Not Every Polyester Ball Is Created Equal
About the Black Widow Spare+
Not every polyester ball is created equal. The Hammer Black Widow Spare+ pairs the iconic Gas Mask core with a polyester cover to create a uniquely versatile bowling ball. It delivers the accuracy bowlers demand for spare shooting while offering enough core dynamics to become a valuable option on extremely dry lanes and shorter patterns with less volume.
Whether it is used for converting corner pins or helping you navigate the toughest lane conditions, the Black Widow Spare+ is ready for the challenge. Wrapped in a striking white pearl finish with eye-catching sparkle, the White Diamond colorway is every bit as bold as the Black Widow name deserves. It is available from 10 to 16 lb with a two-year warranty.
Understanding the Hammer Gas Mask Core and Polyester (Plastic)
Hammer built the Black Widow Spare+ to be more than a spare ball. Specifically, the 16 to 14 lb weights carry the iconic asymmetric Gas Mask core (2.480 RG, .058 differential, .013 intermediate differential at 15 lb), the same dynamics as Hammer’s high-performance Black Widows, under a polyester cover at a 500, 1000, 2000 Siaair / Factory Polish finish. The plastic cover keeps the ball straight for spares, while the core gives it enough motion to be a real option on extremely dry lanes and short, low-volume patterns. The 13 and 12 lb weights use a dedicated core, and the 11 and 10 lb weights use a low-differential pancake block for the straightest possible roll. The full per-weight numbers are listed below.
The Iconic Black Widow Core, Now in a Polyester Ball
At the heart of the Black Widow Spare+ (16 to 14 lb) is the iconic asymmetric Gas Mask core, the engine that made the Black Widow line famous. At 15 lb it measures a 2.480 RG, a .058 differential, and a .013 intermediate differential, numbers you normally find in a high-performance reactive ball, not a spare ball.
Paired with a polyester cover, that core does something a pancake-block plastic ball cannot: it gives the Black Widow Spare+ enough core dynamics to become a valuable option on extremely dry lanes and shorter patterns with less volume. The 13 and 12 lb weights carry a dedicated core (2.589 RG, .043 differential), and the 11 and 10 lb weights use a traditional low-differential block (.002) for the straightest roll.
A White Diamond Polyester Cover Built for Accuracy
Wrapping the Gas Mask core is a polyester coverstock at a 500, 1000, 2000 Siaair / Factory Polish finish. Polyester does not absorb oil or create friction the way a reactive cover does, so the ball rolls straight and true, exactly what you want when you are converting corner pins and single-pin spares.
The White Diamond finish is a white pearl with eye-catching sparkle, as bold as the Black Widow name deserves. Because the cover is plastic, it is also the ball to reach for on the driest lanes and shortest patterns, when even your weakest reactive ball hooks too much.
Black Widow Spare+ Specs
RG and differential vary by weight. Specifications provided by the manufacturer.
Who This Ball Is Right For
Good to Know Before You Buy
BowlersMart Tips: Where the Black Widow Spare+ Fits in Your Hammer Arsenal
Where It Fits in Your Arsenal
In the Hammer lineup, the Black Widow Spare+ is the spare ball and the driest-lane option. It sits at the bottom of the bag under your reactive equipment: open with a Zero Mercy Tour or Zero Mercy Hybrid on the fresh, and reach for the Spare+ for every corner pin and on the days when the lanes are bone dry.
Surface Adjustments
The factory polish is the box reaction and the one you want for spares: keep it polished for the straightest roll. If you use the Spare+ as a dry-lane strike ball and want a touch more read, your pro shop can take the surface down slightly, but most bowlers should leave it alone.
Coverstock Care
Polyester covers do not absorb oil the way reactive covers do, so the Black Widow Spare+ needs less maintenance than your strike balls. Wipe it down after every session to keep the White Diamond finish sparkling and the roll consistent.
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Shop With Confidence at BowlersMart
The Hammer Black Widow Spare+ Bowling Ball ships free with no minimum purchase and is backed by our 60-day return policy. As an authorized Hammer dealer, every ball is genuine and covered by the full two-year Hammer warranty. Place your order before 2 PM EST and it ships the same day.


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