FAQ 01 Why are wheels being balanced?
04 When to use metal valves or rubber valves?
Properly balanced wheels are essential for driving comfort and long tire life. Out-of-balance wheels may cause vibration that results in driver fatigue and contributes to increase tire wear and unnecessary wear of vehicle suspension. Tires should be balanced before being put on the rims for the first time, when changing wheels, or after repair. Yet vibration may also be down to misaligned wheels or mechanical prob- lems. 02 How to balance tires? Each tire and wheel have a certain mass distribution. If asym- metries in mass distribution are not balanced using correction weights, there is an imbalance, which will inevitably lead to vibration, vertical impacts, and shimmying wheels. For balan- cing, the tire-wheel assembly is mounted onto a balancing machine and then rotated, with sensors measuring the weight distribution of the wheel. After the first measurement, the balancer indicates to the tire fitter where and how many weights to place on the wheel. After attaching the wheel weights, the tire-wheel assembly is spun and measured for a second time. If the right weights have been put in the correct place on the wheel, the balancer reports that everything is in order.
As a rule, metal valves are more expensive than rubber valves. Another disadvantage of the relatively non-flexible metal valves is the risk of breakage when hitting other objects, such as the curb. Whether to use metal or rubber valves is a question of safety. Metal valves are better suited for higher speeds because they withstand centrifugal force. In other words, they do not flex or bend as much as valves made of rubber. That is why rubber valves have normally only been approved for a speed of 210 km/h at the maximum , as specified by the manufacturers.
In many cases, enclosed expert reports stipulate the use of metal valves with the rims.
Damage may also become noticeable only very gradually, e.g. in the event of micro- cracks in the valve.
05 How often must valves be changed? Tire valves should be replaced regularly. Environmental conditions cause the rubber to wear down over time, resulting in a loss of pressure, which puts a high strain on the tire. It is a security aspect, especially when it comes to normal valves without TPMS. Best replace valves with every summer/winter tire change. Customers should never store valves for more than 5 years and valves should not be exposed to light and heat. In addition, tire pressure should be checked from time to time.
Damage may also become noticeable only very gradually, e.g. in the event of microcracks in the valve.
It has become standard practice to use either self-adhesive or hammer-on weights made of steel or aluminum.
06 What must be observed when fitting tires? The rim must neither be damaged nor have sharp edges that may damage the valve. Of course, professional tools must be used.
03 Tightening of wheel bolts using the right torque. In order to avoid damaging bolts and nuts and to avoid com- promising driving safety, they must always be torqued to spe- cification. If you apply too low a torque, nuts or bolts can work themselves loose. If, on the other hand, nuts or bolts are over-torqued, they may stretch and, in the worst case, break under load. What is more, the thread of the nut or even the aluminum rims may be damaged.
Adolf Würth GmbH & Co. KG · 74650 Künzelsau · T +49 7940 15-0 · F +49 7940 15-1000 · www.wuerth.de · info@wuerth.com
Adolf Würth GmbH & Co. KG · 74650 Künzelsau · T +49 7940 15-0 · F +49 7940 15-1000 · www.wuerth.de · info@wuerth.com
PASSION FOR WORK
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