Optimization of rims and tires
Optimization should be a standard procedure when balancing.
We have two seasons of tire replacement a year, for the summer and winter seasons. Nowadays, it is a very "hot" period of every vulcanization plant, and you have to make an appointment a few days in advance. Therefore, services at this time can be carried out with not fully due attention and accuracy of the service employee, which is caused by an excess of work, lack of time and the desire for maximum profit in this very seasonal job. Optimizing the tire to the rim should be standard procedure when balancing the entire wheel. Of course, optimization requires additional time, which is not enough when there is a line of vehicles in front of the workshop waiting for their turn to change tires.
Most of us have certainly met, if not in their own car, at a friend or neighbor's place with a lot of weights stuck to the rims. This is largely due to a poorly performed service and a lack of wheel optimization. In a smaller percentage, but it should also be taken into account, the reason may be manufacturing defects, damage to the rim or tire. Today we will describe what is and how the process of optimizing the tire in relation to the rim should be carried out.
First - check the visual condition.
Rims and tires are underweight and there is no situation in which they do not need to be balanced. This is what devices such as wheel balancers are for. Before an employee starts putting on tires, he or she should visually inspect the rims and tires for any mechanical damage such as dents, rim dents or, in the case of tires, commonly known as "bumps".
Photo: dented rim edge.
Correct assembly of the rim on the wheel balancer is the key to success.
In the case of rims, it is always worth checking the mounting plane of contact between the rim and the car hub. Both these elements should be cleaned, and free from rust tarnish or, for example, excess aluminum material in the case of "allus". The planes must fit perfectly together.
Photo: graphics from a plane with chipping.
The very method of mounting the aluminum rim on the wheel balancer is of great importance. From the inside, where the rim touches the hub, it should slide over the conical retainer. From the outside, where the lid with the logo of the car brand or rim manufacturer is plugged in with a FLAT rubber element. It is caused in most cases by the method of machining aluminum rims. The lion's share of aluminum rims is made by low-pressure die casting, which then requires additional processing with CNC machines. The inner side of the wheels from the hub side is milled, so it can be placed on a CONE, the outer side of the cap does not need to be processed in such a way, which may result in the crooked mounting of the rim on the balancing device when using a CONE. Therefore, you need to press the rim with a flat rubber element.
The ideal is to center the rim on the mounting holes in the rims with the pressure plate, unfortunately it is very, very rarely used.
Photo: mounting method on the balancer.
Optimization of the tire in relation to the rim.
What is the meaning of TIRE OPTIMIZATION WITH RESPECT TO RIM? It's nothing complicated, it's just finding the optimal position of the tire on the rim. As we mentioned earlier, the rim and the tire are underweight and not perfect. If these underweight tires and rims overlap, there is a huge result in grams, which should be eliminated with weights. OPTIMIZATION is the rotation of the tire in relation to the rim. If the vulcanizer does not use the program in the balancing machine for this purpose, then the tire opposes the rim by 180 degrees first, then verifies the deviations. He can repeat it, this time 45 degrees. Using the balancer, it will show us the perfect mutual position! In summary, you should deflate the tire several times, smash the tire, turn it, pump air and balance the wheel. This is laborious and time-consuming and therefore this practice is rarely used during tire changing seasons. It is more profitable for vulcanizers to stick additional weights to the rim than to twist the tire and occupy one of the work stations.
Photo: rim on the balancer.
Below we present you an example of an optimization instruction provided by the manufacturer of one of the leading Polish brands of balancing machines, UNI-TROL.
Optimization - the first stage.
The first step is to set the empty rim in motion on the wheel balancer (without the tire), this will allow us to determine its technical condition, you can see with the naked eye whether the rim is turning straight. We can also see how many grams are needed to balance the rim itself. We will find out whether a large underweight is the fault of the rim or the tire. Remember that the use of tire pressure sensors will also result in a greater underweight. Don't worry, the optimization process is still ahead of us!
Remember that the deviations are more important than the underweight itself !!! We should compensate for the underweight with weights, larger deviations are the replacement or repair of the rim. For Aluminum Wheels, the vertical deflection should not exceed 0.5 mm.
Photo: rim on the balancer.
Video: measuring deviations.
Optimization - the second stage.
The second stage, by restarting the measurement cycle, we will allow the machine to calculate the size and position of the tire and rim imbalances and indicate their optimal position in relation to each other.
The balancer software will show you how to turn the rim in relation to the tire so that the underweight is reduced as much as possible! At this point, for larger sizes, the tire has to be removed from the rim beads to allow it to turn, which is why most vulcanizers do not do it, it is time-consuming, and we will not count the customer twice. The vulcanizer says: "You bought poor quality products and that's it."
In our case, the profit = the smaller number of grams needed to balance the wheel is as much as 45 grams!
Photo: gram quantity profit.
Summary.
Continental recommends that you rebalance the wheel when changing a tire on a wheel. In this way, we avoid vibrations and premature wear due to imbalance of the rotating rim with the tire.
As part of routine vehicle maintenance, drivers should have the wheels balanced after 5,000-10,000 mileage. km or after 1-2 years (whichever comes first).
Even the largest plant with the most modern and expensive equipment will not replace an experienced and reliable specialist with experience. We can check a few things ourselves before taking the rims and tires for vulcanization, we can also observe the work of the vulcanizer and see how he approached the tire assembly service.
Author: Michał Okrągły