How to Choose Skateboard Wheels A Comprehensive Guide

How to choose skateboard wheels is a fundamental question for any skater, from the novice to the seasoned pro. The wheels are your direct connection to the ground, influencing everything from your speed and grip to your ability to perform tricks. Selecting the right wheels can drastically improve your skating experience, making it smoother, more responsive, and more enjoyable. We’ll delve into the key factors to consider, providing you with the knowledge to make informed decisions and find the perfect wheels for your style and terrain.

This exclusive guide breaks down the complexities of wheel selection, examining diameter, hardness, shape, material, and how these elements interact with your riding style and the surfaces you skate. We will explore the nuances of each aspect, providing practical examples and expert insights to help you navigate the diverse world of skateboard wheels.

Wheel Diameter

Choosing the right skateboard wheel diameter is crucial for your riding experience. It directly impacts your board’s performance, influencing factors like speed, maneuverability, and the types of terrain you can comfortably skate on. Understanding how wheel diameter works will help you select wheels that best suit your skating style and preferred environments.

How Wheel Diameter Affects Skateboarding Performance

The diameter of your skateboard wheels significantly affects several aspects of your ride. Larger wheels generally roll faster and maintain their speed better, while smaller wheels offer greater maneuverability and are often preferred for technical street skating. The diameter impacts both your ability to roll over obstacles and the overall feel of your board.

Wheel Diameter Examples and Typical Uses

Different wheel diameters cater to various skating styles and terrain types. Consider these examples:

• 50-53mm: These are typically used for street skating and technical tricks. They’re smaller, lighter, and allow for quicker response times, making them ideal for flip tricks and navigating tight spaces.
• 54-56mm: This is a versatile size, suitable for both street and park skating. They offer a good balance of speed and maneuverability, allowing for a broader range of skating styles.
• 56-60mm: These wheels are commonly used for cruising, bowl riding, and vert skating. They provide increased speed, better roll over rough surfaces, and more stability.
• 60mm+: These are often found on longboards and cruisers. They provide the highest speeds and are designed to handle rougher terrain with ease.

Advantages and Disadvantages of Smaller vs. Larger Wheels

The choice between smaller and larger wheels involves trade-offs. Each size offers unique advantages and disadvantages, influencing your overall skating experience.

• Smaller Wheels:
  • Advantages: Lighter weight, faster acceleration, greater maneuverability, lower center of gravity, and easier for technical tricks.
  • Disadvantages: Slower top speed, less roll over rough surfaces, and more susceptible to getting caught on cracks or pebbles.
• Larger Wheels:
  • Advantages: Higher top speed, better roll over rough surfaces, more stability, and smoother ride.
  • Disadvantages: Heavier, slower acceleration, less maneuverable, and can be more difficult for technical tricks.

Wheel Diameter and Terrain Suitability, How to choose skateboard wheels

The following table summarizes how wheel diameter impacts suitability for different terrains. The information is based on common practices and preferences among skateboarders, but personal preference always plays a role.

Wheel Hardness (Durometer)

Understanding wheel hardness is crucial for selecting the right skateboard wheels. The hardness of a wheel, measured using the Shore durometer scale, significantly impacts a skateboard’s performance. This section will delve into the Shore durometer scale, explaining the differences between soft and hard wheels and how wheel hardness affects your skateboarding experience.

The Shore Durometer Scale

The Shore durometer scale measures the hardness of rubber and other polymers, including skateboard wheel urethane. It is a standardized scale used to determine the resistance of a material to indentation. The scale is divided into two main categories: Shore A and Shore D. Skateboard wheels primarily use the Shore A scale. The Shore A scale ranges from 0A (very soft) to 100A (very hard).

Some wheels use a B scale, but that is less common.

Differences Between Soft and Hard Wheels

The primary difference between soft and hard wheels lies in their urethane composition and resulting hardness. Soft wheels, with lower durometer readings (typically 78A-87A), are more pliable and offer more grip. Hard wheels, with higher durometer readings (typically 99A-101A+), are less flexible and roll faster.

How Wheel Hardness Impacts Grip, Speed, and Ride Feel

Wheel hardness profoundly affects several aspects of skateboarding performance. The durometer rating directly influences grip, speed, and overall ride feel.

