Topic: Ever heard of dynabeads?

[BVCB650]

I didn't. Put on fresh rubber, beads and rode it. Either the tire was perfect right out of the mold, (yea right) or the beads made it perfect.

[mlinder]

I just did a little more research, as I was considering taking an out of balance tire to a tire balancing shop and doing a test with a before and after to show if it does, indeed, balance tires.

However, this has been preempted by dynabeads claim that they would not work with a static balancer.

Why?
Markcb750, you are a physicist (or something), explain this to me. How can the dynabeads defy the laws of physics while attached to a vehicle, yet not defy this same laws when attached to a balancing machine?

Since Dynabeads effects (or lack thereof) is apparently immeasurable unless in tires attached to a moving bike, I guess what has to happen is a sensor that measures...... what, lessee, travel of the fork, and applied longitudinal force to the forks at the axle. and run the exact same road at the exact same speed and compare data...
Yeah, dun think I'm gonna be able to swing that one.

[Markcb750]

I understand why the manufacturer of Dynabeads would not want you to check tire balance on a static balance machine.  The beads would most likely add to the static imbalance. (Although random placement might cause static balance to improve with the Dynabeads in a static balance measurement.)


If the Dynabeads work, , a dynamic balance machine such as the kind used on a car wheel assembly should show balance improvement in response to the magic of the tiny beads.  (all sarcasm intended)

I am an Engineer, Mechanical, machine design specialty. It is my opinion that all Engineers are physicists, except Software Engineers they live "outside" mere relativity constraints. 


 

[BVCB650]

Dyna Beads are tiny, high density ceramic spheres that roll freely around the inside of the tire. As the tire spins these beads roll to a position exactly opposite the tire's heavy points, thereby eliminating any out-of-balance motion. (**scroll to the bottom of the page for a testimonial)

The result is a smoother ride AND a better look - Dyna Beads eliminate the need for ugly lead crimped-on spoke or stick-on wheel weights on your rims. Unlike messy liquid balancing medias, Dyna Beads don't thicken or harden over time. When you need to repair a tire puncture they don't interfere with plugs or patches.
DynaBeads can be used in tubed or tubeless tires, and they also work for scooters, ATVs, or automobiles, and other tires. Contact us by phone if you have non-motorcycle application.
Dyna Beads dynamically balance tires on the move, resulting in a smooth ride that lasts the life of your tire. In fact, your tire will remain perfectly balanced until replaced. By contrast, a tire balanced "the old fashioned way" with lead weights can become unbalanced in as little as a thousand miles. You'll know when that happens because the handlebars start to buzz, and if you look at the front tire (while it's spinning on the road) you'll see it vibrating. That's because the wheel is no longer in balance. As rubber wears, the wheel gradually becomes unbalanced.
So how do Dyna Beads work? Imagine this scenario - you have a washing machine going thru the spin cycle with 3 pairs of blue jeans. As long as there's water in the drum, the machine spins in a perfectly balanced fashion, but as soon as the water drains out, the machine starts that old thump-thump-thumping noise because the load is unbalanced. Pour back some water (or in the case of a motorcycle tire add some Dyna Beads) and the load re-balances itself.
A more technical explanation goes something like this: The tire/wheel/ axle assembly is constantly spinning in an elliptical motion due to the inperfections inherent in tire and wheel manufacturing. If the wheel was perfectly balanced there would be no vibration at the axle, but because no tire or rim is perfectly balanced, you must add lead weights to smooth out the spin. An unbalanced tire bounces up and down because the suspension is storing and releasing energy each time the tire spins thru a rotation. It's a complicated ballet between the various components, with the heaviest point of the wheel pulling the axle off-center. Add balancing media (Dyna Beads) to the inside of the tire and the laws of physics will distribute the beads to a point opposite the heavy point of the tire/wheel asssembly, and the tire will return to a neutral (balanced) spinning point. The tire stops bouncing and any vibration goes away. Whew, enough technospeak!
For the adventuresome riders who change their own tires, and for those who travel to the far corners of the world and have to change their tires in the field, Dyna Beads provide a perfect solution to "field balancing" tires when there's no other method of balancing available. You won't have to rely on the "old red dot at the valve stem" method of tire balancing, hoping that the light spot of the tire will offset the heavy point of the rim (it seldom does).
So how many Dyna Beads do you need in your motorcycle tire?
Smaller bikes require 1 ounce in both the front and rear tires... order DB-2
Medium-to-large bikes require 1 ounce in the front and 2 ounces in the rear... order DB-3
Large bikes (Gold Wings etc) require 2 ounces in front and rear... Order DB-4
When in doubt, order the "next size up". Additional DynaBeads inside the tire won't hurt anything, they'll just help keep the tire balanced and they'll automatically redistribute within the tire, based on the natural unbalance of your tire. By contrast, not having enough Dyna Beads can result in an unbalanced tire because there won't be enough of them to offset the wheel imbalance.

