{"merchant":{"slug":"bowlersmart","name":"BowlersMart","domain":"www.bowlersmart.com"},"id":"1534552","sku":"BBMRGW","gtin":null,"name":"Roto Grip Perfect Gem Bowling Ball","brand":"Roto Grip","categories":[{"name":"Asymmetrical Core Bowling Balls","slug":"asymmetrical-core-bowling-balls"},{"name":"Ball Add-Ons","slug":"ball-add-ons"},{"name":"Bowling Balls","slug":"bowling-balls"},{"name":"Bowling Balls for Two-Handed Bowlers","slug":"two-handed-bowling-balls"},{"name":"Bowling Brand","slug":"brands"},{"name":"Heavy Oil Bowling Balls","slug":"heavy-oil-bowling-balls"},{"name":"High Performance Bowling Balls","slug":"high-performance-bowling-balls"},{"name":"MRP/MAP","slug":"mrp-map"},{"name":"Pre-Orders / New Releases","slug":"new-bowling-balls"},{"name":"Roto Grip","slug":"roto-grip"},{"name":"Roto Grip Bowling Balls","slug":"roto-grip-bowling-balls"},{"name":"Solid Reactive Bowling Balls","slug":"solid-reactive-bowling-balls"},{"name":"Top Selling Bowling Balls","slug":"top-selling-bowling-balls"}],"buy_url":"https://www.bowlersmart.com/product/roto-grip-perfect-gem-bowling-ball/","pages":{"html":"https://ittems.com/bowlersmart/p/roto-grip-perfect-gem-bowling-ball","md":"https://ittems.com/bowlersmart/p/roto-grip-perfect-gem-bowling-ball.md","json":"https://ittems.com/bowlersmart/p/roto-grip-perfect-gem-bowling-ball.json"},"price":{"min":199.95,"max":199.95,"currency":"USD"},"availability":"instock","checked_at":"2026-10-15T22:14:34.802393+00:00","source_updated_at":"2026-10-15T22:13:13+00:00","summary":"What should I know about the Perfect Gem? •Asymmetric GEM + A.I. Core: low 2.49 RG and a massive .057 differential for heavy flare •All-new nano-free E-R1 Solid Reactive cover at a 2000-Grit Abralon finish •The cleaner, stronger, more continuous evolution of the Gem for medium-heavy to heavy oil","specs":[{"key":"Brand","value":"Roto Grip"},{"key":"Bowling Ball Coverstock Type","value":"Solid Reactive"},{"key":"Bowling Ball Cover Name","value":"Roto Grip E-R1 Solid Reactive"},{"key":"Bowling Ball Core Shape","value":"Asymmetrical Core"},{"key":"Bowling Ball Core Name","value":"Roto Grip GEM A.I. Core"},{"key":"Radius of Gyration: RG (15LB)","value":"2.49"},{"key":"Differential: Diff (15LB)","value":".057"},{"key":"Mass Bias Strength","value":".017"},{"key":"Flare Potential","value":"4 - 5 Inches"},{"key":"Surface Finish","value":"2000 Grit"},{"key":"Preferred Lane Conditions","value":"Heavy Oil, Medium - Heavy Oil"},{"key":"Bowling Ball Color","value":"Black, Pink"},{"key":"Ball Performance Level","value":"High Performance Bowling Balls, Roto Grip HP4 Bowling Balls"},{"key":"Scent","value":"None"},{"key":"Release Date","value":"October 2026"}],"variants":[{"sku":"BBMRGW16","gtin":"887970781319","label":"16LB","price":199.95,"stock":26,"options":{"Ball Weight":"16LB"},"availability":"instock","regular_price":289.95},{"sku":"BBMRGW15","gtin":"887970781296","label":"15LB","price":199.95,"stock":1802,"options":{"Ball Weight":"15LB"},"availability":"instock","regular_price":289.95},{"sku":"BBMRGW14","gtin":"887970781265","label":"14LB","price":199.95,"stock":969,"options":{"Ball Weight":"14LB"},"availability":"instock","regular_price":289.95},{"sku":"BBMRGW13","gtin":"887970781234","label":"13LB","price":199.95,"stock":57,"options":{"Ball Weight":"13LB"},"availability":"instock","regular_price":289.95},{"sku":"BBMRGW12","gtin":"887970781203","label":"12LB","price":199.95,"stock":48,"options":{"Ball Weight":"12LB"},"availability":"instock","regular_price":289.95}],"images":[{"alt":"Roto Grip Perfect Gem bowling ball","url":"https://www.bowlersmart.com/wp-content/uploads/2026/08/roto-grip-perfect-gem-bowling-ball.webp"},{"alt":"Roto Grip GEM + A.I. Core (16-14 lb)","url":"https://www.bowlersmart.com/wp-content/uploads/2026/08/roto-grip-perfect-gem-core.webp"},{"alt":"Roto Grip Perfect Gem asymmetric core (13-12 lb)","url":"https://www.bowlersmart.com/wp-content/uploads/2026/08/roto-grip-perfect-gem-core-13-12lb.webp"}],"release_date":"October 2026","description":"The Cleaner, Stronger Evolution of the Gem for Heavy Oil\n\nAbout the Perfect Gem\n\nThe evolution of the Gem line reaches its peak with the Roto Grip Perfect Gem. Roto Grip took the DNA of the original Gem core and strategically altered its density to integrate with its A.I. Core Technology, a precise calibration that enhances the core's natural physics for a more continuous motion and maximum energy transfer through the pins: the most \"perfect\" ball motion Roto Grip has engineered to date.