• Grip: Softer wheels provide more grip because they deform more easily, conforming to the surface and increasing contact area. Harder wheels offer less grip, allowing for easier sliding and more speed.
• Speed: Harder wheels roll faster on smooth surfaces due to less friction. Softer wheels, while providing more grip, can slow you down on smooth surfaces due to increased friction.
• Ride Feel: Softer wheels absorb more vibrations and provide a smoother ride, especially on rough surfaces. Harder wheels transmit more vibrations, resulting in a harsher ride.

Ideal Wheel Hardness for Different Skateboarding Styles

Choosing the right wheel hardness depends on the type of skateboarding you do.

• Street: For street skating, where smooth surfaces are often encountered, harder wheels (99A-101A+) are typically preferred. These wheels offer speed and allow for easier sliding on rails and ledges. They are also durable.
• Park: Park skating often involves a mix of smooth transitions and rougher surfaces. Wheels in the range of 95A-101A are commonly used. This range provides a balance of speed, grip, and durability. Some skaters may opt for softer wheels (88A-95A) for extra grip on transitions.
• Cruising: Cruising typically involves riding on various surfaces, including rougher roads. Softer wheels (78A-87A) are ideal for cruising. These wheels absorb bumps and cracks, providing a smoother and more comfortable ride. They also offer excellent grip for turning and navigating uneven terrain.

Wheel Shape and Profile: Edge Design

The shape of your skateboard wheels significantly impacts your riding experience. Different profiles influence how your board slides, grips, and maintains stability. Understanding these nuances allows you to choose wheels that best suit your skating style and terrain.

Wheel Shape Influence on Performance

The edge design, or profile, of a skateboard wheel dictates how it interacts with the ground. This interaction determines crucial aspects of performance like sliding, grip, and stability. Consider the intended use of your skateboard; the shape of the wheel should complement your style.

Choosing skateboard wheels involves considering durometer (hardness) and size, impacting ride feel and performance. Similar to how you might research vehicle drivetrains, understanding wheel characteristics is key. Just as one might ask does the rav4 have all wheel drive to understand its capabilities, selecting skateboard wheels requires evaluating terrain and desired maneuverability for optimal skateboarding.

Wheel Shape: Conical, Full, and Round

The primary wheel shapes include conical, full, and round. Each shape offers unique advantages and disadvantages. These shapes impact the rolling characteristics and how the wheel responds to various riding conditions.

• Conical Wheels: These wheels feature a tapered or beveled edge. They are versatile, offering a balance of grip and slide. The conical shape provides a responsive feel for tricks and slides. The bevel allows for a smoother transition onto rails and ledges. These are often preferred by street skaters.

• Full Wheels: Full wheels have a rounded edge, providing maximum grip and stability. They excel on rough surfaces and in situations where a strong grip is essential. These are suitable for cruising, bowl riding, and maintaining speed on uneven terrain. The full profile resists sliding and offers excellent control.
• Round Wheels: Round wheels have a completely rounded edge, maximizing slide potential. They are ideal for advanced skaters who prioritize sliding and technical tricks. The rounded profile reduces friction, making it easier to initiate and control slides. However, they may offer less grip than other shapes, particularly on rough surfaces.

Wheel Material: Urethane Composition: How To Choose Skateboard Wheels

The material of your skateboard wheels is paramount to your riding experience. While shape, size, and hardness are crucial, the urethane compound itself dictates the wheel’s grip, roll speed, and overall durability. Understanding the nuances of urethane composition allows you to select wheels perfectly suited to your skating style and the surfaces you typically ride. This material is the heart and soul of a skateboard wheel, directly influencing how it performs.

Urethane’s Role in Skateboard Wheels

Urethane is a type of polymer that’s ideally suited for skateboard wheels because of its unique properties. It provides a balance of grip, rebound (the wheel’s ability to spring back after impact), and abrasion resistance. The specific chemical formula of the urethane dictates these characteristics. The composition, including the ratio of the ingredients, the manufacturing process, and the additives used, all contribute to the final performance of the wheel.

Different urethane formulas are developed for various riding styles, from street skating to cruising.

