Dyna beads fail with pics

[fonque]

I know this topic has been beaten to death, but i got rid of the dyna beads in both my tires. They did not work. I would get a vibration that would oscillate from front to rear and back at any speed above 85mph. 

After unseating the tire, i found that the beads were stuck in place and covered in black stickyness. They were not freely rolling at all. I had to jostle them pretty hard to get them to free up and drop to the bottom of the tire.

 

My theory is the tire compound is too soft for the beads to work properly, combined with the inner tire ridges impeding the beads from rolling freely.

I have another bike with bias-ply metzlers on and they are balanced with beads without issue.

 

Let me know what you think.

[V-FORE]

Very interesting, what tire's are they? I have not had any problems with them in my experience, but if I do I will have some ideas thanks for posting!

 

 

Gary

 

[fonque]

I have Metzler roadtec Z8's on my 5th gen.

[PirateRiderBen]

I don't even balance my tires anymore. Third set now with no balancing and they wear and ride perfect just fine. (2 sets of PP3's and a set of M7RR's im

on now)

[Rice]

Used them once when they just came out.  Didn't work for me - Still had vibrations.  Never used them again.

In my case, the beads have remained loose.

 

P.S.

Never meat a tire that didn't need to be balanced.

[Duc2V4]

37 minutes ago, Rice said:

 

P.S.

Never meat a tire that didn't need to be balanced.

Since buying my tire changer and wheel,balancer I found some tires so out of balance that it takes the wheel a long time to stop penduluming back and forth, so much so that I often have to break the bead again and rotate the tire in the rim. Even then it takes a few oz. of weight to get the tire to keep from swinging on the balancer! I'd hate to see how that tire would feel at speed.

[Mohawk]

OK I'll bite, how can a bunch of loose beads of what (lead I assume) balance a tyre in motion ?  

 

The physics says that depending on the rate of acceleration & thus wheel rotation, they will be pinned in place by centrifical force almost immediately. Even if that was not the case, there is no way they can work out where the lite side of a tyre is on the rim ! never mind staying there. They would be dislodged by accerlation, bump & braking forces periodically & then pinned in place by centrifical force as soon as possile there after, so pointless IMO.

 

To the poster that does NOT balance their tyres, you miss the second point of balancing. The first is to stop major out of balance vibrations etc, the second is to protect your wheel bearing from minor out of balance vibrations that you don't feel, but will help to prematurely wear your bearings out.

 

Likewise Duc2V4, changing the postion of a tyre on a rim should have NO effect on the balance. If it does then your primary assembly is also out of balance ! You should balance the wheel without a tyre if this is the case, then the only thing you will be compensating for will be tyre density & layup imbalance, rather than the primary assembly.  I call it that as rarely is a wheel just a wheel, it often have brake discs or parts of a cush drive or chain wheel attached !

 

 

[Rice]

9 minutes ago, Mohawk said:

OK I'll bite, how can a bunch of loose beads of what (lead I assume) balance a tyre in motion ?  

 

The physics says that depending on the rate of acceleration & thus wheel rotation, they will be pinned in place by centrifical force almost immediately. Even if that was not the case, there is no way they can work out where the lite side of a tyre is on the rim ! never mind staying there. They would be dislodged by accerlation, bump & braking forces periodically & then pinned in place by centrifical force as soon as possile there after, so pointless IMO.

 

To the poster that does NOT balance their tyres, you miss the second point of balancing. The first is to stop major out of balance vibrations etc, the second is to protect your wheel bearing from minor out of balance vibrations that you don't feel, but will help to prematurely wear your bearings out.

 

Likewise Duc2V4, changing the postion of a tyre on a rim should have NO effect on the balance. If it does then your primary assembly is also out of balance ! You should balance the wheel without a tyre if this is the case, then the only thing you will be compensating for will be tyre density & layup imbalance, rather than the primary assembly.  I call it that as rarely is a wheel just a wheel, it often have brake discs or parts of a cush drive or chain wheel attached !

