PR2 Front End Wobble with dynabeads balancing

[str8]

Did the Dyna-bead thing too.I found them acceptable up to 70 MPH or so. At speeds higher than that I would get a vibration, and at triple digit speeds the beads caused a vibration that was unbearable. (New PR2's)

After removing the beads and doing a conventional static balance, the tires are smooth as glass at any speed.

 

[Auburn]

Ya know, there is somethign to be said about they tried and true method of static balancing and stick on weights. They have been using them on the race track for years to speeds well over 200 mph. Just saying...

 

[Big-D]

Without reading all of the posts prior to posting my two cents worth, I too was using the Dyna Beads. My advise to you is take them out and shit-can them. I ruined a perfectly good set of PRII's using the beads. They caused the tires, both front & rear to get so far out of round, they would have needed over a pound of weights to correct them. I tossed the tires in the trash with only 1200 miles on them. Actually, my trash won't take tires, but a shop in town did.

Here is my story. I put on a set of PRII's prior to going on a ride to Temecula to visit the winery and see the Ducati museum with about 50 other forum members. We then rode all over San Diego area for a couple hundred miles, had lunch then BeemerDon and I headed north towards Monterey. We stayed one night in a hotel after I became so tired I started blowing through red lights, Don, thinking I was listening to my GPS telling me to ride straight through red lights, suggested we stop before I get myself wasted permanently. The following morning we (Don & I) met up with Fairlaner, Ynotride, DjBill & John Dumke and headed north in a constant higher rpm ride up the 101 towards Monterey. Anyway, about half way up I started getting this weird bumping in my front end, causing my windshield to start shaking fairly violently. It felt as though I had picked up a large screwdriver, rock or bone in my front tire. I stopped to check it out and it appeared fine, so I figured it was the Dyna Beads. My front end only became really bad at speeds between 95-105. Anything slower or faster the front end was fine. So I kept it away from those list speeds. Although, by the time I got home, the vibration was so bad I pulled the tires off and took the front down to a local shop where they broke the tire loose so they could pour all of the beads out then placed the wheel on their balancing machine. It was bad, in fact they recommended I not use that tire any longer. So on went another set of PRII's I had in the garage.

To make my long story short, No More Beads, it just isn't worth it.

Recently I read a report in my MCN (Motorcycle Consumer News) an article where Dyna-Beads failed miserably in a test and even failed to show up for a second test or to provide them (MCN) their test data where they claim the Dyna-Beads actually work.

 

[RossKean]

Can someone please tell me why/how Dynabeads can possibly work to balance a tire. Do the beads magically "know" which is the light side of the tire and congregate there? Centrifugal force will force the beads to the portion of the tire that is furthest from the axle. If that happens to be the light side, great. If not, it might make a bad situation worse. I would expect that once the beads collected on the spot furthest out, the outward force they impart to the tire would stretch/push the tire further out-of-round (assuming there is enough weight to have any effect at all).

Maybe the manufacturers have the market cornered on some new laws of physics they never taught in school.

Haven't tried the Dynabeads but for what its worth, I have never experienced wobble/vibration with a reasonably new moto tire that was appropriately balanced with stick-on weights. Vibration from a worn, scalloped tire maybe, but not with a fresh one. For me, I don't see any reason to change from stick-ons. YMMV

Ross

 

[Big-D]

Can someone please tell me why/how Dynabeads can possibly work to balance a tire. Do the beads magically "know" which is the light side of the tire and congregate there? Centrifugal force will force the beads to the portion of the tire that is furthest from the axle. If that happens to be the light side, great. If not, it might make a bad situation worse. I would expect that once the beads collected on the spot furthest out, the outward force they impart to the tire would stretch/push the tire further out-of-round (assuming there is enough weight to have any effect at all).
Maybe the manufacturers have the market cornered on some new laws of physics they never taught in school.

Haven't tried the Dynabeads but for what its worth, I have never experienced wobble/vibration with a reasonably new moto tire that was appropriately balanced with stick-on weights. Vibration from a worn, scalloped tire maybe, but not with a fresh one. For me, I don't see any reason to change from stick-ons. YMMV

Ross

To answer your question quickly, the theory behind Dyna-Beads is Physics, where as the wheel turns the beads, being made out of porcelain, will become magnetized and find the out-of-round areas by locating the furthermost area of the tire. In Theory, they should (could) work. But in my case they did out.

To answer your second comment, the reason I tried the Dyna-Beads is because I bought my own mounting machine (manual) and wanted a way of balancing my wheels without paying some clown to do it for me. Well, I've learned my lesson and it ended up costing me by being a cheapskate!!

 

[RossKean]

...as the wheel turns the beads, being made out of porcelain, will become magnetized and find the out-of-round areas by locating the furthermost area of the tire. ...

Porcelain becomes magnetized?? Simple centrifugal force will move the beads to the point furthest from the center. If the furthest point is further because the rubber is a bit thinner (tire is perfectly round on outside but wall thickness may be a bit less in one area), there could be a positive effect. If the furthest point is just as heavy or further from the center because the tire is not perfectly round, the beads will yield the opposite of the intended effect.

