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THE WEIGHTBLOCK
A Bowling Balls Engine
The weightblock is the engine inside your ball. It shapes how energy is stored and released.
Toggle between Asymmetric and Symmetric weightblock cores
ASYMMETRIC
SYMMETRIC
CORE FUNDAMENTALS
Symmetrical vs Asymmetrical
“Predictable arc vs directional kick.”
- Sym = smoother, more predictable shape
- Asym = sharper, faster-responding motion
RG (Radius of Gyration)
“How fast the ball revs up.”
- Low RG = starts earlier.
- High RG = saves energy, pushes longer.
Differential
“How much potential the ball has to change direction.”
- High Differential = greater change of direction (bigger move).
- Low Differential = less change of direction (smoother, straighter).
Intermediate Differential (PSA)
“How fast it changes direction.”
- Higher int. diff = sharper/more defined move.
- Lower int. diff = transition is slower and smoother.
HOW RG & DIFFERENTIAL COMBOS COMPARE
See how common RG/Differential combinations translate to ball motion and lane use. Filter by brand to focus on Storm, Roto Grip, or 900 Global.
| RG / DIFF COMBO | REACTION TRAIT | BEST CONDITIONS | EXAMPLE BALLS |
|---|---|---|---|
| Low RG + High Diff |
Early & Strong
|
Heavy oil, fresh conditions | Roto Grip TNT, Storm Proton PhysiX, 900 Global Reality |
| High RG + Low Diff |
Clean & Smooth
|
Dry lanes, spares, late blocks | Storm Hy-Road Pearl, Roto Grip Hustle INK, 900 Global Burner Pearl |
| Mid RG + Mid Diff |
Benchmark / Balanced
|
Versatile, medium conditions | Storm !Q Tour, Roto Grip Helios, 900 Global Zen |
| Low RG + Low Diff |
Stable & Smooth
|
Short patterns, spare control | Storm Pitch Black, Fast Pitch |
| High RG + High Diff |
Angular & Delayed
|
Transition / needing shape downlane | Storm Dark Code, Roto Grip Rubicon UC3 |
SPI CORE LINEUP
Every core across Storm, Roto Grip, and 900 Global is engineered for a specific motion profile. Explore how each family differs in shape, energy retention, and best use cases.
LOW RG + HIGH DIFF
Designed for early revs, strong midlane traction, and stability in heavy oil.
Atomic™ A.I. Core
AsymmetricMax midlane read and continuation for heavy volumes.
Used in: Proton PhysiX, Summit Peak
Supercoil™ Core
AsymmetricCompact, dense engine for heavy roll and consistent traction.
Used in: DNA Coil, Super Nova
Sentinel™ Core
AsymmetricStrong asymmetry for control and continuation with big covers.
Used in: Virtual Energy Blackout
Element™ Max A.I. Core
AsymmetricHeavy-revving torque shape for strong backend motion.
Used in: DNA, DNA Coil
Solarion™ Core
AsymmetricHigh-flaring asymmetric A.I. structure for max hook potential.
Used in: Summit, Summit Peak
RST™ A.I. Core
AsymmetricResponsive asymmetry that creates angular yet controllable shape.
Used in: RST X-3, RST X-2 Pro
Momentous™ AV + A.I. Core
AsymmetricCompact asym core with strong midlane read and motion continuation.
Used in: Optimum Idol, Clone
Nucleus™ + A.I. Core
AsymmetricIconic shape blending predictability and backend strength.
Used in: Gem, Hyper Cell Fused
Defiant™ LRG Core
AsymmetricLarge radius of gyration for strong overall motion on oil.
Used in: Roto Grip Defiant, Hyper Cell
Rondure™ MaxD Core
AsymmetricHigh-diff shape producing heavy flare and downlane continuation.
Used in: Rubicon UC3, Rubicon UC2
Rocker™ + A.I. Core
AsymmetricCompact asymmetric block designed for a strong, sweeping backend motion that maintains energy through the pins.
Used in: Rubicon UC3, Rubicon UC2
Ellipse™ Asymmetric A.I. Core
AsymmetricAsymmetric A.I. block for defined breakpoint and strong backend.
