GripLoc’s Quick Change Thumb Insert

Realizing the most common problem that the majority of bowlers have is hand expansion or contraction due to various things while bowling and Solved the Problem.

The Outer sleeve is made of a material that is strong but can be trimmed if necessary after being installed. The Inner Sleeve is a urethane, 75 in hardness and is compatible to the current solid urethane slugs being sold by companies in today’s market. Both parts are being manufactured here in the United States.

GripLoc Products took its Innovated idea and developed the first Quick Change Urethane Thumb Insert that requires no hardware to secure it into place. The process was to develop a product that could be installed by any pro shop, be used from ball to ball and the thumb size could be quickly changed with no tools within seconds.

This product has been tested by one of the leading Major Bowling companies with us to insure it would withstand today’s standards among bowlers. The close tolerance standard that GripLoc Products used in developing their product, will keep it on top.

Drilling Specifications

Thumb Outer Sleeve

Drilling the thumb outer sleeve has a standard outer diameter of 1-3/8″. The hole should be drilled 1 3/8″ in diameter the same size as the outer sleeve to a depth of 2 7/16″.

Remember using a sharp drill is important to the installation. Worn or dull drills will cause the hole to be undersized causing the insert to collapse after you press it in causing the interchangeable grip to be tight and not work properly.


Thumbholes should be slightly bevelled and dust free before securing outer sleeve in place. Using rough sandpaper on outer diameter of the sleeve will make the sleeve adhere to the ball better.

A medium cyanoacrylate adhesive (super glue) can be used to secure in place but an epoxy is recommended. Apply glue sparingly around the interior of the thumbholes before pushing sleeve into place. Remember keep the top of the outer sleeve flush with the lower part of the thumbhole. Trim any excess off.