 

 

There have been extensive discussions of the virtues of dynabeads about...  7-8 years ago when they appeared on the horizon.

I then took the time to read the "scientific" justification for why they are supposed to work and it never made sense to me.  Still, being humble enough to accept that the fact that I don't understand something doesn't mean that it isn't true, and also because the price of admission was low enough, I bought'em.  Still have a vial of them sitting around on the shelf - Should anyone want them, they are yours for the cost of shipping.

 

And Mohawk, I don't think I understand your point re. no effect on balance of changing position of the tire relative to the rim. 

[Duc2V4]

As much as I agree that balancing the wheel (sans tire), twice I had to re-position the tire to keep the tire from penduluming the wheel when put on the balancer. Maybe because they were take off tires and possibly worn differently but my observations was by rotating the tire on the rim, it helped with the balancing. At least not having to add a ton of additional wheel weights on the wheel.

 

From what I hear/read from others and from tire manufacturers there is no light or heavy spot indicator on tires and that they are pretty much as "balanced" as they can be right from the factory, so balancing the wheel should be all that is required so maybe on the next tire change I'll try that again and see what happens. 

[BCmcrider]

I don't use the dynabeads but I do understand the theory.  

 

What everyone seems to not understand is that a freely suspended rotating mass (think about a wheel/tire assembly in outer space not mounted on forks) will rotate about the center of mass, not about the center of the bearing hole.  What that means is that the lightest part of the assembly will be swinging around further from the center of rotation than the heavier part.  Think about a sledge hammer rotating in space, the tip of the handle would be a lot further from the center of rotation than the head.  This means that from the point of view of each individual bead, it's a downhill path toward the lightest part of the rotating assembly vs the heavier part.  Each time the bead gets slightly disturbed by the road deforming the tire slightly, it has another chance to move downhill, toward the lightest part of the rotating assembly.

 

When the tire/wheel/bead assembly is mounted on a motorcycle and turning at speed, the suspension and tire deformation allow it enough freedom to rotate about it's center of mass.

 

That being said, I balance my own wheel/tire assembly with stick on weights using cold rolled steel shaft, two washed bearings, and two jack stands, and achieved a balance that was better than the crappy job the shops always did.

[vfr350]

i'm gonna throw this out there, i could see the inside grooves being an issue, but the inside rubber is tacky as well. on my mountain bike to keep the tubes from sticking to the inside of the tires i coat the inside of the tires with baby powder, tubes never stick now. could this help the beads from sticking?

[rhoderage]

I think VFR350 hit it; if your tire is wet on the inside then the dynabeads are going to stick to the moisture and fail to do their job.  Whether you add baby powder or just dry the inner of the tire really well, I suspect that is key to having these perform as described

[FJ12Ryder]

It all sounds great, but is gravity acting on those beads going to be enough to offset the amount of centrifugal (or centripetal if you're really anal) force acting on the beads to hold them in place against the pull of gravity? It's not like the beads are free to move around, just like those people on the whirly-things when the floor drops away. Gravity doesn't pull them down because they are held in place by the spinning action of the wheel.

 

However I do check all the wheels I have changed tires on, for balance with no tire. My experience is that most tires don't really seem to need much weight added. Usually the wheel is light at the valve stem area, I guess due to the amount of wheel material removed to mount the valve stem. I usually see how much weight it takes to balance a naked wheel and then I know how much off the tire is. And most aren't very much off.

[Mohawk]

On 23/05/2016 at 2:10 PM, Rice said:

And Mohawk, I don't think I understand your point re. no effect on balance of changing position of the tire relative to the rim. 

 

Ok, so if the wheel assembly is properly balanced, then it will stop randomly on the balancer due to bearing friction, so perfect balance.  If we now add a tyre to this known perfectly balanced wheel assembly & its out of balance, then the only change is the addition of the tyre. So if we say for convenience that when the heavy part is at the bottom, and the valve is at 3 o'clock. Now if we take the tyre off & move it around the rim exactly 180degrees, then the valve should now be at 9 o'clock when the heavy part is at the bottom again !

