Discovering a crack in your bowling ball is a genuinely deflating experience, especially if it happens to a ball you've invested in and relied on. Cracks range from superficial surface marks that barely affect performance to structural fractures that render the ball unusable — and telling them apart matters both for your game and your wallet.
This guide explains why bowling balls crack, what you can do about different types of cracks, and how to make the most informed decision about whether to repair or replace.
Why Bowling Balls Crack
Temperature changes are the most common cause. Bowling ball coverstocks expand and contract with temperature. Leaving a ball in a hot car trunk in summer or a cold garage in winter exposes it to temperature extremes that the material wasn't designed for. The coverstock and core expand and contract at different rates, creating internal stress that can eventually fracture the surface. This is the single most preventable cause of cracking.
Impact damage — dropping the ball on a hard surface, bouncing it too hard on the lane approach, or other physical impacts — can cause cracks, particularly in areas already weakened by age or previous stress.
Material fatigue over time is real but often overstated. A well-cared-for bowling ball should last many years of regular use without cracking purely from age. However, reactive resin covers do become more brittle as the reactive components are used up, making older balls more susceptible to cracking from impacts and temperature swings.
Over-aggressive surface work — particularly using heat (from an oven or hot water) to draw oil out of a reactive cover — can cause cracking if done improperly. This procedure should only be performed by a knowledgeable pro shop operator who knows the safe temperature limits for specific ball materials.
Manufacturing defects occasionally exist. If a ball you bought new cracks without apparent cause within the first year or two of normal use, contact the manufacturer — most major brands (Brunswick, Storm, Hammer, Motiv) offer warranty coverage for manufacturing defects.
Types of Cracks and What They Mean
Hairline surface cracks: Very thin, shallow marks on the coverstock surface. Often don't penetrate into the ball material significantly. If the crack doesn't catch your fingernail when you run it across the surface, it may be cosmetic only. A pro shop can evaluate whether it affects structural integrity.
Surface cracks with depth: Cracks that you can feel with your fingernail — they have real depth in the coverstock. These affect ball performance because the crack changes the ball's surface texture unevenly, affecting how friction is applied across the coverstock during its journey down the lane. They're also potential weak points for further cracking.
Through-cracks (structural cracks): Cracks that penetrate into the core material or through the full ball structure. These are serious. A ball with a structural crack is not safe to use — it could shatter during delivery, potentially injuring you or damaging the lane. USBC rules also prohibit using a cracked ball in sanctioned competition.
Can a Cracked Bowling Ball Be Repaired?
Honest answer: minor surface cracks can sometimes be addressed, but no repair restores a cracked bowling ball to its original condition or makes a structurally compromised ball safe to use.
Some pro shops will fill very shallow surface cracks with a compatible filler material and resurface the ball, which can restore smooth surface contact and slow further propagation. This is a cosmetic and minor performance fix, not a structural repair. For a ball that still has good internal integrity and minor surface damage, this can be worthwhile — especially if the ball has a layout and drilling you want to preserve.
Structural cracks cannot be repaired in any meaningful sense. The ball should be retired.
USBC Rules on Cracked Balls
USBC Rule 15 prohibits using a ball with cracks, holes, or indentations (other than legal grip holes) in sanctioned competition. A cracked ball presented in league or tournament play will be deemed illegal, and the player required to switch to a legal ball. Any scores made with the illegal ball may be subject to revision depending on when the crack is discovered.
Preventing Bowling Ball Cracks
- Temperature control: Never leave your ball in a car trunk, especially in summer or winter. Store it at room temperature — the range your ball is designed for is roughly 40°F to 100°F, but consistent room temperature is ideal.
- Ball bag: Always transport your ball in a proper bowling bag. This protects it from impacts during transit and provides some thermal insulation.
- Proper cleaning: Use ball cleaners approved for your coverstock type. Harsh chemicals can degrade the coverstock material over time, making it more brittle.
- Avoid excessive heat treatments at home: The "oven method" for oil extraction is risky. Have it done professionally or use proper oil-removing machines available at many pro shops.
If your ball cracks under warranty: Document the crack with photos and contact the manufacturer directly. Major brands take warranty claims seriously and will often replace a ball that cracked due to a manufacturing defect within a reasonable timeframe.