[Mdub]

How can the dynabeads defy the laws of physics while attached to a vehicle, yet not defy this same laws when attached to a balancing machine?

Not a physicist, but the only difference would be the compression of the tire under load.
The compression of the tire as it rolls, creates a high pressure area in front of the compression/road contact point inside the tire. This squeezes the air round and round. Maybe this air movement coupled with road vibration allows the beads to "find their way", rather than just being stuck in one place by the centripidal force?
Just speculatin' ...

[mlinder]

.....the beads would most likely add to the static imbalance. (Although random placement might cause static balance to improve with the Dynabeads in a static balance measurement.)


If the Dynabeads work, , a dynamic balance machine such as the kind used on a car wheel assembly should show balance improvement in response to the magic of the tiny beads.  (all sarcasm intended)...


 

I see. Dynamic meaning there is something that disrupts the static state of the beads increasing imbalance by statically rushing for the most remote section of the tire from the axis, because centrifugal force. This had been an issue that bothered me. Far as my small peabrain can surmise, though, is that the dynamic interruption of centrifugal force is merely that, interruptions, and the beads are still racing towards the point where centrifugal force leads them, after every interruption. That's in addition to my other inane equation listed earlier, though.

[Markcb750]

The air motion inside a tire during rotation would not have any significant pressure front as the tire rotated, the air pressure reaches a static reading as the tire is inflated or loaded, and very quickly the molecules accelerate to the angular velocity of the rotating tire.


The cyclical deflection of the tire  would be a distribution force of the beads, but not toward the imbalance or wobble correction point of the tire.
 


The Dynabead advertising provides no insight as to how the beads magically move to the distribution required for correcting out of balance.  I do not know of any force, friction or fluid flow which would move the beads to the appropriate point in the tire to smooth rotation.


 

[1974CB750rider]

The easiest way to solve this is for all skeptics to take-em about $7.00-$10.00 and buy some and try them. If they don't serve your purpose then don't use them anymore. Its very interesting though that everyone on here who has tried them seem to like them. By trying them you would be able to say hey these work great or no I didn't tell any difference. I enjoy riding my bike and the dyna beads make it ride smoother and I don't have the ugly ass wheel weights on it anymore. I don't know really why they work or how they work exactly but I do know they seem to doing what they're supposed to do. Thats good enough for me to trust them in all my vehicles.

[Markcb750]

.....the beads would most likely add to the static imbalance. (Although random placement might cause static balance to improve with the Dynabeads in a static balance measurement.)


If the Dynabeads work, , a dynamic balance machine such as the kind used on a car wheel assembly should show balance improvement in response to the magic of the tiny beads.  (all sarcasm intended)...


 

I see. Dynamic meaning there is something that disrupts the static state of the beads increasing imbalance by statically rushing for the most remote section of the tire from the axis, because centrifugal force. This had been an issue that bothered me. Far as my small peabrain can surmise, though, is that the dynamic interruption of centrifugal force is merely that, interruptions, and the beads are still racing towards the point where centrifugal force leads them, after every interruption. That's in addition to my other inane equation listed earlier, though.

Dynamic in this case just means the tire is rotating when the imbalance is measured, as modern computer controlled tire balancing machines do. I did not mean to imply dynamic to the movement of the beads in response to it rotating.

Static is measuring imbalance when the tire is stationary on a balance beam as we did when I was a car mechanic in High School.

As far as the effect of centripetal acceleration on the beads, I am saying the same thing you are.  

[mlinder]

BVC, the washing machine analogy does not work for dynabeads, The reason the full washing machine appears balanced is because the percentage of imbalance is orders of magnitude less than an unfilled washing machine.

If the 'basket' of the washing machine weighs, say, 10 pounds, and it is a half pound heavier on one side (5.5 on one side, 4.5 on the other), it's 10% off balance. That's a fair bit
Add 20 gallons of water to it, and now the total (basket and water) now have a combined weight of 80 pounds. The imbalance has dropped to  2.5%.
Of course it's going to 'smooth out', though it's still not 'perfectly balanced.'

This comparison has just about nothing to do with dynabeads.

[mlinder]

.....the beads would most likely add to the static imbalance. (Although random placement might cause static balance to improve with the Dynabeads in a static balance measurement.)


