Cupped tires are usually a sign of:
- Loose, worn, or bent shock absorbers/suspension parts.
- Tires that are not balanced or worn out.
- Wheels that are not aligned properly.
- Low-quality tires.
The most noticeable signs of cupped tires are a scalloped treadwear pattern and noise. It appears as though the tread has been sucked in small pieces, ranging from 3- to 4-inches across, along the edges, or in the middle. This is a result of the wheel bouncing, which means the tire doesn’t touch the surface evenly.
This is similar to a bad bearing. It’s important to be able to distinguish the sounds. As you accelerate, the noise from cupped tires will increase. The direction of the part will affect the wheel bearing noise. For example, if you hear the sound or changes in the sound when turning left, your driver’s side wheel bearing may need attention.
Main Reasons of Cupped Tires
Loose, Worn, Bent Shocks or Suspension Parts
Shock absorbers and the car’s suspension are the key elements that allow the car to ride smoothly. If any part of this system becomes bent or worn, the wheel will bounce. This can cause a bumpy ride.
Shock absorbers need to be changed every 50,000-60,000. Struts should be replaced every 60000-90,000. Suspension bushings last for 100,000-150,000 miles. To avoid clogged tires, inspect your suspension bushings at least once per year or every 12,000 miles.
Shocks are often ignored by drivers. Only about 1/5 of them believe that proper maintenance can improve handling. A survey done by a large shocks manufacturer revealed that 70% of drivers consider shocks to be a minor part of the car, responsible for ride comfort. But, the Cologne Institute for Traffic Safety in Switzerland proved the importance good shock absorbers. The research team found out that as the parts’ dampening ability descends to 50%, it takes a car 23% more distance to stop. For example, it’s about 21 feet at 31 mph, which is a long braking distance.
Cupped tires can also be caused by shocks. Problems with these parts aren’t as frequent, but make sure to check ball joints, bushings, springs, wheel bearings, etc. It could be any part that connects the wheel and the rest of your vehicle.
Tire Imbalance or Runout
Tire Imbalance
A tire is out of balance when the weight across its circumference is irregular. The principal consequence is vibration at 45 MPH, which increases with increasing speed. The tire may lose its grip of the road for a brief time as the wheel bounces. This bounce creates rubber scoops on the tire and causes cupped tires. This is also known patch wear. The scoops may not be as regular as those due to a failing suspension.
If tire imbalance is the only reason for tire cupping in your case, go to a tire shop to get your tires balanced. A technician will balance your tires by placing small weights in the opposite direction of the more rigid spots. If there aren’t any other problems, it will cost $10-15 per wheel. Find the most trusted tire shops right here.
An imbalance of even 0.25 ounces could cause cupped tires. This can lead to poor handling. Balancing your tires on time can extend the life of your tires by up to 20%. If you want to learn more about tire imbalance and possible solutions, read this article.
Tire Runout
Runout is a term that means not a perfectly round shape of a tire, wheel, or rim. There are two types:
- Lateral – side-to-side flaw that causes wobbling.
- Radial – imperfection between the high and low spots (or average line).
To some extent, runout is acceptable, but when the lateral increases to .08” and/or the radial increases to .06”, it becomes a problem. Tires that are constantly wobbling or shaking can cause tire to lose grip on the road and result in cupped tires.
Wheel Misalignment
Misaligned wheels are not perpendicular to the road and/or not parallel to each other. The alignment consists of three angles:
- Camber.Camber is the angle that places the wheels perpendicular to the road surface. Camber zero is the ideal setting. If it changes from negative to positive, tires can wear unevenly and suspension could fail prematurely.
- Caster.This angle determines the distance between the steering axis and the road. As caster zero is the best setting, it’s important to avoid a negative or positive angle that could make it hard to keep the vehicle straight and turn.
- Toe.Toe. It’s the most important for even tire wear as if the setting is in or out, rubber will be wearing more on one side, often leading to cupped tires.
Misalignment is often responsible for back tire cupping, especially if the rear and front tires aren’t parallel to each other. You should continue to inspect the suspension after the procedure has been completed. However, such checks are necessary every 6-12 months even if you don’t replace any of the suspension parts.
Low Quality Tires
Cheap tires of poor quality or fake tires will most probably cup with any minor vibration or bounce. They are also thinner and have less resistance to stress and temperature. These tires could be runout or heavily imbalanced, which can lead to premature cracking and premature aging.
If you somehow have such tires and notice premature cracking, cupped tire wear, or unnatural color of sidewalls, replace the tires as soon as possible. Make sure you choose new tires carefully and buy only from authorized dealerships or shops.