Urethane Formulas and Performance Effects

Different urethane formulas create distinct wheel behaviors. The variations in formulas influence several key performance aspects.Here’s a breakdown of how different urethane compounds impact wheel performance:

• Grip: Softer urethanes, generally with lower durometer ratings, offer more grip. This is beneficial for street skating, where precise control and sticking to surfaces are essential. Harder urethanes provide less grip, leading to a looser feel, favored by some skaters for sliding and speed.
• Roll Speed: Harder urethanes typically roll faster due to reduced friction. This is especially noticeable on smooth surfaces like skate parks and well-maintained streets. Softer urethanes, while grippier, can slow you down slightly due to increased friction.
• Rebound: Higher rebound means the wheel returns to its original shape quickly after impact, leading to a more responsive ride and better energy transfer. Some urethanes are formulated for high rebound, making them ideal for tricks and fast skating. Lower rebound wheels absorb more impact, offering a smoother ride on rough surfaces.
• Wear Resistance: The durability of a wheel is directly related to its urethane compound. Harder urethanes tend to last longer, as they resist abrasion better. Softer wheels wear down faster, especially when subjected to aggressive skating and sliding.
• Flatspot Resistance: Flatspots occur when the wheel’s surface deforms due to prolonged sliding or impact. Urethane formulas play a significant role in minimizing flatspots. Urethane blends that balance grip and hardness are less prone to developing them.
• Surface Feel: The feel of the wheel on the riding surface varies significantly depending on the urethane. Softer wheels absorb more vibrations, providing a smoother ride on rough surfaces. Harder wheels transmit more of the surface feel, offering a more direct connection to the ground.

Urethane Compound Effects on Wheel Durability and Wear

The urethane compound directly influences how quickly a wheel wears down.The following factors determine wheel durability:

• Hardness: As mentioned previously, harder wheels generally last longer. The increased resistance to abrasion means the wheel material takes longer to wear away.
• Riding Style: Aggressive street skating, including slides, grinds, and power slides, significantly increases wear. Cruising or riding on smooth surfaces reduces wear.
• Surface Type: Rough surfaces, such as asphalt with a lot of aggregate, cause wheels to wear down faster than smooth surfaces, like concrete.
• Urethane Formula: Some urethane formulas are specifically designed for enhanced durability. These compounds often incorporate additives to improve abrasion resistance.
• Wheel Shape and Profile: Wheel shapes with a wider riding surface may distribute wear more evenly, potentially extending the wheel’s lifespan.

Terrain Considerations: Where Will You Skate?

The surface you plan to ride on is perhaps the single most important factor in choosing the right skateboard wheels. Different terrains demand different wheel characteristics to provide the best performance, control, and ride quality. Selecting wheels that match your preferred skating environment will significantly impact your overall experience, allowing you to maximize fun and progress.

Wheel Selection Based on Terrain

The best skateboard wheel choice is directly related to the surface you intend to skate. Whether you’re hitting the streets, carving bowls at the skatepark, or cruising over rough asphalt, your wheel selection will dictate your control, speed, and comfort.

• Street Skating: Street skating typically involves skating on smooth surfaces like concrete, asphalt, and ledges.
• Park Skating: Skateparks offer a variety of features, including ramps, bowls, and transitions, usually made of concrete or wood.
• Rough Ground/Cruising: Cruising and skating on rough ground requires wheels that can absorb vibrations and handle uneven surfaces.
• Vert Skating: Vert skating takes place on large, vertical ramps, demanding wheels that provide speed and stability.

Factors for Terrain-Specific Wheel Choices

Understanding the key factors that influence wheel performance on different terrains allows for informed decisions. These factors include the surface’s smoothness, the presence of obstacles, the desired speed, and the need for maneuverability.

• Surface Smoothness: Smooth surfaces allow for harder wheels and faster speeds, while rough surfaces require softer wheels for shock absorption.
• Obstacles: The presence of cracks, pebbles, or gaps necessitates wheels that can roll over them without getting stuck or causing instability.
• Desired Speed: Harder wheels generally provide faster speeds, whereas softer wheels may offer a slower but more controlled ride.
• Maneuverability: Wheel shape and size affect how easily you can turn and control your board.

Terrain-Based Wheel Recommendations

The following table provides a comparison of wheel recommendations based on different terrain types, offering guidance on diameter, hardness, and shape for optimal performance.

Brand and Quality: Choosing Reputable Brands

Choosing the right skateboard wheels is a crucial part of the skateboarding experience, and the brand you choose significantly impacts the overall performance and durability of your setup. Investing in wheels from well-regarded brands often means investing in quality, performance, and a product that’s been tested and refined over time. These brands understand the nuances of wheel design, material science, and the demands of various skateboarding styles.