Used in: Zen Gold Label
Disturbance™ Asymmetric A.I. Core
AsymmetricHigh energy asym for early traction and heavy midlane control.
Used in: Reality, Reality CheckHIGH RG + LOW DIFF
Promotes cleaner motion through the front part of the lane.
Surge™ Core
SymmetricHigher RG for easy length and smooth transitions.
Used in: Tropical Surge
Capacitor™ Core
SymmetricLow diff for urethane-like stability and spare control.
Used in: Pitch Black, Fast Pitch
Hustle™ Core
SymmetricSimple core design promoting consistent control and shape.
Used in: Hustle USA, Hustle RIPMID RG + MID DIFF
Balanced, benchmark shapes blending control and motion versatility.
ID™ A.I. Core
SymmetricClean fronts and responsive motion off the spot.
Used in: Phaze A.I., Fate
C³™ A.I. Core
SymmetricPredictable and readable shape for benchmark reactions.
Used in: IQ Tour 78/U A.I.
C³™ – Centripetal Control Core
SymmetricOriginal C³ variant offering smooth, balanced motion.
Used in: IQ Tour, IQ Tour Nano
Centripetal™ HD – A.I. Core
SymmetricHigh-density symmetric design providing strong midlane read with continuous backend motion for benchmark control.
Used in: !Q Tour 78/U A.I.
Shape-Lock™ HD Core
AsymmetricMidlane strength with angular finish for versatile ball motion.
Used in: Code Black, Code X
Ikon™ + A.I. Core
SymmetricSymmetric A.I. redesign for medium patterns with smooth backend.
Used in: Idol Cosmos, Tour Dynam-X
Wrecker™ + A.I. Core
SymmetricMid RG core offering controlled midlane and arcing finish.
Used in: Hustle RIP, MVP
Magna™ A.I. Core
SymmetricMedium differential shape offering clean motion and arc.
Used in: Harsh Reality
Meditate™ Symmetric A.I. Core
SymmetricBig symmetric A.I. core emphasizing continuous downlane motion.
Used in: Zen, Zen GoldLOW RG & LOW DIFF
Iconic or unique cores that define each brand’s identity and innovation.
Inverted Fe²™ A.I. Core
SymmetricModernized icon delivering signature Storm roll and control.
Used in: !Q Ruby, !Q 78/U
Inverted Fe² Technology™
SymmetricOriginal Thunder core known for timeless motion and feel.
Used in: Hy-Road, Hy-Road Pearl
Atmos™ A.I. Core
SymmetricClean and balanced roll with smooth continuation.
Used in: Summit Peak
3-Piece Core
SymmetricSimple design for straight-line stability and spares.
Used in: Mix, Ice Storm
Immersed™ Symmetric A.I. Core
SymmetricLarge symmetric core providing smooth, readable shape.
Used in: Zen Gold, Zen SoulHIGH RG & HIGH DIFF
Iconic or unique cores that define each brand’s identity and innovation.
Inverted Fe²™ A.I. Core
SymmetricModernized icon delivering signature Storm roll and control.
Used in: !Q Ruby, !Q 78/U
Inverted Fe² Technology™
SymmetricOriginal Thunder core known for timeless motion and feel.
Used in: Hy-Road, Hy-Road Pearl
Atmos™ A.I. Core
SymmetricClean and balanced roll with smooth continuation.
Used in: Summit Peak
3-Piece Core
SymmetricSimple design for straight-line stability and spares.
Used in: Mix, Ice Storm
Immersed™ Symmetric A.I. Core
SymmetricLarge symmetric core providing smooth, readable shape.
Used in: Zen Gold, Zen SoulWHY NUMBERS DONT TELL THE WHOLE STORY
Two balls. Similar specs. Totally different reactions. It all comes down to the coverstock.
EQUNOX
Strong Asym Torque
RG: 2.47
DIFF: 0.054
PSA: 0.016
COVERSTOCK: A1S Pearl Reactive
FACTORY FINISH: Power Edge
Even with a lower differential and intermediate differential (PSA) which would suggest less overall motion — the Equinox, because of the coverstock, produces more energy retention, which in turn creates more backend motion than the Physix Blackout.