Identifying Cupped Tires
You can identify the issue and its possible reasons by:
- Noticing vibration and wobbly behavior, especially when hitting a road obstacle. Cupping means that at least one tire is leaking.
- You will notice that the vehicle is leaning too much to one side while turning. This indicates that the tires require balance.
- The car should be allowed to slow down on its own without needing to brake. A car that leans to one side will indicate imbalance.
- You can check for bouncing movements by pressing the car’s hood down. If the bounce does not stop, you may need to apply pressure again.
- Run your fingers along the tread to inspect the tires. While some cupping may not appear immediately, it can be felt by running your hands across the tread.
It is possible to save your suspension and tire, and improve comfort and safety by fixing it quickly.
Fixing the Issue
The best a driver can do to fix the issue is diagnose the tire-wheel assemblies and detect the cause of cupping. Take your vehicle to a shop for a check of your suspension, tires, and wheels. If a replacement is necessary, do it as soon as possible, including buying new tires if the specialist suggests doing so.
After all part replacements, ensure that you balance and rotate your tires. Rotation can help to smoothen uneven wear and prevent future irregularities. Balancing can help correct the tire’s weight distribution, since cupping could have affected it.
Align the wheels if suspension parts are damaged or need to be replaced.
Vehicle and Tire Maintenance to Prevent Cupping
The necessary procedures to avoid tire cupping are:
- Balancing.
- Rotating.
- Alignment of the wheels.
- Pressure check.
- Buy new tires at the right time.
It’s crucial to check tire balancing every 3,000-6,000 miles, as weight distribution within the tires changes as they wear. You should also rotate the tires every 5,000-8,000 miles to avoid uneven wear and prolong tire life. To prevent cupped tires and other problems, it is important to align the wheels. You should check the suspension condition every year and then have an alignment done if necessary.
Also, you should check tire pressure every month to make sure the inflation rate is stable and none of the tires loses more air than it should. Sometimes, severe underinflation can cause cupping in the middle.
It’s also important to remember that tires older than 5-6 years need full annual diagnosis. Also, tires that reach 2/32” depth, even if only in the scoops in the case of cupped wear, should be replaced. At that point they are considered dangerous, so don’t wait until they smooth out.
FAQ on Cupped Tires
Q: Can I Drive on Cupped Tires?
It’s acceptable to drive on them if the overall condition of the tires is good. Lower spots will wear more quickly than higher spots. This will eventually smooth them out. If the scoops are as deep as 2/32”, though, the tires are no longer fit for use. (2/32” is the legal minimum tread depth for tires.) You should not drive the tires if you decide to smoothen them out. This is especially true if the surface is wet.
Q: Why Is It Dangerous to Drive if I Have a Cupped Tire?
Because of the uneven contact between the surface and the tire, the tire can lose its grip. This could lead to control losses. It can also cause vibrations and noises that may damage other wheel parts, and even nausea to the driver and passengers.
Q: Why do my tires cup on the inside?
Tires that cup on the inside are caused by severe suspension problems. This is more common when the problem is due to bad wheel bearings, loose or damaged ball joints, or a damaged control arm, or steering linkage. To diagnose the suspension and all parts that link the wheel and the car, you will need to visit a repair shop.
Q: Why do my tires cup on the outside?
A damaged suspension could also be a possible cause if the wear is very close to the outside edge. If the wear is close to the outside edge, it could indicate a damaged suspension. Shock absorbers and struts could be responsible if there are hills or valleys.
Q: Why do my tires cup in the middle?
Common causes of middle cupping include severe underinflation or failure of shock absorbers or wheels bearings, tire balance, and damaged suspension. Underinflation-related cupping is rare and has noticeable characteristics. These scallops are more common and smaller than the shocks-related pattern, which has larger scoops. Damaged wheel bearings can cause deep, but small scallops.
Q: What causes my back tires to cup?
Bad wheel alignment causes back tires to scallop. If the tires are mounted on a truck, trailer or other vehicle, they may experience more pressure, which can cause the problem.
Maintenance is the Key to Avoiding Cupped Tires
When trying to avoid issues with tires, drivers usually put their efforts to maintaining the rubber. It is possible that the root cause of the problem lies in the vehicle. Neglecting to address it could lead to severe consequences. Some tire blowouts are caused by neglected tire scalloping, which is in turn caused by neglecting suspension, shocks, struts, etc.
Make sure to learn about the life expectancy of all parts connecting the wheels and vehicle. Find out what are the symptoms of a particular part’s failure and look for them when cupping occurs. You should pay enough attention to the basics of maintenance. If you do all that, tire cupping won’t be a problem for you.