Importance of Choosing Wheels from Reputable Brands

Reputable brands have built their reputations on consistent quality, innovative designs, and a commitment to serving the skateboarding community. They often invest heavily in research and development, resulting in wheels that offer superior performance, durability, and a smoother ride. Choosing a well-known brand also means you’re more likely to find replacement wheels easily and benefit from the brand’s experience and expertise.

Examples of Well-Regarded Skateboard Wheel Brands

Several brands have established themselves as leaders in the skateboard wheel industry. These brands are known for their quality, innovation, and contributions to the sport.

• Bones Wheels: Bones is widely respected for its high-quality urethane and consistent performance. They offer a wide range of wheels for various terrains and skating styles.
• Spitfire Wheels: Spitfire is a very popular choice among skaters, known for their durable wheels and various shapes and sizes. They are particularly well-regarded for their Formula Four urethane.
• Ricta Wheels: Ricta is recognized for its innovative designs and high-quality urethane formulas, providing excellent performance and durability. They offer a range of wheels suited for street and park skating.
• OJ Wheels: OJ is another well-known brand with a strong presence in the skate community, offering a variety of wheels designed for different terrains and skating styles.
• Powell Peralta: Powell Peralta, a legendary name in skateboarding, produces wheels known for their durability and performance.

Evaluating the Quality of Skateboard Wheels

Evaluating the quality of skateboard wheels involves considering several key factors that contribute to their overall performance and longevity. High-quality wheels will generally offer a smoother ride, better grip, and greater resistance to wear and tear. They are also less likely to flat spot.

Key Elements that Define High-Quality Wheels

High-quality skateboard wheels are characterized by several key features that contribute to their performance and durability. These elements help skaters enjoy a better riding experience and get more value for their money.

• Urethane Formula: The specific urethane formula is critical. Premium urethanes provide a balance of grip, rebound, and durability. Some brands have proprietary formulas that are highly regarded.
• Shape and Profile: The shape and profile of the wheel impact its performance. A well-designed shape provides optimal grip, roll speed, and resistance to flat spots.
• Durability: High-quality wheels are designed to withstand the wear and tear of skateboarding, including impacts, abrasion, and flat spots. Look for wheels known for their longevity.
• Consistency: Consistent manufacturing processes ensure that all wheels in a set perform similarly. This provides a balanced and predictable ride.
• Core Material (if applicable): Some wheels feature a core. The core material and design can influence the wheel’s performance, providing stability and support.
• Brand Reputation: Brands with a strong reputation for quality and innovation often produce wheels that meet higher standards.

Budget Considerations

Choosing skateboard wheels involves balancing your needs with your wallet. Understanding how budget influences your wheel selection is crucial for making informed decisions. Price often reflects the materials, manufacturing processes, and brand reputation, directly impacting the wheel’s performance and longevity.

Wheel Price Ranges and Performance

The price of skateboard wheels can vary significantly. This range often dictates the quality of the urethane, the precision of the manufacturing, and the overall durability. Here’s a breakdown of different price points and their associated performance characteristics.
Here is a table comparing wheel price ranges and expected performance characteristics.

Consider the following when selecting wheels within your budget:

• Prioritize Your Needs: Determine your primary skating style (street, park, cruising) and choose wheels that suit that environment.
• Research Brands: Read reviews and compare different brands and models within your budget.
• Don’t Always Choose the Cheapest Option: While saving money is important, sacrificing quality can lead to a less enjoyable skating experience and require more frequent replacements.
• Consider Sales and Promotions: Look for deals and discounts to get the best value for your money.

Riding Style: Matching Wheels to Your Style

Your riding style is the cornerstone of wheel selection. Different styles demand different wheel characteristics, and understanding this relationship is crucial for maximizing your performance and enjoyment on a skateboard. Choosing the right wheels based on how you skate will significantly impact your ability to execute tricks, cruise comfortably, and navigate various terrains.

Street Skating Wheel Recommendations

Street skating focuses on technical tricks performed on obstacles like rails, ledges, stairs, and flat ground. The primary objective is precision, control, and responsiveness.