- Hook Phase Timing: Late + Delayed
- Shape of Motion: Angular + Skid Flip
- Change of Direction: Immediate / Very Fast
- Roll Characteristic: Energy Retaining
PHYSICS BLACKOUT
Smooth & Blended Control
RG: 2.47
DIFF: 0.056
PSA: 0.018
COVERSTOCK: NEX Pearl Reactive
FACTORY FINISH: 2000 Grit
Even with a higher differential and intermediate differential (PSA) which would suggest more overall motion - the Physics blackout, because of the cover stock, produces more friction, which in turn creates a smoother hook motion than the Equinox.
- Hook Phase Timing: Mid Lane + Gradual
- Shape of Motion: Smooth + Round
- Change of Direction: Moderate / Medium
- Roll Characteristic: Continuous
Neither of these balls simply ‘hooks more.’ What defines their value is where they pick up and how they shape on the lane. Surface, layouts, and lane conditions can flip which one looks stronger — that’s why looking beyond the numbers is the real key to building an arsenal.
Toggle between the Equinox and the Physics Blackout and see how changing scenarios effect ball motion.
Select the scenario you would like to change to see the effect it has on ball motion
EQUNOX
Strong Asym Torque
ORIGINAL SURFACE – Power Edge
FACTORY SURFACE: Factory box finish with Power Edge polish.
WHY IT MATTERS: The polished surface minimizes early traction, helping the ball conserve energy for a stronger, sharper backend motion.
REACTION PROFILE: Clears the front part of the lane with ease, then makes a decisive, angular move
ARSENAL ROLE: Angular motion that thrives on heavier oil but still versatile with transition.
- Hook Phase Timing: Late + Delayed
- Shape of Motion: Angular + Skid Flip
- Change of Direction: Immediate / Very Fast
- Roll Characteristic: Energy Retaining
EQUNOX
Strong Asym Torque
SURFACE CHANGE – 2000 Grit
CHANGE MADE: Sanded from factory polish to 2000 grit
WHY IT MATTERS: Adds midlane traction while maintaining backend shape.
REACTION CHANGE: Reads friction sooner, smoothing out the breakpoint for a rounder, more predictable motion without losing energy retention.
ARSENAL IMPACT: Converts the Equinox into a benchmark control option that blends wet/dry transitions or sport-like friction zones.
- Hook Phase Timing: Midlane + Controlled
- Shape of Motion: Angular
- Change of Direction: Quick / Fast
- Roll Characteristic: Continuous
EQUNOX
Strong Asym Torque
SURFACE CHANGE – 1000 Grit
CHANGE MADE: Sanded from factory polish to 1000 grit
WHY IT MATTERS: Deepens traction window and increases total friction footprint in the oil.
REACTION CHANGE: Starts noticeably earlier in the midlane with a strong, continuous roll and a softer downlane move
ARSENAL IMPACT: Transforms the Equinox into a true heavy oil pearl specialist for early read and maximum control when polish or higher grits skate too long.
- Hook Phase Timing: Early
- Shape of Motion: Arc
- Change of Direction: Moderate / Medium
- Roll Characteristic: Continuous
EQUNOX
Strong Asym Torque
ORIGINAL LAYOUT – Standard Roll
LAYOUT: Standard/benchmark drilling (neutral pin-to-PAP distance, balanced CG/PSA).
WHY IT MATTERS: Provides a balanced transition from skid → hook → roll, without favoring earlier or later motion.
REACTION PROFILE: Medium length with a defined but controllable backend shape.
ARSENAL ROLE: Gives the ball its “intended” look and is a reference point for comparing stronger or weaker layout adjustments.
- Hook Phase Timing: Late
- Shape of Motion: Angular
- Change of Direction: Quick / Fast
- Roll Characteristic: Energy Retaining
EQUNOX
Strong Asym Torque
LAYOUT CHANGE – Earlier Roll
CHANGE MADE: From standard benchmark layout to a layout that promotes earlier roll
WHY IT MATTERS: Earlier flare use makes the core transition sooner
REACTION PROFILE: Reads the lane earlier, smoother backend
ARSENAL ROLE: Shifts the ball into a control role for heavier oil or flatter patterns
- Hook Phase Timing: Midlane + Controlled
- Shape of Motion: Smooth + Arc
- Change of Direction: Moderate / Medium
- Roll Characteristic: Continuous
EQUNOX
Strong Asym Torque
LAYOUT CHANGE – Later Roll
CHNAGE MADE: From standard benchmark layout to a layout that delays roll and stores energy.