If the Dynabeads work, , a dynamic balance machine such as the kind used on a car wheel assembly should show balance improvement in response to the magic of the tiny beads.  (all sarcasm intended)...


 

I see. Dynamic meaning there is something that disrupts the static state of the beads increasing imbalance by statically rushing for the most remote section of the tire from the axis, because centrifugal force. This had been an issue that bothered me. Far as my small peabrain can surmise, though, is that the dynamic interruption of centrifugal force is merely that, interruptions, and the beads are still racing towards the point where centrifugal force leads them, after every interruption. That's in addition to my other inane equation listed earlier, though.

Dynamic in this case just means the tire is rotating when the imbalance is measured, as modern computer controlled tire balancing machines do. I did not mean to imply dynamic to the movement of the beads in response to it rotating.

Static is measuring imbalance when the tire is stationary on a balance beam as we did when I was a car mechanic in High School.

As far as the effect of centripetal acceleration on the beads, I am saying the same thing you are.  

Yeah. I think by 'static', dynabeads company means "anything you can test scientifically with'. As in, you can't.

[1974CB750rider]

The way they work is the company that makes them is ran by Jedi Knights and they use the Force.

[Markcb750]

the first pic is a static tire balance

The second is a dynamic tire balance, Wikipedia has a one page description of the balance process.

[mlinder]

Oh, so logically, I should be able to take this to a regular tire balancer and check this. Far as I can tell, dynabeads company is calling a dynamic balancer a static balancer, too, though. It's static cause, you know, it doesn't move 'round the shop, it stays in the same place.

[Markcb750]

Oh, so logically, I should be able to take this to a regular tire balancer and check this. Far as I can tell, dynabeads company is calling a dynamic balancer a static balancer, too, though. It's static cause, you know, it doesn't move 'round the shop, it stays in the same place.

As we have been saying, they are selling something that depends on placebo effect, not science.

[BVCB650]

The air motion inside a tire during rotation would not have any significant pressure front as the tire rotated, the air pressure reaches a static reading as the tire is inflated or loaded, and very quickly the molecules accelerate to the angular velocity of the rotating tire.


The cyclical deflection of the tire  would be a distribution force of the beads, but not toward the imbalance or wobble correction point of the tire.
 


The Dynabead advertising provides no insight as to how the beads magically move to the distribution required for correcting out of balance.  I do not know of any force, friction or fluid flow which would move the beads to the appropriate point in the tire to smooth rotation.


 

Centrifical.

[mlinder]

The air motion inside a tire during rotation would not have any significant pressure front as the tire rotated, the air pressure reaches a static reading as the tire is inflated or loaded, and very quickly the molecules accelerate to the angular velocity of the rotating tire.


The cyclical deflection of the tire  would be a distribution force of the beads, but not toward the imbalance or wobble correction point of the tire.
 


The Dynabead advertising provides no insight as to how the beads magically move to the distribution required for correcting out of balance.  I do not know of any force, friction or fluid flow which would move the beads to the appropriate point in the tire to smooth rotation.


 

Centrifical.

There's no such thing as centrifical, BVC.

There's centrifugal, and centripetal.

If you are refering to centrifugal, that force would cause the beads to gather at a point furthest from the axis. That 'lobe' would exist because the tire is already out of balance with that point being the the spot that is causing the imbalance in the first place, therefore increasing the imbalance, which is exactly the opposite of which the bead makers claim their dynabeads do.

[Markcb750]

The air motion inside a tire during rotation would not have any significant pressure front as the tire rotated, the air pressure reaches a static reading as the tire is inflated or loaded, and very quickly the molecules accelerate to the angular velocity of the rotating tire.


The cyclical deflection of the tire  would be a distribution force of the beads, but not toward the imbalance or wobble correction point of the tire.
 


The Dynabead advertising provides no insight as to how the beads magically move to the distribution required for correcting out of balance.  I do not know of any force, friction or fluid flow which would move the beads to the appropriate point in the tire to smooth rotation.


 

Centrifical.

I assume you are forwarding the case that centrifugal force (actually not a real force but a common description of the reaction force required to make a mass rotate about a center) moves the beads to the balance point.  

Won't work:

If wobble is due to an out of round condition the beads will flow to the furthest point from the center of rotation, the very point that is causing the wobble.

If the wobble is due to a concentration of mass (a heavy section of the tire) this point will move further from the center of rotation during rotation and again the beads would migrate there due to "centrifugal" action and again exacerbating the problem.


It's snake oil,and the human placebo effect. The beads spread out like water in a pail slung around your head, doing essentially nothing.