• Wheel Diameter: Smaller diameters (48mm-54mm) are generally preferred. Smaller wheels are lighter, allowing for quicker acceleration and easier maneuverability for flip tricks and technical maneuvers. They also sit lower to the ground, improving board feel and reducing the risk of wheel bite.
• Wheel Hardness (Durometer): Harder wheels (99A-101A) are the standard. This hardness provides excellent slide control, allowing skaters to lock into grinds and slides more effectively. Harder wheels also offer better responsiveness on impact.
• Wheel Shape and Profile: Wheels with a conical or rounded profile are common. These profiles offer a balance of grip and slide control, allowing for smooth transitions between rolling and sliding.
• Wheel Material: High-rebound urethane is desirable. This type of urethane provides a good balance between grip and slide, allowing for consistent performance across various street obstacles.

Cruising Wheel Recommendations

Cruising prioritizes smooth rides, comfortable navigation, and covering distance. The focus is on a relaxed and enjoyable experience.

• Wheel Diameter: Larger diameters (54mm-60mm+) are often used. Larger wheels roll faster, maintain speed more easily, and absorb vibrations from rough surfaces.
• Wheel Hardness (Durometer): Softer wheels (78A-90A) are ideal. Softer wheels provide a smoother ride by absorbing impacts and vibrations, making them perfect for cruising on less-than-perfect surfaces.
• Wheel Shape and Profile: Rounded or conical profiles are suitable. These profiles offer a good balance of grip and roll, making them easy to maneuver.
• Wheel Material: Urethane with good rebound and durability is important. This ensures longevity and consistent performance over varied terrains.

Vert Skating Wheel Recommendations

Vert skating involves riding in a halfpipe or vertical ramp. The focus is on speed, airtime, and maintaining control during transitions.

• Wheel Diameter: Medium diameters (52mm-56mm) are a good starting point. This size offers a balance of speed and maneuverability needed for transitions and air tricks.
• Wheel Hardness (Durometer): Harder wheels (97A-101A) are often preferred. The harder wheels provide the necessary grip for the transitions and control at high speeds.
• Wheel Shape and Profile: A wider wheel profile, either conical or square, provides stability and grip during transitions. This helps prevent slipping during landings.
• Wheel Material: Urethane with high rebound is critical. This characteristic allows for quick acceleration and responsiveness during transitions.

Park Skating Wheel Recommendations

Park skating combines elements of street and vert skating, incorporating both street obstacles and transition features. The ideal wheel setup often reflects a compromise between these two styles.

• Wheel Diameter: A versatile range, often between 52mm and 56mm. This allows for both technical street tricks and riding transitions.
• Wheel Hardness (Durometer): A hardness between 97A and 101A is typical. This offers a balance of grip for transitions and slide control for street obstacles.
• Wheel Shape and Profile: Wheels with a slightly rounded or conical profile are often preferred, offering a good balance of grip and slide.
• Wheel Material: High-rebound urethane provides a good balance between grip, slide, and durability.

Freestyle Skating Wheel Recommendations

Freestyle skating emphasizes technical flatground tricks and creative maneuvers. Wheel selection prioritizes control and responsiveness.

• Wheel Diameter: Smaller diameters (48mm-52mm) are common. Smaller wheels contribute to a lower center of gravity and increased maneuverability.
• Wheel Hardness (Durometer): Hard wheels (99A-101A) are typically used. This allows for excellent slide control, which is essential for many freestyle tricks.
• Wheel Shape and Profile: Wheels with a slightly conical or rounded profile offer a good balance of grip and slide control.
• Wheel Material: High-rebound urethane is crucial. This helps with the responsiveness and consistency required for complex flatground maneuvers.

Wheel Maintenance and Care

Keeping your skateboard wheels in top condition is crucial for a smooth ride and to maximize their lifespan. Regular maintenance not only enhances performance but also saves you money by preventing premature wear and tear. Proper care involves simple practices that, when consistently applied, can significantly extend the time before you need to replace your wheels.

Extending Wheel Lifespan Through Maintenance

The lifespan of your skateboard wheels is directly related to how well you care for them. Neglecting maintenance can lead to uneven wear, flat spots, and reduced rolling efficiency. By adopting a proactive approach, you can ensure your wheels perform optimally for a longer duration.