WHY IT MATTERS: Delays the skid-to-hook transition
REACTION PROFILE: Pushes further downlane with a sharper move at the breakpoint.
ARSENAL ROLE: Fills a stronger angle/finisher slot when lanes open up.
- Hook Phase Timing: Late + Delayed
- Shape of Motion: Angular + Skid Flip
- Change of Direction: Immediate / Very Fast
- Roll Characteristic: Energy Retaining
EQUNOX
Strong Asym Torque
ORIGINAL CONDITION – Fresh Heavy Oil
LANE CONDITION: Fresh heavy oil (intended baseline).
WHY IT MATTERS: Higher oil volume delays friction, letting the ball store energy for a more powerful backend.
REACTION PROFILE: Skids cleanly through the heads, saves energy, and produces a stronger, more angular backend move.
ARSENAL ROLE: Ideal for fresh heavy oil conditions — establishes the ball’s designed motion before adjusting for breakdown or lighter volumes.
- Hook Phase Timing: Late + Delayed
- Shape of Motion: Angular + Skid Flip
- Change of Direction: Immediate / Very Fast
- Roll Characteristic: Energy Retaining
EQUNOX
Strong Asym Torque
CONDITION CHANGE – Fresh Medium Oil
CHANGE MADE: Same ball thrown on a fresh medium oil pattern.
WHY IT MATTERS: With less oil volume, the ball finds friction earlier.
REACTION PROFILE: Reads the lane sooner, smoother arc, less backend pop.
ARSENAL ROLE: Can potentially feel “too strong” — better to ball down or use something cleaner to retain energy.
- Hook Phase Timing: Midlane + Controlled
- Shape of Motion: Smooth Arc
- Change of Direction: Moderate / Medium
- Roll Characteristic: Continuous
EQUNOX
Strong Asym Torque
CONDITION CHANGE – Transition / Breakdown
CHANGE MADE: Same ball thrown after the lane has broken down
WHY IT MATTERS: Extra friction in the heads and track area causes early hook
REACTION PROFILE: Hooks earlier, burns energy, weaker finish downlane
ARSENAL ROLE: The ball that was perfect on the fresh feels flat — a reminder why arsenal versatility matters.
- Hook Phase Timing: Early
- Shape of Motion: Round
- Change of Direction: Smooth / Slow
- Roll Characteristic: Early Rolling
PHYSICS BLACKOUT
Strong Asym Torque
ORIGINAL SURFACE – 2000 Grit
FACTORY SURFACE: Factory box finish with 2000 grit
WHY IT MATTERS: Clean through the front with strong traction in the midlane, matches the ball’s intent as a heavy oil pearl piece.
REACTION PROFILE: Gets through the front before reading the mid lane with a smooth arc and continuous motion, ideal for blending heavier volumes.
ARSENAL ROLE: Baseline control on fresh heavy oil — benchmark motion for this ball’s design.
- Hook Phase Timing: Late + Delayed
- Shape of Motion: Angular + Skid Flip
- Change of Direction: Immediate / Very Fast
- Roll Characteristic: Energy Retaining
PHYSICS BLACKOUT
Strong Asym Torque
SURFACE CHANGE – 1000 Grit
CHANGE MADE: Sanded down from box finish to 1000 grit.
WHY IT MATTERS: Rougher surface creates earlier traction and stronger midlane read.
REACTION CHANGE: Picks up sooner, smoother shape, less backend pop.
ARSENAL IMPACT: Converts into a heavy oil control piece for flatter or tighter patterns.
- Hook Phase Timing: Midlane + Controlled
- Shape of Motion: Angular
- Change of Direction: Quick / Fast
- Roll Characteristic: Continuous
PHYSICS BLACKOUT
Strong Asym Torque
SURFACE CHANGE – Power Edge
CHANGE MADE: Polished to Power Edge finish
WHY IT MATTERS: Reduced friction in the front part of the lane, saving energy.