[Markcb750]

I'm off to watch Leno, its up to you now mlinder.   

[1974CB750rider]

mlinder, why won't you just put them in your bike tubes and try them? What is the big deal on how they work or don't work? If you tried them I bet you'd like the way the felt. Take the bike out and ride 50miles with your wheel weights on, come back and mark the spot on the rim where the weights are. Pull the weights off and unscrew the valve stem core, put the dyna beads in, if its a CB750 I would put 2oz in the rear and 1oz in the front. Then go ride the bike another 50miles and then decide which feels better.

[Retro Rocket]

Its very interesting though that everyone on here who has tried them seem to like them.

Placebo effect, How did you actually know that the tyres were out of balance in the first place? A small imbalance would be only detectable at very high speeds and the other way would be to put your wheel on a balancer so unless there was a massive imbalance { the beads would have no effect on this because the rim is out of wack or the tyre is screwed },it would just about be undetectable hence the placebo effect. We have a few laymen here and an engineer, i'll go with the engineer. Oh and also at that price why would the mainstream still manually balance tyres, if these beads were the sh1t then our new vehicles would all have them from the factory. Smoke and mirrors anyone?

Mick

[1974CB750rider]

Again, so far everyone on here who has tried them, has liked them. The only people on here who speak negative about them are the people who haven't tried them. You people who are trying to figure out the science of the dyna beads humor me. Can you really make a scientific deduction about anything unless you try it for yourself? I'm know engineer nor am I a genius. A friend of mine just told me about these dyna beads and said he really liked the way his bike felt. When I put tires on mine I figured I'd try them. I bought new tubes as well even though thier really was nothing wrong with my old ones. I figured if the beads didn't work I could put my old tubes back in and go get my wheels balanced. My old tubes are still in the floor board of my pick up. I say don't knock'em till you try'em.

[Retro Rocket]

Can you really make a scientific deduction about anything unless you try it for yourself?

Absolutely you can, science has boundaries and parameters that don't change and if they do they have been well documented, so what your engineer friend is saying is proven science. If someone told me that if i jumped off a building and flapped my arms i would fly,  i wouldn't have to do the jump to prove anything as i already know the outcome. If you get piece of mind by having them by all means do. Just remember, if these things worked as they say they do there would be a million and one uses for these things and every man and his dog would have them. There has been 100+ years of mechanical development in the automotive world and all the breakthroughs that work find their way into our vehicles at some point, these haven't, thats got to tell you something..

Mick

[mlinder]

Again, so far everyone on here who has tried them, has liked them. The only people on here who speak negative about them are the people who haven't tried them.

That's because the math doesn't add up.

You people who are trying to figure out the science of the dyna beads humor me. Can you really make a scientific deduction about anything unless you try it for yourself?

I'm glad we can supply some humor for someone
Again, though I'm not going to waste the time or money on something that makes no sense. As much as I, and others, have tried to find reason this could work, all I can find is reasons they don't. To make matters worse, the makers can supply no data that proves it works, not theory as to why, and the pseudo-scientific reasons they give are so far off base as to almost appear willfully misleading. As much as I like to think of myself as a really smart, intuitive, objective guy, fact is, this tore up ol body and mind cannot take accurate measurements of minute inputs. The argument of trying them myself to make a 'scientific deduction' just doesn't work. Just think, it could be that there is absolutely no change, but since I already think they are bull#$%*, I might feel like they actually cause more imbalance.

I'm know engineer nor am I a genius.

Neither am I. Well, ok, I'll admit to 'genius' part.

A friend of mine just told me about these dyna beads and said he really liked the way his bike felt. When I put tires on mine I figured I'd try them. I bought new tubes as well even though thier really was nothing wrong with my old ones. I figured if the beads didn't work I could put my old tubes back in and go get my wheels balanced. My old tubes are still in the floor board of my pick up. I say don't knock'em till you try'em.

Right, but you also put on new tires, and didn't ride the bike with new tires BEFORE you put in dyna beads, and if I remember correctly, you were riding on 4 thousand year old rubber with boulders and bronze-age siege weapons stuck in the nearly gone treads.
You don't have a control group in this, because you changed the entire apparatus, not just one element of it.
It's cool, I know you guys like em. I'm not saying you shouldn't use em. But when I smell bull#$%*, I say bull#$%*, until someone SHOWS me it's a pile of roses.
With that said, I WILL take an out of balance wheel to a wheel place and have it checked with and without the beads, and see what we get.

[Retro Rocket]

Neither am I. Well, ok, I'll admit to 'genius' part.

 


mick