to bumps or even pavement seams as on a concrete Interstate. The movement if any from the imbalance was certainly less than from the pavement cracks.

As I said in my first post, I don't know if the beads work or not, but I am trying to understand how they would work, assuming that they do.
 
As I said in my first post, I don't know if the beads work or not, but I am trying to understand how they would work, assuming that they do.

I'm right with ya on that...

As I understand there are reasons they are the size they are and ceramic as well.
Frost clumping is one.

For my learning curve(s) there are two ways I learn.
Doing and asking questions.
 
Dyna Beads

It's surprising to me that the company that manufactures Dyna Beads hasn't commissioned a non-biased, i.e. university, research study to determine the efficacy of Dyna Beads. I don't know what the going rate might be for such a study, but based on my university experience, I'm betting that a simple study could be had for less than $20K. Just a guess. Every motorcycle forum that I've checked has the same discussion re: Dyna Beads. And it's just like ours, some folks swear by 'em, others swear at 'em!

:lurk
 
I really don't understand what all the discussion is about. They don't fix anything and they make tire balancing harder. What is there to discuss?

When I get tires put on they balance them and I ride, no more balancing till my next set. Whether I ride motocross, do wheelies, or jumps the grand canyon the wheels are always balanced. You can run the argument of "what if you throw a weight?". I carry a few stick on weights in my bag for that very reason. If one flies I stick another in it's place, done. It's never happened to me...ever.

With the beeds your always in a perpetual state of balance and unbalance. Every time you stop your wheels lose balance. Every time you hit a significant bump you lose balance. If you change tires you have to mess with beed swapping. If you let air out of your tire you can get beeds stuck in your stem.
All for what? a tire thats only balanced when your cruising and requires more work:dunno.

These are good for semi trucks and large vehicles that are a pita PITA to balance.
 
but I am trying to understand how they would work, assuming that they do.

In a spinning tire any beads will, due to centripetal force, be spread out around the inner circumference of the tire. Assuming a round tire with no low spots where the beads could accumulate the location of the beads will be somewhat random. Next assume (there's a lot of assumptions going on here :whistle) that the tire and/or wheel is out of balance enough to cause a reaction against the sprung suspension. [If there is no sprung suspension the beads will do nothing.] As the tire goes around the heavy spot will cause the suspension to compress. In an extreme case the out of balance wheel/tire could lift the tire from the road.

So you've got beads plastered against the inner circumference of the tire, the tire connected to the wheel, and the wheel moving up and down with the suspension. As the heavy spot aligns with the forks the wheel tends to hop up. At that instant the beads in contact with the upper circumference will not follow the new path of the wheel, but instead will tend to continue at a tangent. Thus, for a short while, the beads at the top of the tire will not be in contact with the tire. The beads at the bottom will. This temporarily changes the mass of the tire/wheel and, in theory, tends to counteract the out of balance effect on the suspension. I'd guess the effect would follow the sine function with maximum force/change of mass as the heavy spot is in alignment with the forks. That is only a guess.

Or something like that. :laugh

The parts I don't get... what happens during velocity changes? Will an out of balance wheel alway wind up in harmony with the suspension... after how long? What effect, if any, will a deformed tire due to rough road conditions have? What effect will suspension damping have? Etc.

They may work at a constant velocity on a smooth road.
 
this is all very interesting. i find it odd that people get such varying experience with the Beads...
can someone explain the Static Balancing process for me please? is that on a stand with the tire held vertically?
 
Put an axle through the wheel. In the case of the rear wheel on a modern BMW you need an adapter so the axle is centered. Both ends of the axle fit in bearings. Suspend the bearings far enough off the ground so the wheel spins freely. Let the wheel go and the heavy spot will sink to the bottom. Rotate the wheel about 1/4 turn and watch the heavy spot sink to the bottom again.

Here I am checking the wheel sans tire using the Marc Parnes balancer and an older version of his rear wheel adapter. Some tires come with a colored dot which marks the light spot on the tire. You match that with the heavy spot on the wheel which is assumed to be the valve stem. Notice where the valve stem is in this picture.

p-20090724-1441-5466.jpg


On this wheel the valve stem is the light spot. Interesting. But then these days fewer and fewer tires are marked with the dot so the actual location of the wheel heavy spot isn't so important, I guess.

Balance is done by adding weight to the light spot (the top when the wheel stops). When you've got the right amount the wheel will stop in random spots when given a gentle spin. The balancer is good enough in practice that you will not find the PERFECT amount of weight. You'll get it to where adding or removing 5 grams is enough to move the heavy point from one location on the wheel to another. That is plenty close enough.
 
I really don't understand what all the discussion is about. They don't fix anything and they make tire balancing harder. What is there to discuss?

When I get tires put on they balance them and I ride, no more balancing till my next set. Whether I ride motocross, do wheelies, or jumps the grand canyon the wheels are always balanced. You can run the argument of "what if you throw a weight?". I carry a few stick on weights in my bag for that very reason. If one flies I stick another in it's place, done. It's never happened to me...ever.

