Tire balance bead experiment - do they work?

[CanAmAndMore]

Long ago I tried in my motorcycle tires.
They were horrivle!
I couldn't stand it any more, so a few weeks later removed them.

 

[billt460]

I wish one of our physicist here would explain why the beads find the opposite side of the imbalance. My non-physicist brain thinks the beads would find the same side as the imbalance and make it worse.

I'm trying to understand the logic behind this. A T-Wrench spinning in zero g inside the ISS. Why is it constantly changing?

 

[wwillson]

I'm trying to understand the logic behind this. A T-Wrench spinning in zero g inside the ISS. Why is it constantly changing?

For the same reasons balance beads find the opposite of the imbalance, nobody seems to know

 

[BornSlippy]

Newton's Third Law?

 

[wwillson]

Newton's Third Law?

Could you go a bit deeper?

 

[BornSlippy]

Could you go a bit deeper?

Every action has an equal and opposite reaction.

 

[opublic]

I'm trying to understand the logic behind this. A T-Wrench spinning in zero g inside the ISS. Why is it constantly changing?

The fourth comment on the video explains it very well:

The object is precessing, with zero total external torque. It's generally true that the rate of precession is high for small moment of inertia I, and small for high I. About an axis through the shaft, I is large. About an axis parallel to the handle, I is small.

i) While it is rotating with its shaft nearly parallel to the angular momentum L , its moment of inertia is large, so it precesses slowly. Hence this rotation state seems approximately stable (but in fact is slowly varying).

ii) Once the precession takes the long axis (the handle) nearly parallel to the angular momentum L, its moment of inertia about this axis is small, so it precesses rapidly. In fact the precession is so rapid that we hardly notice it: it seems to 'flip' rather quickly to the

iii) next state with its short axis (high I) nearly antiparallel to the angular momentum L, it precesses slowly so that this seems 'stable'.

 

[wwillson]

I wish one of our physicist here would explain why the beads find the opposite side of the imbalance.

My next door neighbor taught physics and did research at the local university for 30 years. I asked him how balance beads work, to which he promptly explained it has to do with the relationship between the center of mass and the center of rotation. The beads will move to reduce the distance between the center of mass and the center of rotation. He offered to model it for me mathematically. I said that I would take his word for it.

 

[t1snwrbrdr12]

I just had to use some yesterday on a set of LT tires. It was for an f550 stake body truck. When I went to mount them on our balancer, the hub adapter for the trucks hub size didn’t work, it was improperly machined, so it wouldn’t slide over the shaft of the balance machine. Tried filing it but wasn’t getting anywhere so i broke a bead down of each and installed 3oz if equals beads in each, along with the proper stem cores etc.

Took it for a ride and it seemed fine, although with a full framed heavy duty vehicle idk if I would’ve felt a vibration anyway.

 

[ProbeGT]

Didn't work at all on my Jag's 245/45R18. If anything, the steering wheel vibration got even worse. Waste of time and money.

 

[Malo83]

Tried these on my Silverado, 15x8 front and 15x10 rear rims, still get a shake between 50/65 mph.

Wheel Balancer 200-221 from Centramatic

Centramatic is an industry leader in wheel balancing technology!

www.centramatic.com

 

[someonesomewhere]

I just had to use some yesterday on a set of LT tires. It was for an f550 stake body truck. When I went to mount them on our balancer, the hub adapter for the trucks hub size didn’t work, it was improperly machined, so it wouldn’t slide over the shaft of the balance machine. Tried filing it but wasn’t getting anywhere so i broke a bead down of each and installed 3oz if equals beads in each, along with the proper stem cores etc.

Took it for a ride and it seemed fine, although with a full framed heavy duty vehicle idk if I would’ve felt a vibration anyway.

Probably a great application for these, ginormous trucks.

 

[sweezy722]

I tried them several years ago. They worked great on a straight smooth road. They did not work below 35 mph and did not work as well on really rough roads and hard curves. I threw them away and now use a Harbor Freight bubble balancer. There is a learning curve with the bubble balancer but it is all I will use now.

 

[t1snwrbrdr12]

Probably a great application for these, ginormous trucks.

Our big truck guys use the same pack of balance beads in 22.5” wheel/tires. Unless they’re using a couple packs per wheel, I can’t see that being enough.

I just assumed the 3 oz was sufficient. Tried finding charts online but nothing listed LT tire sizes (245/something/17). Everything was 17.5, 19.5, actual heavy truck sizes. I think it said a 8-9” 17.5” wheel / tire took 3oz so figured mine were in that neighborhood.