Dyna Beads-do they work

[gator]

Work for me

I have been using them for 4 yrs. Last tire I got I had done on the road while it did not feel bad it cupped badly. I do not get cupping on my R110RS (yes I ride fast) if I use dyna beads I do if I have it spin ballanced.
Gator in Dallas

 

[OfficerImpersonator]

Theoretical physics

A wheel/tire combination balanced using traditional weights will always be "in balance".

A wheel/tire combination balanced using small balls inside the tire itself won't always be "in balance".

When the tire strikes a pothole/curb/etc., those balls/beads will be temporarily displaced out of position, and during the time between impact and up until the balls/beads reassemble themselves into "balance", the tire will be out of balance.

The same is true for starting from a dead-stop. The video above demonstrates this phenomena. Until the beads/balls migrate into a balanced position as the wheel comes up to speed, the wheel is out of balance.

So - for some portion of the time that the wheel is in motion, a tire balanced using beads/balls will be out of balance, imposing stresses on the equipment a traditionally balanced wheel will never experience.

In my mind, the question now becomes: Is the aggregate of the of time when the wheel is out of balance while the beads/balls align themselves from start-up or after an impact with an irregularity in the road surface enough so that over time, these additional stresses and strains shorten the life of components (tires, wheels, axles, bearings, suspensions, etc.)? Even if it's only a fraction of a second in each instance, over the life of the components, those fractions add up to minutes and then hours of exposure to forces for which the component might not be designed.

I'm mostly just thinking out loud here. My degree is in the social sciences, so I have no expertise in applied physics. Actual physicists are encouraged to check my math.

 

[MotorradMike]

A wheel/tire combination balanced using traditional weights will always be "in balance".
Actually, it will be pretty good when it leaves the shop but will change a bit with wear. Small point, not going to argue.

A wheel/tire combination balanced using small balls inside the tire itself won't always be "in balance".
When the tire strikes a pothole/curb/etc., those balls/beads will be temporarily displaced out of position, and during the time between impact and up until the balls/beads reassemble themselves into "balance", the tire will be out of balance.
The same is true for starting from a dead-stop. The video above demonstrates this phenomena. Until the beads/balls migrate into a balanced position as the wheel comes up to speed, the wheel is out of balance.
Agreed.

So - for some portion of the time that the wheel is in motion, a tire balanced using beads/balls will be out of balance, imposing stresses on the equipment a traditionally balanced wheel will never experience.


In my mind, the question now becomes: Is the aggregate of the of time when the wheel is out of balance while the beads/balls align themselves from start-up or after an impact with an irregularity in the road surface enough so that over time, these additional stresses and strains shorten the life of components (tires, wheels, axles, bearings, suspensions, etc.)? Even if it's only a fraction of a second in each instance, over the life of the components, those fractions add up to minutes and then hours of exposure to forces for which the component might not be designed.
I have never felt the beads positioning themselves. Guys on the track do because they change speeds so quickly. Don't use DynaBeads on the track. My belief is that a well balanced set of tires(almost all the time) far outweighs any unbalanced set-up time. It's only 2 ounces plus original imbalance = 4 ounces worst case. for about 100 revolutions.

I'm mostly just thinking out loud here. My degree is in the social sciences, so I have no expertise in applied physics. Actual physicists are encouraged to check my math.

But Officer, you see how they work right?
Do I have a convert? Just for the principle, not about warranty or wear or the points you've made.
Just the principle.

It's not something for nothing, it's just using the physics to advantage.

 

[OfficerImpersonator]

But Officer, you see how they work right?
Do I have a convert? Just for the principle, not about warranty or wear or the points you've made.
Just the principle.

It's not something for nothing, it's just using the physics to advantage.

Seeing how they work in theory on a riding lawn mower tire in a laboratory is easy.

Seeing how they work in real life riding conditions on a real life motorcycle encountering real life roads would be far more useful.

 

[E_Page]

When going slowly, like when I'm navigating the speed bumps on our private road or going up my driveway, it does not make much difference whether the tire is balanced or not. Without speed, there is not enough force acting upon any of the parts associated with the wheel to cause any damage or feel any imbalance.

It's only when you gain speed that these forces become significant. Think about a laundry wash machine with an unbalanced load. As the spin cycle starts, you won't notice anything amiss. As the tub spins faster, the machine starts banging and rocking. Same thing with the tire/wheel assembly.

With the beads, as I gain speed, they apparently settle into their proper place. It must not take much to do so, because I never feel anything amiss. My speed changes are generally not so quick as to cause any problems with the beads. I guess if I were regularly hitting bumps and dips that bounced them out of place, it would render them ineffective. But if I were regularly hitting bumps and dips at speed enough to knock the beads out of place on my RT, I'd have other worries than whether my wheels were staying in balance.

 

[lsouth3]

Someone must have said
"Try to avoid telling someone what they are doing does not work while it is working".

 

[kantuckid]

Based on the above, explain why my tires don't show the result(uneven wear from beads) of the many!!! "Topes" & terrible roads I've ridden with my present set of tires? Perhaps it doesn't matter that they get "shaken around" & in practice are quickly redistributed? They work.