Proper Wheel Care Practices

Implementing these practices will keep your wheels rolling smoothly and efficiently:

• Regular Inspection: Inspect your wheels before and after each skate session. Look for any signs of damage, such as cracks, chunks missing, or flat spots. Early detection allows for timely intervention.
• Wheel Rotation: Just like car tires, rotating your skateboard wheels can help distribute wear evenly. Rotate them regularly, perhaps every few weeks or months, depending on how often you skate. This is especially important if you primarily skate in one direction or do a lot of the same tricks.
• Bearing Maintenance: Bearings are a critical component of wheel performance. Clean and lubricate your bearings regularly. Dirt and grime can accumulate inside the bearings, hindering their rotation and accelerating wheel wear. Use a bearing cleaner and lubricant designed for skateboards.
• Tightening Trucks: Make sure your trucks are tightened appropriately. Trucks that are too loose can cause wheels to rub against the deck, leading to uneven wear. However, avoid over-tightening, as this can restrict wheel movement and make the ride less responsive.
• Storage: Store your skateboard in a cool, dry place away from direct sunlight and extreme temperatures. These conditions can degrade the urethane of the wheels over time.

Common Wheel Wear Patterns and Addressing Them

Understanding the different ways your wheels wear can help you diagnose and address potential issues.

• Flat Spots: Flat spots are often caused by sliding or locking up your wheels. These can significantly impact your ride quality. The best way to address flat spots is to avoid the actions that cause them. Practicing controlled sliding and avoiding excessive locking can prevent flat spots from forming.
• Uneven Wear: Uneven wear can result from various factors, including skating primarily on one side, performing the same tricks repeatedly, or not rotating your wheels. Rotating your wheels regularly helps distribute wear more evenly.
• Chunking: Chunking refers to pieces of the urethane breaking off. This is more common with softer wheels and can be caused by impacts, rough surfaces, or aggressive skating styles. Choosing the right wheel hardness for your terrain and skating style can help minimize chunking.
• Coning: Coning happens when the wheel wears down more on one side than the other, resulting in a cone-like shape. This can be caused by leaning heavily on one side of your board or performing certain tricks repeatedly. Regular wheel rotation can help prevent coning.

To clean and maintain your wheels, follow these steps:

1. Remove the Wheels: Detach the wheels from your skateboard trucks.
2. Clean the Wheels: Wipe down the wheels with a clean cloth to remove any surface dirt and debris.
3. Clean the Bearings: Remove the bearings from the wheels (if necessary). Use a bearing cleaner and follow the instructions on the product. Remove dirt and grime from the bearings.
4. Lubricate the Bearings: Apply a few drops of bearing lubricant to each bearing. Spin the bearings to ensure the lubricant is evenly distributed.
5. Reassemble: Reassemble the wheels and bearings, ensuring the bearings are properly seated in the wheels.
6. Reinstall the Wheels: Put the wheels back on your trucks.

Last Word

In conclusion, selecting the ideal skateboard wheels is a personalized journey. Understanding the interplay of diameter, hardness, shape, and material allows you to tailor your setup to your specific needs. Whether you’re cruising the streets, shredding the park, or tackling rough terrain, the right wheels can significantly enhance your performance and enjoyment. Remember to consider your riding style, budget, and the quality of the brand when making your final decision.

With the right knowledge and a bit of experimentation, you’ll be well on your way to rolling smoothly and confidently.

FAQ Section

What’s the difference between a conical and a full wheel shape?

Conical wheels have a beveled edge, offering more slide control and are favored for technical street skating. Full wheels have a rounded edge, providing more grip and stability, suitable for cruising and transition skating.

How often should I rotate my skateboard wheels?

Rotating your wheels every few sessions or when you notice uneven wear can help extend their lifespan and ensure consistent performance. This involves swapping wheels between positions on your board.

Can I use different hardness wheels on the same board?

Yes, but it’s generally not recommended unless you have a specific reason. Mixing hardnesses can create an uneven ride and affect your board’s handling. It’s best to keep all four wheels with the same durometer.

What’s the best way to clean my skateboard wheels?

Use a soft cloth and warm, soapy water to wipe away dirt and grime. Avoid harsh chemicals or abrasive cleaners that can damage the urethane. Be sure to dry the wheels thoroughly before riding.

How do I know when to replace my skateboard wheels?

Replace your wheels when they become significantly worn down, have flat spots, or start to chunk. Also, if they’re no longer providing the grip or performance you need, it’s time for a new set.