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Jstfrfun
| | Posted on Tuesday, May 12, 2009 - 04:59 pm: | 
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IMO having weights on your tires is just a fact I've grown accustomed to.
Some things you learn to live with. |
Reepicheep
| | Posted on Tuesday, May 12, 2009 - 05:02 pm: |
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The plastic bottle and drill demonstration (look for dynabeads on youtube) *is* fairly remarkable. |
Tdman77
| | Posted on Tuesday, May 12, 2009 - 07:31 pm: |
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Water in the plastic bottle would do the same thing. How about running water in your tires? I sure would be cheaper! |
Redefine420
| | Posted on Tuesday, May 12, 2009 - 09:08 pm: |
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This is in the FAQ on their website. It looks like they wouldn't perform so well on a dynamic balancer.
Can I put the tire on a balancer to see if it's working?
No. Dyna Beads operates on physics principles, and requires the tire assembly to be in motion against a road surface to detect the exact counterbalance position. An electronic balancer has a solid, fixed mount, and does not allow the tire to react to imbalance.
This is bothersome. It was hard enough trying to comprehend how they work, now they say you can't even test them to make sure they work. The plastic bottle trick is intriguing, but I'm not fully convinced. |
Phelan
| | Posted on Tuesday, May 12, 2009 - 09:14 pm: |
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I think the ones we had at WalMart could detect it if the operator spun the tire before putting the shroud down so that the operating speed could be reached IMHO. I need to order some and get Nick to test them, but I'm particularly broke at the moment.
(Message edited by Phelan on May 12, 2009) |
Blake
| | Posted on Wednesday, May 13, 2009 - 10:53 am: |
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The reason the beads won't work on a spin balancer is that they don't balance the tire.
That video is a stroke of genius in the world of hucksters. It can be very convincing, unless you actually analyze it.
1. The bottle magically appears to be balanced at high speed with the beads, but it isn't. If you look closely, you will see that the bottle is vibrating ferociously at its end in order to stay rotating about its center of mass there. It would do much the same without the beads.
2. The bottle and weight alone (without beads) were never allowed to spin up to the same high speed as it was with the beads, and conversely, the bottle with the beads was immediately spun up to a high speed. I wondered why? Apply some physics and we can find out why: If you quickly spin up the bottle with weight alone to the same high speed, it would also absolutely find its own balance since it is not supported by a rigid shaft, yet it would indeed vibrate about its own axis at the end of the bottle just like it did with the beads, just to a greater extent since without the beads the imbalance is a greater percentage of the effected mass (inertia).
A 20 gram (0.70 ounce) imbalance in a small diameter plastic bottle that weighs about the same or less will vibrate eccentrically more than if it had an additional 28 grams (1 ounce) of mass and the same imbalance. This is simple physics.
Ask the dynabead guy to please spin the bottle and weight alone up to a high speed just like he did with the beads. He won't, because if he did, the bottle will appear amazingly balanced, just like it did with the beads. It wasn't balanced then either.
Again, inspect the bottom of the bottle when it spins with the beads. The bottle still exhibits significant vibration at speed, just not the outlandish amount so slyly first shown at low speed without the beads. The imbalance is still there, but the addition of the beads about doubles the mass of the entire assembly and so the relative eccentric motion is as expected, diminished. If you double the mass of your front wheel/tire assembly while maintaining the same imbalance, it too will see diminished vibration, but the imbalance is still there.
3. The bottle is attached to the drill via a very flexible coupling, not a rigid steel axle and forks. Any such mechanism when spun up to an appropriate speed will self balance about its center of mass. No beads are required for that to happen. But it will vibrate.
4. The amount of beads added (1 oz) is HUGE compared to the mass and especially the rotational inertia of the bottle. You'd have to add pounds of beads to your tire in order to replicate the same effect. |
Fast1075
| | Posted on Wednesday, May 13, 2009 - 03:44 pm: |
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"balancing beads" are a real favourite with the 4x4 crowd...it is amazing...everything from the "dyna" beads to airsoft pellets...to steel balls, marbles, golfballs, you name it...all in an attempt to conquer the huge imbalances in large tires.