 

As far as tyres being balanced, have you ever seen a "How it's Made" program on tyres ? The core is made from belts of different materials, the tyre skin is made from various rubber compounds, then the tread is LAID up on the skin in strips, so dual compound will have the soft layup on the sides & the hard layup in the center.  These are just strips of rubber, that have to over lap at the ends, image a tape measure around your waste, to cut it exactly & glue the ends together is very difficult, so cut it a little long & glue the overlap together. This is effectively what they do on a tyre, to avoid a real heavy spot they stagger the overlaps, but its all done by hand, thenthe tyre aseembly is put in a mould that blows it out to fill the mould & heat welds or vulcanises the material into a homoginus single piece that bonds to the belts. Thus creating the threaded tyre we get to fit, but that tyre has both mass density verables & the overlap areas which whilst squashed in the mould, still work out denser than the rest of the tyre, so heavy spots !

 

 

[SCguy]

If you do want to use beads, don't spend the money for Dynabeads. Pick up Airsoft BBs anywhere.

[Rice]

2 hours ago, Mohawk said:

 

Ok, so if the wheel assembly is properly balanced, then it will stop randomly on the balancer due to bearing friction, so perfect balance.  If we now add a tyre to this known perfectly balanced wheel assembly & its out of balance, then the only change is the addition of the tyre. So if we say for convenience that when the heavy part is at the bottom, and the valve is at 3 o'clock. Now if we take the tyre off & move it around the rim exactly 180degrees, then the valve should now be at 9 o'clock when the heavy part is at the bottom again !

 

As far as tyres being balanced, have you ever seen a "How it's Made" program on tyres ? The core is made from belts of different materials, the tyre skin is made from various rubber compounds, then the tread is LAID up on the skin in strips, so dual compound will have the soft layup on the sides & the hard layup in the center.  These are just strips of rubber, that have to over lap at the ends, image a tape measure around your waste, to cut it exactly & glue the ends together is very difficult, so cut it a little long & glue the overlap together. This is effectively what they do on a tyre, to avoid a real heavy spot they stagger the overlaps, but its all done by hand, thenthe tyre aseembly is put in a mould that blows it out to fill the mould & heat welds or vulcanises the material into a homoginus single piece that bonds to the belts. Thus creating the threaded tyre we get to fit, but that tyre has both mass density verables & the overlap areas which whilst squashed in the mould, still work out denser than the rest of the tyre, so heavy spots !

 

 

Thanks for the detailed explanation.

Do you think that there is value in balancing the bare wheel alone and then again with the tire? 

[zupatun]

yes.   I balance the wheel alone...and I mark that spot somewhere on the rim with a dot of orange or red paint...I always know the true heavy spot on my rim.  I never have to re-find it.  Now some tires have the heavy spot marked and I put that dot 180deg from the dot on my rim  when I change tires...

 

BTW has anyone ever been to a AMA race and watched the Dunflop guys or the Pirelli guys (when it wasn't a spec tire race) change tires on rims?  It takes them literally about 15 seconds to find the heavy spot and balance the tire...at most 30 seconds...they just get good at finding and estimating where and how much.  Truly cool to watch how fast a human can find it with practice.  When I do it once a year it takes me maybe 2-3 minutes to get the weight right...but I balance within 1/8 oz...or half a little square of lead.  I use a pair of dykes to cut them apart...and I use duct tape (black) to cover them so balance the tire with them just stuck to a piece of duct tape and then take the backing off the sticky part once I find the heavy spot and the right amount of weight...tape has some weight to it.

 

Matt

[vfr350]

 

On 05/24/2016 at 2:56 AM, rhoderage said:

I think VFR350 hit it; if your tire is wet on the inside then the dynabeads are going to stick to the moisture and fail to do their job.  Whether you add baby powder or just dry the inner of the tire really well, I suspect that is key to having these perform as described

 

rhoderage, the more i thought of this, even if the tire is dry dont they normally slather on soapy water around the bead to seat? thats kinda what looks like spilled in on the picture here, not sure anything works for that.