With the beeds your always in a perpetual state of balance and unbalance. Every time you stop your wheels lose balance. Every time you hit a significant bump you lose balance. If you change tires you have to mess with beed swapping. If you let air out of your tire you can get beeds stuck in your stem.
All for what? a tire thats only balanced when your cruising and requires more work:dunno.

These are good for semi trucks and large vehicles that are a pita PITA to balance.

I'll take a shot at your statement that your "tires stay in balance", sorry to inform you that maybe they suit you the whole time they're on the bike, but they wear unevenly & thus are not in balance with the same weights in place.A tire thats balanced "while I'm crusing is the reason I balance it in the 1st place!? Carrying weights to stick back on-I have a hard enough time remembering where I've been , let alone how much weights on the wheels of various vehicles-get real-do you have a "wheel weight log"? As to being hard to install, beads are very easy and besides you are paying someone else to do it anyway so what's the point there? Yes they work in big truck tires. Going on, as stated there are bead threads that extend to many posts elsewhere and go all over.
While I am not a tree hugger(I cut em down on purpose at times!) nor a Sierra clbbie , etc., I keep mentioning the lead in the environment thing and it never gets any further attention? Subaru quit lead weights some time back and they are illegal in some states(I think?) and definitely hard on Bambi. Google the subject and you will find that lead weights that fall off are a major source of lead in the environment! This also means that they are no longer presnt on some of your wheels-the beads, meanwhile, are snuggly inside doing their thing for my balancing task. No, I don't think the beads "know what they are doing or where they are" but they work for me and save me $ and I control them during and after installation. I will add, that many on Advrider have used plastic BB's to the same advantage. Just pour them in before the tire bead setting operation.
I love bead threads for the "smoke & mirrors aspect they offer" which is hard to come by in an oil thread!
 
But then these days fewer and fewer tires are marked with the dot so the actual location of the wheel heavy spot isn't so important, I guess.

Your wheel is more likely to be out of balance than your tire. I haven't bothered balancing the rear wheel/tire for the last couple of years. No vibration issues. I do balance the front, but could prolly get away without doing it.
 
I'll take a shot at your statement that your "tires stay in balance", sorry to inform you that maybe they suit you the whole time they're on the bike, but they wear unevenly & thus are not in balance with the same weights in place.A tire thats balanced "while I'm crusing is the reason I balance it in the 1st place!? Carrying weights to stick back on-I have a hard enough time remembering where I've been , let alone how much weights on the wheels of various vehicles-get real-do you have a "wheel weight log"? As to being hard to install, beads are very easy and besides you are paying someone else to do it anyway so what's the point there? Yes they work in big truck tires. Going on, as stated there are bead threads that extend to many posts elsewhere and go all over.
While I am not a tree hugger(I cut em down on purpose at times!) nor a Sierra clbbie , etc., I keep mentioning the lead in the environment thing and it never gets any further attention? Subaru quit lead weights some time back and they are illegal in some states(I think?) and definitely hard on Bambi. Google the subject and you will find that lead weights that fall off are a major source of lead in the environment! This also means that they are no longer presnt on some of your wheels-the beads, meanwhile, are snuggly inside doing their thing for my balancing task. No, I don't think the beads "know what they are doing or where they are" but they work for me and save me $ and I control them during and after installation. I will add, that many on Advrider have used plastic BB's to the same advantage. Just pour them in before the tire bead setting operation.
I love bead threads for the "smoke & mirrors aspect they offer" which is hard to come by in an oil thread!

All you have to do is look at the size weight that on there and keep an extra couple. If one gets thrown it's pretty easy to see where it was by the little square ouline with nothing in the middle.

Whether they use lead weights or weights made out of goat cheese they still do the same thing.
 

yeah i saw that video once before, on the Dyna Beads website, after i heard about them from a buddy of mine. it's relatively easy to understand how -and i mean without knowing the actual physics of the matter- centrifugal forces and the dynamics of wheel/tire mass etc., will allow the beads to re-assemble themselves with each start/stop.

for me, here's the thing:
quite obviously, the old way works well- it's a time tested reality. also, it stands to reason that modern tires no longer require as much offset in added weights to achieve balance as they once did. the fact that several folks have stated they got better overall wear out of their tires with the beads is enough for me- i, too, have experienced scalloping or uneven tire wear over the years on different bikes.
not being an engineer or physicist, this very concept FEELS sensible to me. OK, it's NOT our granddaddy's tire balancing method.... but for the most part, we aren't riding our granddaddy's bikes either.


i likes to take advantage of new technologies, and i know many of you guys do, too- tell me you don't have a big fat GPS/Sat NAV or a Blackberry or iPhone? why not employ any and every tool available to us?

i'm goin for it.

i don't ride as much as some of you guys, AND i have 5 bikes, so my year's mileage totals are spread out between at least two of them, or more in any given year, with the bulk of my riding spread out between the two BMWs. why wouldn't i try the beads in one out of 5?

i'll mention to the shop guys i want them to install Dyna Beads in the new tires on the K100. it'll be interesting to see if this sparks comment or debate from them!
 
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