Personally, I always select a nice round tire (and reject any with an out of round problem) to begin with...and when mounted if they have any mass displacement problems (the tire is round when inflated, but during the layup process, the materials are improperly distributed..causing heavy spots) they are also rejected...the end result after selection is a tire that needs little in the way of added balance weight...I will admit that your typical "tire store" may not want to go along with such a selection process, I deal with a small store that I have done business with exclusively for over 30 years.
This post may not apply to quality motorcycle tires, but may be beneficial relaiting to larger tires.....the last set of tires that I put on my bike (Avons) did not need any added weight at all..perfect balance as mounted 
Without eating tons of bandwidth, those are the essentials....and thank you Blake, that was an excellent post. |
Reepicheep
| | Posted on Wednesday, May 13, 2009 - 03:46 pm: |
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Well, now we are getting somewhere. I have a drill and BB's out in the garage. Next time I can scare up a bottle, I'll give it a whirl  |
Jos51700
| | Posted on Wednesday, May 13, 2009 - 06:16 pm: |
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In the old days, tire shops used to shave tires to concentricity. Is that no longer an option? |
Tdman77
| | Posted on Wednesday, May 13, 2009 - 07:31 pm: |
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About 15yrs ago when I use to 4X4 we would take our tires to a shop the have them checked and shaved for roundness. Once the tires were mounted instead of using weights we would remove rubber from the tread blocks to balance them. I remember these beads back then but according to the guys who used them the didn't see any difference. Back then they still wanted you to balance the tire b4 using the beads. ??
I think I'm done here. It seems like there are the believers and non-believers. I will let it be. |
Redefine420
| | Posted on Wednesday, May 13, 2009 - 07:43 pm: |
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I think I'm done here. It seems like there are the believers and non-believers. I will let it be.
Same here. The first I heard of these magic beads was from the original post. I didn't realize that this "scam" has been going on for years. I'll keep my eye out for a test that proves they work. Until then I'll stick with the lead weights. |
Ebutch
| | Posted on Wednesday, May 13, 2009 - 08:54 pm: |
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http://www.innovativebalancing.com/motorcycle.htm |
Eshardball
| | Posted on Thursday, May 14, 2009 - 10:09 am: |
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Blake. Great post. I don't have the knowledge of subject to offer realistic counterpoint. I am almost tempted to buy them and send them to Phelan to test on a spin balancer. I have always static balanced my tires with good results. I just didn't want to poo poo the technology without having some credible evidence |
Gowindward
| | Posted on Thursday, May 14, 2009 - 10:14 am: |
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Blake, perhaps your right? |
Phelan
| | Posted on Thursday, May 14, 2009 - 12:32 pm: |
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+1 on what Eric said. I should learn to quit posting when I'm drunk  . I'm not convinced 100% either way, but you do make a good argument Blake. |
Id073897
| | Posted on Thursday, May 14, 2009 - 02:15 pm: |
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Ask the dynabead guy to please spin the bottle and weight alone up to a high speed just like he did with the beads
http://www.youtube.com/watch?v=5BKRrNVriao |
Blake
| | Posted on Friday, May 15, 2009 - 10:10 am: |
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Gunter,
In that video, the setup is rigged so that the bottom of bottle will only be swung around like a ball on the end of a string, versus rotate about it's own center of mass. It is grossly deformed off-axis to begin with so as to prevent the required stable (yet vibrating) rotation. It is not the same setup and is subject to completely different initial conditions and boundary constraints. Put beads in that new setup with the same imposed initial conditions/boundary constraints, and you'd see the imbalance worsen.
I guess I need to do my own bottle spinning youtube video to expose this nonsense. |
Eshardball
| | Posted on Friday, May 15, 2009 - 11:01 am: |
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So I guess that buying the beads and testing them on a spin balancer will be a waste of time and money |
Phelan
| | Posted on Friday, May 15, 2009 - 11:06 am: |
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I'll test them if anyone wants to send them to me, but I'm too broke to buy them myself. |
Essmjay
| | Posted on Friday, May 15, 2009 - 11:19 am: |
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Sounds like a job for the Mythbusters... |
Dave_02_1200
| | Posted on Friday, May 15, 2009 - 11:50 am: |
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Essmjay is right!
Mythbusters is the right venue - but not on my motorcycle.
Especially since I bought a Marc Parnes wheel balancer a while back.
It works incredibly well due to very low friction bearings and cost just over $100.00.