[zupatun]

For bikes, No-mar makes a paste rather than the liquid lubes.  On a car tire, they can probably get away with some runny stuff on a sponge.  I use something like this, but not the no-mar brand.

 

http://www.nomartirechanger.com/Tire_Lube_Paste_1_Pint_Jar_p/sp-lube-paste.htm

 

[FJ12Ryder]

20 hours ago, zupatun said:

yes.   I balance the wheel alone...and I mark that spot somewhere on the rim with a dot of orange or red paint...I always know the true heavy spot on my rim.  I never have to re-find it.  Now some tires have the heavy spot marked and I put that dot 180deg from the dot on my rim  when I change tires...

 

BTW has anyone ever been to a AMA race and watched the Dunflop guys or the Pirelli guys (when it wasn't a spec tire race) change tires on rims?  It takes them literally about 15 seconds to find the heavy spot and balance the tire...at most 30 seconds...they just get good at finding and estimating where and how much.  Truly cool to watch how fast a human can find it with practice.  When I do it once a year it takes me maybe 2-3 minutes to get the weight right...but I balance within 1/8 oz...or half a little square of lead.  I use a pair of dykes to cut them apart...and I use duct tape (black) to cover them so balance the tire with them just stuck to a piece of duct tape and then take the backing off the sticky part once I find the heavy spot and the right amount of weight...tape has some weight to it.

 

Matt

Where do you find lead wheel weights? They quit making them years ago. I've been trying to find some and am forced to reuse old ones when I can find them. Or do you make your own?

[wera803]

2 hours ago, FJ12Ryder said:

Where do you find lead wheel weights? They quit making them years ago. I've been trying to find some and am forced to reuse old ones when I can find them. Or do you make your own?

I bought some of these. I can't find anything that says they are lead, but they are small like the lead ones always have been. Some rims I balance are too small for the larger steel weights that you can buy now, so use these on those smaller lipped wheels and the steel ones on others.

http://www.amazon.com/Perfect-Equipment-100360-Pre-Taped-Weight/dp/B000CP0KHG?ie=UTF8&psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00

 

I probably do 75-100 tires a year.

 

[wera803]

3 hours ago, zupatun said:

For bikes, No-mar makes a paste rather than the liquid lubes.  On a car tire, they can probably get away with some runny stuff on a sponge.  I use something like this, but not the no-mar brand.

 

http://www.nomartirechanger.com/Tire_Lube_Paste_1_Pint_Jar_p/sp-lube-paste.htm

 

 

Another option for tire paste. This is where I get mine......use a paste brush too, which makes it clean and easy.

http://www.gregsmithequipment.com/11-LB-Xtra-Seal-Euro-Paste-Eco-Wax-White

[FJ12Ryder]

Many thanks Wera803, for the link. After searching around, it does appear that those are stick-on lead weights, not steel or zinc. I also found a seller on Ebay with lead weights, but he's a bit pricey.

 

Again, thanks for the link. I don't do anywhere near that many tires, but I hate the steel weights. They're too big and you have to add too many, even if you're only adding a small amount of weight.

[zupatun]

4 hours ago, wera803 said:

 

Another option for tire paste. This is where I get mine......use a paste brush too, which makes it clean and easy.

http://www.gregsmithequipment.com/11-LB-Xtra-Seal-Euro-Paste-Eco-Wax-White

 

 

Same wheel weights I use and I have a big tub of the Euro paste as well (seemed like the cost of the paste from NoMar drove me to the Euro)...looks like great minds think alike!  ;)

 

Matt

[FJ12Ryder]

I need to get some of that tire lube too, I'm almost out of the No Mar stuff and it is a bit pricey. That stuff looks to work a champ.