\n\nSurrounding that high-torque weight block is the brand-new E-R1 Solid Reactive coverstock (EXTREME-Response Version 1), a nano-free formulation that puts a completely different footprint on the lane than Roto Grip's previous-generation materials. Finished at 2000-Grit Abralon and calibrated for medium-heavy to heavy oil, the Perfect Gem is for the bowler who craves maximum reaction without the early burnout. It is the cleaner, stronger, and more versatile version of a legend, in Pink / Rose / Onyx.\n\nUnderstanding the Roto Grip GEM A.I. Core and Roto Grip E-R1 Solid Reactive\n\nRoto Grip built the Perfect Gem for medium-heavy to heavy oil with a cleaner front and a stronger, more continuous finish than the original Gem. Specifically, the asymmetric GEM + A.I. Core has a low RG and a massive differential (2.49 RG, .057 differential, .017 intermediate differential at 15 lb), so it revs early, flares hard, and keeps driving through the pins, while the E-R1 Solid Reactive cover at a 2000-Grit Abralon finish glides through the heads and preserves an extreme response to friction down lane, even as the pattern transitions. The 13 and 12 lb weights use a dedicated asymmetric core tuned for those weights. The full per-weight numbers are listed below.\n\nThe Gem Core, Recalibrated With A.I. Core Technology\n\nAt the heart of the Perfect Gem is the asymmetric GEM + A.I. Core. Roto Grip kept the DNA of the original Gem core and strategically altered its density to integrate with A.I. Core Technology. At 15 lb it measures a low RG of 2.49, a massive .057 differential, and a .017 intermediate differential, numbers that produce heavy flare and an early, strong read with real continuation.\n\nThat precise calibration enhances the core's natural physics, creating a more continuous motion that maximizes energy transfer through the pins rather than rolling out. Because the core is asymmetric it has a defined preferred spin axis, so layout has a real say in how early and how hard it revs up; your pro shop can tune the pin and PSA to your game. The 13 and 12 lb weights carry a dedicated asymmetric core (2.57 RG, .032 differential at 13 lb) built to give lighter-weight bowlers the same shape.\n\nA Brand-New Nano-Free Solid With an Extreme Response Down Lane\n\nWrapping the GEM + A.I. Core is Roto Grip's all-new E-R1 Solid Reactive coverstock, EXTREME-Response Version 1. This nano-free formulation creates a completely different footprint on the lane than previous-generation materials, altering the surface contact zone to blend seamless front-lane cleanliness with a more extreme response to friction down lane.\n\nFactory-finished at a 2000-Grit Abralon baseline for an optimal balance of traction and recovery, the E-R1 cover glides through the heads and preserves its extreme down-lane response even as the oil pattern begins to transition. Leave the box surface for the strongest medium-heavy to heavy oil reaction, take it lower for even more traction, or polish it up at your pro shop for a cleaner, longer read when the volume drops.\n\nPerfect Gem Specs\n\nRG and differential vary by weight. Specifications provided by the manufacturer.\n\nWho This Ball Is Right For\n\n✓Tournament Players: A first-ball-out-of-the-bag heavy oil asymmetric with the continuation to carry on fresh, heavy patterns\n\n✓Speed-Dominant Players: The low RG and .057 differential rev up early, while the clean E-R1 cover still gets down the lane\n\n✓Balanced Players: Versatile enough to dial across medium-heavy to heavy patterns with simple surface adjustments\n\n✓Gem Loyalists: The cleaner, stronger, more versatile version of the ball you already trust\n\nGood to Know Before You Buy\n\n·Strong, aggressive motion: This is a high-flare piece built for traction. If you want a controlled, lower-hook reaction, a lower-differential ball will suit you better.