DynaBeads

[_cy_]

my question is... why even fool with dyna beads? it's not like balancing a tire is hard to do. a standard balance using weights uses the smallest amount of weight possible.

[Tim McKittrick]

Well, in my case I didn't have a balancer. Now that I do I favor of the tape weights. My stateside bike has Dynabeads in it's tires because I don't have access to a balancer where the bike is kept.

[Xmoto]

The Dynabeads will keep the tire balanced as it wears and weigh less than conventional weights.

[Yossarian™]

Originally Posted by Tim McKittrick

OK- I'm looking at the above pic again and it strikes me that if I had had the Dynabeads stick in the valve when checking the tire pressure

Seems to me that in your case of beads stuck in the valve, that one burst of air INTO the valve would have cleared it pretty quickly. If not, then manually depressing the valve plunger as much as possible would allow the beads to drop out.

I've been using the beads on a couple of my bikes and have not had any air loss issues.

[sorebutt]

Originally Posted by Tim McKittrick

OK- I'm looking at the above pic again and it strikes me that if I had had the Dynabeads stick in the valve when checking the tire pressure (which is what I had always assumed had been the case) I probably would have noticed all of the air wooshing out before I replaced the cap. The only other plausible explanation I can come up with has to do with track speeds. It's possible for the Schrader to be flung slightly open at really high speeds- which is why one is supposed to use metal valve cover caps with a gasket inside of them when fooling about on the track- or have those cool valves that exit the rim at a 90 degree angle. Perhaps a combination of high speed and perfectly timed bumps along with a synchronous positioning of the Dynabeads is a more accurate explanation for this happening- and may explain why it has occurred to some of us but not to others. How fast have you gone with Dynabeads in your tires? My failure happened at a venue that allowed a top speed of about 120MPH (for my machine- thats about all a thumper can be expected to do) on a really bumpy track.

Even plastic valve covers had a small o-ring. Caps are part of the entire system. They not only help seal against small leaks, but they also keep debis out of the stem that may cause a leak. Air pressure in the tire should force the schrader valve shut. It looks to me that the beads must have damaged the valve and forced their way inside.

I've found many tires today come pretty well balanced. Many don't even have the dot to show where to line up the valve stem. I've found my rim is more out of balace than some tires. However, an out of balance tire would have a greater affect because it is on the outside of the rotating mass. I find that if a tire takes a lot of weight to balance I can rotate the tire on the rim and it will take less weight.

Here is my take on how the beads work. They don't migrate to the lightest place. That is impossible. They simply add mass to the outside of the rotating mass. The increased mass will override any slight difference in tire balance. Those people that say they work have tires that are already close to being in balance and those that say they don't work have used them with a tire or wheel that is a long way from being balanced.

[Yossarian™]

Originally Posted by sorebutt

Here is my take on how the beads work. They don't migrate to the lightest place. That is impossible.

I don't think you have a very good grasp of how dynamic balancing systems work.

No offense intended; it is probably not something that is intuitive.

However, they do work, and are in wide use in a variety of applications. Dynabeads are merely one method of dynamic balancing.

[sorebutt]

Originally Posted by Yossarian™

I don't think you have a very good grasp of how dynamic balancing systems work.

No offense intended; it is probably not something that is intuitive.

However, they do work, and are in wide use in a variety of applications. Dynabeads are merely one method of dynamic balancing.

Perhaps you can enlighten me. Just saying they work doesn't help.

[sTE610vE]

I use them, they have worked exactly as advertised for me. Running rim-locks in both front a rear and they have worked great up to 90+mph.
No problems with air leakage from the valve core. Follow the directions for how much to add and the core and you should have no problems.
I use a metal valve core cap with a rubber gasket which should also stop any air getting by the core, but I have never seen that anyway.
http://www.innovativebalancing.com/motorcycle.htm

Explanation on how they work and more info+
http://www.innovativebalancing.com/HowItWorks.htm

[the kaz]

I just balance my tires when I change them and never worry about anything until I replace them

[baloneyskin daddy]

I've always wondered how well they stay in place under hard braking and acceleration. Insome cases a tire itself will actually move on the rim under extreme circumstances and they're locked in place with a bead. There is nothing keeping any beads or liquids from spinning inside the tire under these circumstances which would cause momentary imbalance at a most inopertune time in my opinion.

[Yossarian™]

Originally Posted by sorebutt

Perhaps you can enlighten me. Just saying they work doesn't help.

In addition to what has been posted so far, here is a Youtube video of another application of dynamic balancing.

http://youtu.be/ullnFQD4F1I

[DiasDePlaya]

I will test with ATF, because I have, because it don't freeze and because it don't rust anything.

I did the same test with a small plastic bottle than DynaBeads youtube video and worked 100%.

[_cy_]

Originally Posted by Xmoto

The Dynabeads will keep the tire balanced as it wears and weigh less than conventional weights.

say it takes 1.5oz of lead weight to balance a tire.... please explain how it takes less dyna bead weight to achieve same?

let's assume for sake of argument that dyna bead is not snake oil and it works as advertised.

conventional balancing is easy and has zero issues. besides clever marketing, why in the world would anyone need dyna beads?

convinced dyna beads are a solution looking for a problem. sorry there's no problems with conventional balancing.

a balancing rig can be made for dirt cheap. two roller bearings, one solid shaft and some spacers. resting on two jackstands. heck a harbor freight balance stand is about $37.

[max384]

Originally Posted by _cy_

say it takes 1.5oz of lead weight to balance a tire.... please explain how it takes less dyna bead weight to achieve same?

let's assume for sake of argument that dyna bead is not snake oil and it works as advertised.

conventional balancing is easy and has zero issues. besides clever marketing, why in the world would anyone need dyna beads?

convinced dyna beads are a solution looking for a problem. sorry there's no problems with conventional balancing.

a balancing rig can be made for dirt cheap. two roller bearings, one solid shaft and some spacers. resting on two jackstands. heck a harbor freight balance stand is about $37.

I'll play devil's advocate here. Two problems I can think of right off the bat with conventional balancing are weights falling off and the tire wear over time can change the light spot on a tire. I used to work as a mechanic and would see both of these problems come in quite often. Granted, I worked as a car mechanic, not a bike mechanic, but I would hazard a guess that these problems exist on bikes as well. Dyna Beads would solve both of these problems (if they work as advertised, of course).

[jules083]

Originally Posted by max384

I've been using Dyna Beads for about the last 30,000 miles. I've been sold ever since. I've had a glass smooth ride every time...

However, a curious thing happened a couple weeks ago. I got a nail in my rear tire. The tires were nearly shot anyhow, so I decided to change both front and rear. I was in a hurry because I was running late due to the unexpected tire changes. In my rush, I forgot to put Dyna Beads in the front tire. Guess what? Glass smooth ride. It's been over 2,000 miles since forgetting to put the beads in... and it's still a glass smooth ride. Now, I have kept the original wheel weights in place in both of my bikes that I've used the Dyna Beads in.

I'm beginning to wonder if I've been using snake oil all along...

I think from now on I'm not going to balance the tires or use the Dyna Beads. If it's a smooth ride, great! If it's not, I'll try adding Dyna Beads. If that smooths out the ride, than I'll be reasonably certain that Dyna Beads work. If it fails to work, I'll be reasonably certain that Dyna Beads are snake oil.

I did the same thing when I changed my FJR rear out a few months ago. Didn't have any beads, so I just mounted it and hoped for the best. I can't tell the difference.

I do plan on buying a balancing stand one day though, and have this hair-brained idea to start running Craigslist ads to make a couple of bucks mounting tires for people.