Red_Bean_Bun
Well-Known Member
Changed my tyres to CSC5P and new set of rims recently. After the change, I had problems with vibrations. Decided that wheel balance should be checked first before going into the control arms etc for the vibration issues.
Read up on the road force method of wheel balancing and decided this could help with the problem with my steering wheel vibrations while traveling around 100 kmh. It is the rage in the US along with walnut blasting so what the heck.
Found that there are only a couple of road force balance WS here. Visited one today. The Hunter GSP9700 machine there seems to be able to detect a number of issues with my new rims and tyres -
- Weights and its location
- High and low point of the tyre and rim
- lateral forces
The way the machine work is by applying a 750kg force on the tyre simulating road conditions. It also tested all kinds of other parameters like the shape of the tire and rim. The apparatus had arms that the mechanic had to tap on the tyre and rim while it turns the tyre and rim number of times. Then it starts spinning while a graphical display shows the test progress and the type of test it is undergoing. Very nice graphics.
In my case, one wheel had problems and failed to pass the tests. The benchmark is 9kg of force max but mine had it at 13kg. The higher the force, the higher the likelihood for vibrations. The Hunter prompted for a more detailed test which the mechanic obliged. After the test, it highlighted with a laser light across a part of the tyre.
The mechanic proceeded to identify the high point of the tyre (laser beam line) and low point of the rim. They marked the points and reinstalled the tyre so both points aligns.
Then it was tested again and the force was reduced to just 6.5kg. The general idea is that both the rim and the tyre are not 100% round. If the high and low points are totally out of phase, you literally have an oval wheel. By aligning the high and low points, the oval ness is sort of canceled out making the wheel "rounder. And the rounder it is, the smoother the ride.
The other wheels had the laser light showing different locations for the weights and it had a different opinion of the amount of weights as well compared to the original weights.
An interesting feature called Smart Weight. The Hunter is able to help the mechanic put the weights on in a way that help cancels out the imbalances resulting in less weights being used and distribute the weights in a more even manner e.g not 10 blocks of weights in a row on one side of the rim but reduce it to maybe 6 have have 3 weights in a row on one side and the other 3 placed on another side. An experienced mechanic can also do this. But experience is arbitrary and mood dependent. Machines have no moods.
The whole process took about 45 minutes. After which, I took the car out for a ride to the airport. The ride is way smoother and the vibrations are reduced by about 90%.
And something pleasant occurred to me during the ride - the road noise reduced substantially. I could actually hear the lyrics of some songs being played when I was on some types of bitumen where before I had so much noise. I think it was about on average 5 decibels less based on readings on my iphone.
Btw, I had the car jacked up while I was there and inspected the control arms. No leaks and no loose ends. So will not be replacing those.
Read up on the road force method of wheel balancing and decided this could help with the problem with my steering wheel vibrations while traveling around 100 kmh. It is the rage in the US along with walnut blasting so what the heck.
Found that there are only a couple of road force balance WS here. Visited one today. The Hunter GSP9700 machine there seems to be able to detect a number of issues with my new rims and tyres -
- Weights and its location
- High and low point of the tyre and rim
- lateral forces
The way the machine work is by applying a 750kg force on the tyre simulating road conditions. It also tested all kinds of other parameters like the shape of the tire and rim. The apparatus had arms that the mechanic had to tap on the tyre and rim while it turns the tyre and rim number of times. Then it starts spinning while a graphical display shows the test progress and the type of test it is undergoing. Very nice graphics.
In my case, one wheel had problems and failed to pass the tests. The benchmark is 9kg of force max but mine had it at 13kg. The higher the force, the higher the likelihood for vibrations. The Hunter prompted for a more detailed test which the mechanic obliged. After the test, it highlighted with a laser light across a part of the tyre.
The mechanic proceeded to identify the high point of the tyre (laser beam line) and low point of the rim. They marked the points and reinstalled the tyre so both points aligns.
Then it was tested again and the force was reduced to just 6.5kg. The general idea is that both the rim and the tyre are not 100% round. If the high and low points are totally out of phase, you literally have an oval wheel. By aligning the high and low points, the oval ness is sort of canceled out making the wheel "rounder. And the rounder it is, the smoother the ride.
The other wheels had the laser light showing different locations for the weights and it had a different opinion of the amount of weights as well compared to the original weights.
An interesting feature called Smart Weight. The Hunter is able to help the mechanic put the weights on in a way that help cancels out the imbalances resulting in less weights being used and distribute the weights in a more even manner e.g not 10 blocks of weights in a row on one side of the rim but reduce it to maybe 6 have have 3 weights in a row on one side and the other 3 placed on another side. An experienced mechanic can also do this. But experience is arbitrary and mood dependent. Machines have no moods.
The whole process took about 45 minutes. After which, I took the car out for a ride to the airport. The ride is way smoother and the vibrations are reduced by about 90%.
And something pleasant occurred to me during the ride - the road noise reduced substantially. I could actually hear the lyrics of some songs being played when I was on some types of bitumen where before I had so much noise. I think it was about on average 5 decibels less based on readings on my iphone.
Btw, I had the car jacked up while I was there and inspected the control arms. No leaks and no loose ends. So will not be replacing those.
