Measuring tire tread - Determine tread depth without measuring device
- Construction - car tires
- Prerequisite for a good grip
- Consequences of too low tire tread
- Measure tread depth
- Buy used tires "> Tips for quick readers
The tires are the contact points to the road. All four tires together only give an area of about one DIN A4 sheet, with which a heavy car touches the ground. Tires are therefore faced with special challenges that can not be compromised. Find out in this text everything about how you can check your tires even without a measuring device.
Construction - car tires
To understand how important the depth of the tire tread is, look inside the tire once.
The tires of vehicles are made of a composite material. Inside they have a braid of steel wires, the so-called "carcass". This keeps the tire together and makes it so highly resilient. The steel mesh is covered with a layer of rubber. A damaged carcass is recognizable by bumps and blisters in the flank. The rubber keeps the tire air and waterproof. It also protects the steel mesh against rust. The rubber is quite thin on the flanks of the tires, as it only has to fulfill this sealing function. On the inside, however, it is much thicker. Here the transmission of the movement takes place.
The contact with the asphalt of the road causes a warming and a permanent abrasion of the tires. So that the tire always has enough friction, in technical language called "grip", to the road, it is equipped with a profile. The profile enlarges the surface of the tire. Under the pressure of the weight of the car, the tire slightly expands. This allows the inside flanks of the profile to also affect the ground and improve adhesion.
Prerequisite for a good grip
For optimal grip, four conditions must be met:
- Tires matching the vehicle
- Enough plasticizer in the gum
- Correct air pressure in the wheel
- Sufficient tread depth on the tire
The tires must fit the vehicle, the application and the season. High-performance sports cars are usually not optimally equipped with standard tires or retreaded tires. For tractors there are tires for farming and for road driving. After all, summer tires should never be driven in winter. Conversely, it is also not optimal, but allowed.
The plasticizer in the rubber degasses with time. Above all, warming makes the rubber hard and brittle. Therefore, tires have only a limited durability. At least every five years, they should be replaced, otherwise threatens a loss of control while driving. This usually leads to accidents. Too hard tires are quickly noticed while driving. The car drives uncertainly and the tires start to squeak in every curve. Then at the latest the age of the tires should be checked. Just look at the tires: the four-digit DOT number tells you how old the tire is. The number code 1914 means "19. Calendar week 2014 "
The air pressure determines how full the tire is filled. Excessive air pressure reduces the bearing surface of the tire. This reduces the grip again. In addition, tires that are filled far beyond the limit can burst suddenly when heated. Too low tire pressure makes the car "swim". It drives very uncertainly and reluctantly through the curves. The correct tire pressure is usually noted on one of the door frames or on the inside of the tank cap. Modern vehicles from year of construction 2014 must have a tire pressure control system. For this purpose, the rims must be equipped with pressure sensors. Care must be taken to ensure this detail when buying accessories rims, otherwise the operating permit of the car expires. Too little tire pressure increases wear on the tread and on the carcass.
The tread pattern is crucial to the function of the wheel. A worn-out tire drives very unsafe. A bare rolling surface is no longer safe. Legally prescribed is a minimum depth of 1.6 millimeters. However, the ADAC recommends a minimum depth of 3 millimeters for summer tires and a minimum tread depth of 4 millimeters for winter tires.
Consequences of too low tire tread
Tires with too low a profile cause unsafe handling. This is expressed by an extended braking distance and the car comes easily into skidding. Old tires can also burst easily. Who gets caught with worn tires pays 60 euros fine and gets a point in the central register. In accidents where worn tires are detected, the road user usually has a complicity. In addition, you endanger your insurance coverage with a non-traffic-safe car.
Measure tread depth
There are several ways to determine the minimum depth of the profile even without profile depth gauge.
The fastest and easiest option is the one euro piece. The bronze-colored edge of the one-euro coin is exactly 3 millimeters wide. The coin is simply put in the middle of the profile. If the bronze edge disappears in the tire tread, the minimum depth is reached. If he remains visible edge, should be checked more closely.
The tire tread has also incorporated a "last warning". These are small transverse webs which indicate the absolute minimum of the tread depth. If the tire has traveled so far that the webs merge into the tire profile, it must be replaced immediately.
A normal Zolllstock can also serve as a profile depth gauge. It is not quite as accurate as the professional gauges, but it is sufficient for the approximate assessment. Tip: Always sell a tire with an image showing the depth of the tire tread. This creates trust and ensures transparency and clarity.
Examine the tires carefully
When measuring the tread depth, the whole tire should be examined closely. Typical indicators for a tire change are:
- Bumps and blisters on the flank
- Cracks and porous spots in the tire
- Unilaterally worn tires
- "Brake disks"
Bumps and blisters on the flank indicate a damaged carcass. The steel mesh is broken and can no longer hold the pressure. Then the air pressure presses against the flank and makes it bulge.
Cracks and porous areas are caused by too low tire pressure and aging of the tires. If the rubber weakens, it can no longer make the tightness. Water can penetrate and rust the carcass.
One-sided worn tires indicate a fault on the chassis. Mostly the track is blocked. This can happen through normal wear. Mostly, however, something is defective in the steering mechanism. Typical damage is worn out wishbones, defective shock absorbers or insufficient tire pressure.
The brake plates are created on vehicles that make a full braking from high speed while blocking the wheels. This phenomenon occurs only rarely in the widespread use of ABS systems. Nevertheless, an older tire should also be examined. A brake plate usually also results in internal damage.
Buy used tires "> Tips for quick readers
- A one-euro coin is enough for the tire control
- Modern cars need tire-pressure sensors
- A tread depth gauge belongs in every car
- Always check the tires completely
- If the bridge is visible, the tire has worn down and must be replaced.
- Always check tires for foreign objects such as nails