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Thread: Dyna beads R1200GS

  1. #16
    Cam Killer marchyman's Avatar
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    Quote Originally Posted by deilenberger View Post
    something about weight moving to the light spot on a rotating mass just doesn't seem to work for me. I believe MCN also had a bit of a problem with that theory.

    As well they should... that's not the theory behind how the beads work.

    The beads do nothing to balance wheels/tires. What they may do is balance the effect that an out of balance wheel/tire has on your suspension. It is the up/down of your suspension that may be balanced, not the rotating wheels. Without a moving suspension the beads do nothing.

    Note: I don't use them and likely never will for various reasons. I just wish that someone who understood what they were supposed to do would rig up a reasonable test. Putting a wheel with beads on a spin balancer that measures axle strain does only shows that the people running the test (yes, I'm talking about MCN) are clueless about how the beads could work. It doesn't help that the beads are marketed as something that will balance your wheels/tires. They can do no such thing.

  2. #17
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    Quote Originally Posted by marchyman View Post
    As well they should... that's not the theory behind how the beads work.

    The beads do nothing to balance wheels/tires. What they may do is balance the effect that an out of balance wheel/tire has on your suspension. It is the up/down of your suspension that may be balanced, not the rotating wheels. Without a moving suspension the beads do nothing.

    Note: I don't use them and likely never will for various reasons. I just wish that someone who understood what they were supposed to do would rig up a reasonable test. Putting a wheel with beads on a spin balancer that measures axle strain does only shows that the people running the test (yes, I'm talking about MCN) are clueless about how the beads could work. It doesn't help that the beads are marketed as something that will balance your wheels/tires. They can do no such thing.
    I'm always a bit slow (hey I have a Polish ancestry and grew up in a small town in Nebraska - that's like two strikes right out of the gate, right). Here's where I'm confused. If beads balance out the up/down effect that an out of balance wheel/tire has on the suspension, and the axle of the wheel/tire is rigidly attached directly to the bottom part of the suspension, wouldn't that mean the beads were distributing themselves inside the tire in a way that also stopped the unbalanced wheel from going up and down (due to the inbalance)?

    Other than that the wheel needs to be rotating for it to happen (I suppose that's why they use DYNA in dynabeads), how is that any different than using weights on the rim to stop the up and down movement of the wheel/tire due to an inbalance?
    Last edited by alzyck; 06-22-2010 at 06:50 PM.

  3. #18
    A bozo on the bus deilenberger's Avatar
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    Quote Originally Posted by marchyman View Post
    As well they should... that's not the theory behind how the beads work.

    The beads do nothing to balance wheels/tires. What they may do is balance the effect that an out of balance wheel/tire has on your suspension. It is the up/down of your suspension that may be balanced, not the rotating wheels. Without a moving suspension the beads do nothing.
    The moving suspension part is fine - but a heavy spot will try to move outward harder then a light spot - so when the heavy spot crosses the movement axis of the suspension - the wheel will tend to move up (if the heavy spot is UP) or down (if the heavy spot is down.)

    That's a given. What isn't a given is exactly HOW and WHY the Dynabeads would tend to go to the opposite side from the movement to counteract the movement.

    So - what is the theory behind how the beads work?

    Note: I don't use them and likely never will for various reasons. I just wish that someone who understood what they were supposed to do would rig up a reasonable test. Putting a wheel with beads on a spin balancer that measures axle strain does only shows that the people running the test (yes, I'm talking about MCN) are clueless about how the beads could work. It doesn't help that the beads are marketed as something that will balance your wheels/tires. They can do no such thing.
    Actually IMHO - that's a good test. The "spin balancer" actually measures displacement forces on the center axle going through the mounted wheel. It does this when the wheel is MOVING - not when it's stationary.

    Problem with many motorcycle ones (like the Snap-On one I usually use) - is the rotational speed may not be enough to trigger the magical effects of Dynabeads..

    But - automotive spin balancers are usually electrically driven - and will spin a tire up to 50-60 MPH to measure imbalance. It would seem that if the effect is real - Dynabeads could be shown to work on a car tire mounted in a high-speed dynamic spin balancer.

