Dynabeads - Anyone use them?

[duc_fan]

Anyone use these?

http://www.innovativebalancing.com/

http://www.innovativebalancing.com/motorcycle.htm

http://www.compacc.com/p/Dyna-Bead-Bike-Packs/1714002

There's a ton of discussion over on ADVRider, with believers and naysayers duking it out.  An engineer by trade, I am half tempted to create a Verification & Validation matrix, write a test plan, and put these things through their paces.  Wish I had the time.  In the meantime, I'm just curious as to whether any of the local Ducati-ridin' ruffians have used these.

Ride safe!  [moto]

[DucHead]

I use them in the tires of my airplane which takes off from the conveyor belt in my back yard.

[pennyrobber]

Anyone use these?

http://www.innovativebalancing.com/

http://www.innovativebalancing.com/motorcycle.htm

http://www.compacc.com/p/Dyna-Bead-Bike-Packs/1714002

There's a ton of discussion over on ADVRider, with believers and naysayers duking it out.  An engineer by trade, I am half tempted to create a Verification & Validation matrix, write a test plan, and put these things through their paces.  Wish I had the time.  In the meantime, I'm just curious as to whether any of the local Ducati-ridin' ruffians have used these.

Ride safe!  [moto]

I would like to see some independent verification. I for now remain hugely skeptical.

[mitt]

I am skeptical that most riders under 75mph even benefit from traditional wheel balancing.  Modern mc rims and tires are pretty damn good to start with.  I haven't changed my stock weights on my Monster since owning it, and going through 4 sets of tires.  I have a simple balancer, but haven't used it since the first tire change.


mitt

[duc_fan]

I use them in the tires of my airplane which takes off from the conveyor belt in my back yard.

 

Best response I've read on any forum, hands down.

[Bones]

my ex-girlfriend used to use thunder beads and she swore by them.......ohhhhhh DYNABEADS....nope never heard of them.

[Christian]

I'm no engineer or physics major, but won't these pile up in one spot as the wheel builds up centrifugal force?

[scott_araujo]

I'm no engineer or physics major, but won't these pile up in one spot as the wheel builds up centrifugal force?

My thoughts exactly.  A friend of mine who used to race motocross used to put ATF in his tires to 'self-balance' them.  I think both the ATF and these beads would pass the baisc wheel balance test: spin the wheel and it stops in a different spot.  Balanced, right?  I think it's just doing that because the friction of something moving inside the wheel makes it stop in different places.  I have no proof but I think these things are just crap.

And is it so unbelivably hard or expensive to get tires balanced the usual way?  Don't people do it successfully every day?

Scott

[pennyrobber]

Lets say you have a tire that is perfectly balanced an a wheel that is way out of balance. Instead of slapping weight on the wheel you use these things instead. At a stop, these beads would all be piled at the bottom of the tire and the wheel and tire would likely not be in balance. As you speed up, the beads begin to get distributed throughout the tire and ultimate centripetal acceleration holds them against the tire carcass. Now the only way I could see that the majority of the beads would go to the side of the tire that needs extra weight would be if somehow, the unbalanced wheel oscillation shook the beads to the required spot. The problem is, the largest rotational moment is going to be focused at the point were the wheel is heavier and logic would tell me that the beads would want to find their way there making the balance even worse. Think of one of those old style party noise makers that you spin around on the handle. If you fill that thing with beads, they aren't going to move to the opposite side of the spinner and balance the whole thing out.

[duc_fan]

I'm no engineer or physics major, but won't these pile up in one spot as the wheel builds up centrifugal force?

I don't use them, I'm just curious if anyone on here has used them.  That said... the rationale is that the beads will evenly distribute themselves when in motion, and if there is an imbalance, they will redistribute themselves just enough to balance it out.  The excess beads will be evenly distributed.

My thoughts exactly.  A friend of mine who used to race motocross used to put ATF in his tires to 'self-balance' them.  I think both the ATF and these beads would pass the basic wheel balance test: spin the wheel and it stops in a different spot.  Balanced, right?  I think it's just doing that because the friction of something moving inside the wheel makes it stop in different places.

What you refer to is static balance, and no liquid or bead-type dynamic balancing agent is applicable in that case.  They only "work" when the wheel is spinning.

Did your friend ever experience wheel vibe from a lack of balance?  One thing to bear in mind is that one real-world test is worth more than a thousand guesses/opinions.

Again... I don't have these, haven't ordered them, not sure I ever will.  But I'm curious.  In an open-minded fashion, I am simply wondering if anyone on here has first-hand experience with them.  My curiosity is making me seriously contemplate testing these things.  Add them to a previously balanced wheel/tire.  Remove the weights and test again.  Try them with a new tire and no weights.  Try with and without the beads with the weight in a wrong spot (i.e. test with and without them in a known-unbalanced wheel).

[duc_fan]

Lets say you have a tire that is perfectly balanced an a wheel that is way out of balance. Instead of slapping weight on the wheel you use these things instead. At a stop, these beads would all be piled at the bottom of the tire and the wheel and tire would likely not be in balance. As you speed up, the beads begin to get distributed throughout the tire and ultimate centripetal acceleration holds them against the tire carcass. Now the only way I could see that the majority of the beads would go to the side of the tire that needs extra weight would be if somehow, the unbalanced wheel oscillation shook the beads to the required spot. The problem is, the largest rotational moment is going to be focused at the point were the wheel is heavier and logic would tell me that the beads would want to find their way there making the balance even worse. Think of one of those old style party noise makers that you spin around on the handle. If you fill that thing with beads, they aren't going to move to the opposite side of the spinner and balance the whole thing out.

I wondered the same thing until I saw this:

How Centramatic Balancers Work

For an object that is free to move, remember that will want to rotate around the center of mass.  That means in an unbalanced wheel, the CM is not at the axle... it is closer to the heavy spot.  This means as the wheel vibrates, the point furthest from the center of rotation is not the heavy spot... it's the light spot.  The beads move there until the vibration is reduced and the spinning wheel comes back into balance.

[He Man]

I'm no engineer or physics major, but won't these pile up in one spot as the wheel builds up centrifugal force?

unless u had instant force from a hard take off i think they would roll around before being pinned to the wall. another thing to note is that there are little grooves on the inside the tire, and im sure one of these can sit almost 1/4 up the wheel without falling. so do they do anything really?

I will say one thing, i dont have weights on my tire. My wheel is NOT balanced. ive ran them for over 12,000 miles that way. and ive hit 130mph from time to time, and had it maxxed out on a dyno. the bike doenst jutter like its about to fall apart or whatever.

Im not saying you shouldnt do it, im just trying to give a real example of mitts point, you could get away without ever doing it and not notice it because most tires are off by so little.

[Christian]

That video is awesome. I love science. So it looks like these would actually work. Although I wonder about low speeds - it seems like without the magnet, the wheel in the video shuddered more with the balancer on it until it got up to speed than without the balancer.

Still - very interesting stuff!

[Christian]

Also, not to split hairs, but:

As you speed up, the beads begin to get distributed throughout the tire and ultimate centripetal acceleration holds them against the tire carcass.

I think we're talking about centrifugal force here. Centrifugal force moves away from the center - out from the wheel into the tire.

[He Man]

well if you want to split hairs, centrifugal force isnt  really a force.