REACTION CHANGE: Delayed hook, sharper and more angular backend.
ARSENAL IMPACT: Expands usability to medium volumes and transition; makes the ball more versatile.
- Hook Phase Timing: Early
- Shape of Motion: Arc
- Change of Direction: Moderate / Medium
- Roll Characteristic: Continuous
PHYSICS BLACKOUT
Strong Asym Torque
ORIGINAL LAYOUT – Standard Roll
LAYOUT: Standard/benchmark drilling (neutral pin-to-PAP distance, balanced CG/PSA).
WHY IT MATTERS: Balances length with mid lane read and backend, giving a true read of the ball’s natural motion.
REACTION PROFILE: Smooth midlane read with controlled arc downlane.
ARSENAL ROLE: Establishes the Blackout as a reliable heavy-oil pearl option when you early hooking ball hooks too soon.
- Hook Phase Timing: Late
- Shape of Motion: Angular
- Change of Direction: Quick / Fast
- Roll Characteristic: Energy Retaining
PHYSICS BLACKOUT
Strong Asym Torque
LAYOUT CHANGE – Earlier Roll
CHANGE MADE: Adjusted layout that promotes earlier core transition
WHY IT MATTERS: Increases flare use earlier, making the ball pick up sooner.
REACTION CHANGE: Stronger midlane roll, smoother backend, less angular shape.
ARSENAL IMPACT: Converts the Blackout into more of a control piece for flatter or high-volume conditions.
- Hook Phase Timing: Midlane + Controlled
- Shape of Motion: Smooth + Arc
- Change of Direction: Moderate / Medium
- Roll Characteristic: Continuous
PHYSICS BLACKOUT
Strong Asym Torque
LAYOUT CHANGE – Later Roll
CHANGE MADE: Adjusted layout that delays roll and maximizes energy storage
WHY IT MATTERS: Keeps the core stable longer, storing energy for the breakpoint.
REACTION CHANGE: Longer push through the heads, sharper motion off the spot.
ARSENAL IMPACT: Turns the Blackout into more of an angle/finisher ball when lanes start to open up
- Hook Phase Timing: Late + Delayed
- Shape of Motion: Angular + Skid Flip
- Change of Direction: Immediate / Very Fast
- Roll Characteristic: Energy Retaining
PHYSICS BLACKOUT
Strong Asym Torque
ORIGINAL CONDITION – Fresh Heavy Oil
LANE CONDITION: Fresh heavy oil (intended baseline).
WHY IT MATTERS: Matches the intent of the Blackout — control through the heads with traction in oil and smooth midlane read.
REACTION PROFILE: Controls the front, reads in the midlane, smooth continuous arc downlane.
ARSENAL ROLE: Baseline heavy-oil option. Great when early reacting balls hook too soon.
- Hook Phase Timing: Late + Delayed
- Shape of Motion: Angular + Skid Flip
- Change of Direction: Immediate / Very Fast
- Roll Characteristic: Energy Retaining
PHYSICS BLACKOUT
Strong Asym Torque
CONDITION CHANGE – Fresh Medium Oil
CHANGE MADE: Same ball thrown on a fresh medium oil pattern.
WHY IT MATTERS: With less oil, the cover finds earlier friction, smoothing out the motion shape.
REACTION PROFILE: Reads the lane sooner, arcs smoother, backend motion softens.
ARSENAL ROLE: Can feel “too strong” or hard to keep from over reacting — better to ball down or use something with more length in these conditions.
- Hook Phase Timing: Midlane + Controlled
- Shape of Motion: Smooth Arc
- Change of Direction: Moderate / Medium
- Roll Characteristic: Continuous
PHYSICS BLACKOUT
Strong Asym Torque
CONDITION CHANGE – Transition / Breakdown
CHANGE MADE: Same ball thrown after the lane has broken down
WHY IT MATTERS: Extra friction in the heads and track area causes earlier energy loss.
REACTION PROFILE: Hooks early, burns energy, weaker finish downlane
ARSENAL ROLE: In transition, it can hook too early lose continuation, and have a hard time with carry.
- Hook Phase Timing: Early
- Shape of Motion: Round
- Change of Direction: Smooth / Slow
- Roll Characteristic: Early Rolling