 

[Big-D]

...as the wheel turns the beads, being made out of porcelain, will become magnetized and find the out-of-round areas by locating the furthermost area of the tire. ...

Porcelain becomes magnetized??

Yes, those little pesky porcelain beads become so magnetized you cannot get them off of you if you happen to spill any of those little bastards on yourself. They conduct static electricity and they become extremely magnetized. They get so bad, its like trying to separate Bust from Dolly without the use of a garden hose!! :haha:

 

[Phugedaboudet]

+1 for Me880's

getting tons more mileage out of them than the OEMs and only lost a little stickiness.

You answered your own question. METZLERS! :yahoo: I don't why more don't or won't run them, I like em alot!

 

[3dogs]

There is a reason that Dyna Beads are not used at the race track!!

 

[wheatonFJR]

Ya know, there is somethign to be said about they tried and true method of static balancing and stick on weights. They have been using them on the race track for years to speeds well over 200 mph. Just saying...

You mean the racing guys don't market Dyna-beads???

 

[FJRAE]

I just knew I'd find someone with s similar experience on the forum

I've used dyna beads on an 1800 vtx to 135 mph; silky smooth, on a cbr to 168; silky smooth, metzelers and shinkos respectively. The PR2s on the FJR; not so good, vibration starts at 85-90 mph and gets better above 120. After reading these posts and the manufacturers website, I'm guessing that they are sticking to the tire instead of rolling. I KNOW they work, but obviously they won't if they can't roll. Bummer, probably gotta yank the front tire again and see what's going on.

Very informative forum as always though

 

[funky]

How do them there beads know to go to the light side of the tire anyway?

 

[FJRAE]

https://www.youtube.com/watch?v=eq263AYgyYg

 

[Metric]

You never know when an old post will come back to life.

I've learned a bit more about this issue since 2009. This problem can happen with several different tires at random. What it appears to be is the lube that they apply to the tire mold during manufacturing. They (manufacturers) used to use cosmoline. It appears that maybe that is changing, maybe because of some environmental reason or cost, who knows. Tires that have a film of cosmoline weren't an issue. Some of the beads would turn black and get a bit bigger (some people have described that), but didn't STICK to the tire. What ever this new lube is they are using is causing the beads to become STUCK to the inside of the tire instead of floating. For those of you that have your own tire machines and are having problems, when you pulled your tire off the wheel you most likely saw that the beads were mostly black and 80 - 90% of them were 'glued' to the inside center of the tire. As the beads are getting stuck, the seriously screw up the balance of the tire....obviously.

The solution I came up with was pretty simple...baby powder. When I throw the beads in a tire now, I squirt a little bit of baby powder in the tire also. The baby powder ruins the sticky properties of the lube and then the beads work properly. So some day, I'll have a blow out and a big puff of white baby powder will signal that I have an issue to anyone behind me!

This is just another step if you want to keep the stick on weights off of your wheels. I suspect that for most people, its just another reason not to mess with it and go with the tried and true method of lead weights. Either way, its what ever you guys want to do. I just wanted to offer a solution for those of you who may have custom or polished wheels or who are doing their own tires at home and have liked the beads in the past but have had problems lately.

 

[timk]

Maybe the beads are getting wet/congealing. Do you dump compresser air often???

 

[FJR Flyer]

Try what you will, I still say its snake oil. Tried them and had a bad vibe in the front. Pulled them out and used standard weights with a static balancer and all was good. YRMV. But they ain't gettin' any more of my money.

 

[SouthernCruizer]

I've been using the beads for the last 4 or 5 tire changes. Pre bead use, my PR2 rear would last about 8K, and the front about 10K...post bead, the PR2 rear now lasts 10K, and the front about 12K, and I find the tires are smooth and steady, no vibes or wobbles....I'm a believer! :clapping:

 

[Zorlac]

I'm doubtful, but I'll admit that magnetized porcelain is rather intriguing. :blink:

I have enough stick-on lead weights to last my lifetime, I'm good.

 

[Metric]

How many of you are familiar with the fluid filled harmonic balancers that are used to keep the crank shaft in auto engines balanced? Different media and application, same concept. The theory is sound, for what ever reason it does work, using it in tires is just more difficult because of things like lubrication mucking up the works.

https://fluid-damper.com/

 

[charismaticmegafauna]

How many of you are familiar with the fluid filled harmonic balancers that are used to keep the crank shaft in auto engines balanced? Different media and application, same concept. The theory is sound, for what ever reason it does work, using it in tires is just more difficult because of things like lubrication mucking up the works.https://fluid-damper.com/

Liquid tire-balance has been used by the OTR trucking industry for 40 years (that I'm aware of...).

But..., from the Dunlop M/C tire site:

"Dunlop does not recommend the use of dry or liquid balancers/sealers and will not warrant tires into which these materials have been injected. Tire and wheel assembly balance must be checked with a balance stand or computer wheel balancer."

In the case of 'Dynabeads', you may be adding (extra) weight (un-sprung weight at that...) that may not be needed?

(unless -- you've balanced with fixed weights, removed them, and then added that amount of 'Dynabead' weight...? )