    So far - I've never seen that happen. Has it? Inquiring minds want to know..
    Don Eilenberger http://www.eilenberger.net
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  4. #19
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    Quote Originally Posted by deilenberger View Post
    ...
    That's a given. What isn't a given is exactly HOW and WHY the Dynabeads would tend to go to the opposite side from the movement to counteract the movement.
    ...
    I don't get why that would be such a mystery. The beads act like a low mass fluid inside the tire. Been a while on my physics, but when the heavy spot tries to move outward like you described, isn't it accelerating away from the beads directly below the heavy spot on the inside surface of the tire? The beads are fluid and they flow/roll back towards the light spot on the tire as the heavy spot accelerates away.

  5. #20
    Registered User mpmarty's Avatar
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    Snake Oil! It only works if you "believe" in it.
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  6. #21
    Cam Killer marchyman's Avatar
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    Quote Originally Posted by deilenberger View Post
    Actually IMHO - that's a good test. The "spin balancer" actually measures displacement forces on the center axle going through the mounted wheel. It does this when the wheel is MOVING - not when it's stationary.
    Beads need suspension movement, not the forces that would generate that movement, to have a chance at working. The beads DO NOT BALANCE THE WHEEL. They may balance the effects that an out of balance wheel have on a moving suspension by changing the the coupled mass of the wheel.

    An out of balance wheel will tend to compress the suspension as the heavy point is in line with the spring. When it does this the tire, for a brief bit, moves away from the beads that are at the top of the arc. For that brief bit the beads at the bottom are coupled to the wheel but the beads at the top are not. The mass changes. That's the theory as I understand it. I think I see how it can work. But....

    • how fast does the wheel need to spin?
    • how much suspension movement is needed?
    • what effect has suspension movement not associated with an out of balance wheel?
    • how well/fast to the beads react to varying wheel speeds?
    • what, if anything, do beads do to the inside of your tire?
    • since the wheel is not balanced, is there extra wear on wheel bearings?


    Those are a few of the unanswered questions that keep me from using beads.

  7. #22
    Dale Rudolph
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    Let's say that dynabeads do work. Don't they all settle on the bottom of the tire
    each time the bike comes to a stop? Seems like you would have a very out of
    ballance tire each time you start off until you reach a speed where they would start to work.

  8. #23
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    Quote Originally Posted by DRUDOLPH148006 View Post
    Let's say that dynabeads do work. Don't they all settle on the bottom of the tire
    each time the bike comes to a stop? Seems like you would have a very out of
    ballance tire each time you start off until you reach a speed where they would start to work.
    Very true. IIRC, the dynabead guys say the beads are working completely somewhere around 25 MPH. Low enough you don't notice the imbalance.

  9. #24
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    FWIW, "How it Works" from the dynabead site...

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

  10. #25
    Unfunded content provider tommcgee's Avatar
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    Quote Originally Posted by alzyck View Post
    FWIW, "How it Works" from the dynabead site...

    http://www.innovativebalancing.com/HowItWorks.htm
    I'm open to seeing some proof. Testimonials and graphics are not proof.
    Salty Fog Rally 2007, 2009, 2011, 2012, AND LOOKING FORWARD TO 2014!

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  11. #26
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    Quote Originally Posted by tommcgee View Post
    I'm open to seeing some proof. Testimonials and graphics are not proof.

    So, who said the testimonials and graphics were proof of anything?

    There's been an ongoing discussion of how dynabeads work with different opinions on if and how they work. The link provided an explanation from the perspective of the company that makes them. Nothing more or less.

    I'll go have my beer now.

  12. #27
    2011 R1200RT ka5ysy's Avatar
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    Quote Originally Posted by alzyck View Post
    So, who said the testimonials and graphics were proof of anything?

    The current administration in Washington. Ask them.
    Doug, 2011 R1200RT Polar Metallic
    MSF #127350 NAUI #36288

  13. #28
    1aretea
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    It seems like the people who tried Dyna Beads, like them. The others want to disprove them.

  14. #29
    Unfunded content provider tommcgee's Avatar
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    Quote Originally Posted by 1aretea View Post
    It seems like the people who tried Dyna Beads, like them. The others want to disprove them.
    I'm one who tried them and took them out 3 days and 300 miles later.
    Salty Fog Rally 2007, 2009, 2011, 2012, AND LOOKING FORWARD TO 2014!

    -Tom (KA1TOX)

  15. #30
    From MARS
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    Quote Originally Posted by tommcgee View Post
    I'm one who tried them and took them out 3 days and 300 miles later.
    Why?

    I've been using them for over a year, in three sets of tires (both tubed and tubeless) on my GSPD, with very good results.

    Tom

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