Interesting prospective inside a moving tire.
GoPro inside a tire, with balance beads
- Thread starter Mainia
- Start date
I don't agree. Totally random effects.
Now that was very cool. Seeing the inside of a moving tire and how much it flexs while driving. Very neat
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F
From the fixed camera on the inside of the rim, we can only see one spot inside the tire, so it's possible that the beads have indeed positioned themselves heavier or lighter in certain areas within the tire accordingly.
As a tire engineer, here's what I noticed in the video.
That tire has a tread separation. Notice that when he pries on the crack early in the video, you can see the belt edges. He shouldn't have driven this tire over 50 mph.
On the balancer, if the beads were working as advertised, he should have gotten the same exact reading - he didn't. That says to me the balance beads didn't work!
It's unclear, but it sounds like he didn't balance the assembly before he mounted it on the car.
Here's what he should have done:
1) Mounted the tire on the wheel and balanced it.
2) Marked on the tire where the valve was.
3) Mount the camera, then remounted the tire in exactly the same place, and balance the assembly without the beads.
4) Add the beads and see if there was a change in balance. There should have been an improvement.
5) Add the weights indicated, then repeat the balance. It should be zero and should stay zero regardless of how many times you balance the assembly.
6) Drive the car up to 70 mph, then coast down and note where the vibration is worse. Note the vibration level. There shouldn't be any!
Please note: Vehicle suspensions have a resonant frequency between 50 and 70 mph. That's why the coast down.
That tire has a tread separation. Notice that when he pries on the crack early in the video, you can see the belt edges. He shouldn't have driven this tire over 50 mph.
On the balancer, if the beads were working as advertised, he should have gotten the same exact reading - he didn't. That says to me the balance beads didn't work!
It's unclear, but it sounds like he didn't balance the assembly before he mounted it on the car.
Here's what he should have done:
1) Mounted the tire on the wheel and balanced it.
2) Marked on the tire where the valve was.
3) Mount the camera, then remounted the tire in exactly the same place, and balance the assembly without the beads.
4) Add the beads and see if there was a change in balance. There should have been an improvement.
5) Add the weights indicated, then repeat the balance. It should be zero and should stay zero regardless of how many times you balance the assembly.
6) Drive the car up to 70 mph, then coast down and note where the vibration is worse. Note the vibration level. There shouldn't be any!
Please note: Vehicle suspensions have a resonant frequency between 50 and 70 mph. That's why the coast down.
That's pretty horrible. I can feel anything more than about 0.75oz out of balance.
I have also noted that some roads will produce what feels like an out of balance tire, with certain tread patterns. For example, my CC2's feel off at around 70-75mph on one stretch of road in particular where I live, but take them anywhere else and it's smooth as glass. I have noted this in multiple vehicles with CC2's on them.
What I always wondered was if the beads simply swamped out the imbalance. The closer the balancing weight is to the center of the wheel, the more mass is required to fix an imbalance—but if you could some get it right under the tread, then not much should be needed, right? So if you needed an oz at the bead, it should be less at the tread—but if you gobbed in a couple ounces of weight, distributed around the circumference of the tire, it might simply be larger than source of small weight error.
Wonder if beads work on tires that are out of round or have flat spots.
Wonder if beads work on tires that are out of round or have flat spots.
A friend of mine tried these in a Jeep with 37” tires. He said that once up to speed, beads work great. But if you started turning while at speed, they shook pretty notably. Also said it was irritating that after stopping, at every start the vehicle was out of balance until they settled down.
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Cool experiment. I think it works best at higher speeds and less at lower speeds.
No opinion on his conclusions, I do really appreciate that he went to the effort of putting a GoPro in a tire and posting the video.
I though to balance something you have to mount a weight that's stationary to something else. If you let it swirl or move around like those bead does, it is just going to cause more imbalance.
Nice to see how the inside of a tire looks like.
Nice to see how the inside of a tire looks like.