See his balancer at www.marcparnes.com.
It is simple and very well made and is easy to use.
I have used several types of balancing tools over the years and this is the best one I have ever seen. |
Loki
| | Posted on Friday, May 15, 2009 - 12:31 pm: |
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**CAUTION** momentary thread jack is now in progress.
For those on a tight budget. Harbour Freight as a static balancer for cycle wheels. It works and it works well. It does work with the Buell set-up. Also have adapters for Ducs, BMW and certain Hondas.
I have gone so far to do this. Check the wheel with no pulley or rotor. Install said pulley and rotor and recheck. Do it without the valve and then again with the valve installed.
As a general rule I now check and mark the heavy spot before I mount the tire.
**now back to the original program in progress. |
Andymnelson
| | Posted on Friday, May 15, 2009 - 01:04 pm: |
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Duly submitted to MythBusters:
http://community.discovery.com/eve/forums?a=tpc&s= 6941912904&f=9701967776&m=58719124101&r=5871912410 1#58719124101
Some NON-BIASED comments encouraging them to do the Myth would be helpful. |
Reepicheep
| | Posted on Friday, May 15, 2009 - 01:20 pm: |
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The "real" dynabeads are ceramic, which is supposedly so they wear better and don't rust. But if you just want to do the "drill and plastic bottle test", BB's ought to work just as well, if not better. |
Redefine420
| | Posted on Friday, May 15, 2009 - 02:09 pm: |
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I guess I need to do my own bottle spinning youtube video to expose this nonsense.
Please do Blake! Now I just need to know what the verdict is on this. I'm going to submit a request to mythbusters too. |
Jayvee
| | Posted on Friday, May 15, 2009 - 07:05 pm: |
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Blake, no offense, but that's a pretty non-technical explanation, coming from you. It seems like some assertions, observations, and speculation/prediction, without much science to explain why this cannot work.
If stick on wheel-weights can balance the tire, would it behave any differently if they were mounted inside the tire? So the difference is whether a non-fixed wheel-weight would 'automatically' balance the tire. Otherwise, only the shape and consistency of the wheel weight is different. Seems like that has been demonstrated, if not 'proven'. Some Harleys have similar things added to their cranks, clutch baskets, and the like.
As far as 'pounds' of balancing beads needed I don't see why it would need to be more than the same tire's balancing lead weight. Perhaps even slightly less, because the weight it closer to the perimeter, by the height of the tire.
I'm still looking for some of those 'racing' titanium wheel weights for my bike, if anybody knows where I can get some.... |
Ebutch
| | Posted on Friday, May 15, 2009 - 08:30 pm: |
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BB,s would really tear things up inside!That,s why cer. beads. |
Dave_02_1200
| | Posted on Saturday, May 16, 2009 - 07:33 am: |
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Racing titanium wheel weights would reduce unsprung weight, right?
Of course these would have to be custom made for each application.
Seriously, why not just use some simple stick-on lead weights?
Properly done, they do the job quite nicely without all the infomercial hype and voodoo theory behind balancing beads.
If "dynamic" balancing medium really was the way to go, water would be a cheap and readily available solution.
I am staying with the proven lead weights - at least as long as long as they are still legal. |
Phelan
| | Posted on Saturday, May 16, 2009 - 10:54 am: |
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Yeah! Titanium wheel weights! 'cuz 3/4 oz of titanium is way lighter than 3/4 oz of lead! |
Ebutch
| | Posted on Saturday, May 16, 2009 - 11:37 am: |
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I like diammonds,How many carats = a oz? |
Eshardball
| | Posted on Sunday, May 17, 2009 - 11:45 am: |
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141.5. Nothing like having $500,000 in wheel weights on your $5000 motorcycle |
Loki
| | Posted on Sunday, May 17, 2009 - 01:40 pm: |
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"Some Harleys have similar things added to their cranks, clutch baskets, and the like."
But that is a captured(read fixed) balancing weight.
When it comes to things described as "snake oil" everybody's experience with it is different. It works for some and others it does not. If you truly believe that it works, then it will, for you. For those that are non-believers it will never work as described. |
X1whunter
| | Posted on Sunday, May 17, 2009 - 02:45 pm: |
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POS, pure oh s'hit crap! SNAKEOIL for sure! |
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