\n\n·Ships sanded for traction: The 2000 Grit Abralon finish is built to grip in oil. Polish it for more length when the volume drops.\n\n·Asymmetric layout sensitivity: Layout choices shift the reaction more than on a symmetric ball. Match the pin and mass bias to your game with your pro shop.\n\n·Colors vary: Actual colors vary somewhat from the photos shown; no two balls come out of the mold exactly alike.\n\n·Tiny pit holes are normal: A few tiny pit holes in the coverstock are a normal part of the manufacturing process.\n\n·Sold undrilled: Ships without finger holes, so it can be fitted to your hand and span.\n\nBowlersMart Tips: Where the Perfect Gem Fits in Your Roto Grip Arsenal\n\nWhere It Fits in Your Arsenal\n\nIn the Roto Grip lineup, the Perfect Gem is the heavy oil HP4 asymmetric at the top of the bag. It attacks the freshest, heaviest volume with an early, strong read and relentless continuation, then, as the lanes transition, you step down to the HP3 Wicked Gremlin or a cleaner piece like the Transform Pearl for more length and a sharper backend.\n\nSurface Adjustments\n\nThe 2000-Grit Abralon finish gives the Perfect Gem strong, controllable traction out of the box. Take it lower for more bite on the heaviest oil, or polish it up for a cleaner, longer read when the lanes transition. Have surface changes done at your pro shop for an even, consistent finish.\n\nCoverstock Care\n\nThe E-R1 solid cover is a strong absorber and pulls oil out of the lane quickly. Wipe the Perfect Gem down after every set and deep clean it periodically to preserve the extreme down-lane response that defines the ball.\n\nEarn points on every Roto Grip purchase through the Striking Rewards loyalty program. Every ball you add to your arsenal builds toward your next reward.\n\nShop With Confidence at BowlersMart\n\nThe Roto Grip Perfect Gem Bowling Ball ships free with no minimum purchase and is backed by our 60-day return policy. As an authorized Roto Grip dealer, every ball is genuine and covered by the full one-year Roto Grip warranty. Place your order before 2 PM EST and it ships the same day.\n\nWeight\nRadius of Gyration (RG)\nDifferential\nMass Bias\n\n16 lbs\n2.49\n.055\n.017\n\n15 lbs\n2.49\n.057\n.017\n\n14 lbs\n2.52\n.056\n.016\n\n13 lbs\n2.57\n.032\n.010\n\n12 lbs\n2.59\n.029\n.008","policies":[{"text":"Free ground shipping on US orders, no minimum, 48 contiguous states and military APO/FPO. To Alaska, Hawaii, Puerto Rico and Guam bowling balls ship for $24.95 per ball, most other items free; oversized roller bags cost extra there. International orders pay the rate shown at checkout, duties paid locally.","title":"Shipping","source_url":"https://www.bowlersmart.com/shipping-information/"},{"text":"In-stock items ordered by 2PM EST Monday to Friday ship the same day, later orders the next business day. Carriers USPS, UPS, FedEx. Standard delivery 3 to 7 business days; expedited options at checkout.","title":"Processing and delivery","source_url":"https://www.bowlersmart.com/shipping-information/"},{"text":"60 days from delivery for US customers on new, unused items in original packaging, free prepaid return labels. Drilled bowling balls cannot be returned or exchanged. Shoes must have been tried on a clean, dry surface. Manufacturing defects and shipping damage go through the defect claim process.","title":"Returns","source_url":"https://www.bowlersmart.com/return-exchange-policy/"},{"text":"Credit and debit cards, PayPal, Apple Pay, Google Pay, Venmo, Amazon Pay, and buy now pay later through Affirm, Afterpay and Klarna.","title":"Payment","source_url":"https://www.bowlersmart.com/payment-options/"},{"text":"Pro shops inside bowling centers in 10 US states fit, drill and service equipment; a ball bought online can be drilled there.","title":"Pro shops","source_url":"https://www.bowlersmart.com/locations/"},{"text":"www.bowlersmart.com is the only website of BowlersMart. Lookalike domains are fraudulent.","title":"Identity","source_url":"https://www.bowlersmart.com/resources/scam-awareness/"}]}