JoPo bowling grips serve different jobs. A solid slug gives a pro shop material to drill for your thumb. A TWIST inner carries the fitted thumb hole in a removable part. An outer sleeve receives that inner inside the ball. Buying the right piece starts with knowing which part of your setup you want to change.
The useful question is how often you need to move or adjust your thumb fit. A bowler switching between several balls has different needs from someone using one ball each week. This guide explains the options in the GCA JoPo collection and what to discuss with your driller before ordering.
How JoPo TWIST works
The TWIST system uses an outer and a removable inner. The outer is installed in the bowling ball. The inner holds the thumb fit and can move between balls fitted with compatible outers. You still need a pro shop to check the fit and prepare each ball.
JoPo describes a threaded locking design that requires a full rotation to remove the inner. Its purpose is to keep the removable part secured during the delivery. See the JoPo TWIST system overview for the manufacturer explanation and installation resources.
Start with the JoPo Twist Outer when discussing a new ball installation. Buying an inner alone does not equip a ball that lacks the matching outer. Ask your driller to list the parts and fitting work for every ball you plan to use.
Solid slug, blank inner, or inner with a slug
The JoPo Solid Slug is the raw thumb fitting component. GCA lists four diameter choices and multiple colors. A slug by itself is not a complete interchangeable system. Its listed diameter describes the material your driller starts with, rather than a finished hole sized for your thumb.
The JoPo Twist Inner Blank gives your pro shop an unfinished inner to prepare. Confirm which additional parts and work your chosen fit needs. JoPo identifies this blank as compatible with its Twist Outer in the manufacturer blank inner details.
The JoPo Twist Inner with a one and one quarter inch slug combines the inner and slug. It still needs to be fitted to your hand. The included slug removes one item from the parts list, but does not replace measuring, drilling, or checking the release.
GCA also carries the inner with a one and three eighths inch thumb solid. JoPo lists larger thumbs and more extensive bevel work among its uses. Let the driller choose the required material diameter from the actual fit. Read the manufacturer size guidance before choosing by the number alone.
What the TWISTED series changes
The TWISTED series adds mixed color designs to the JoPo range. The manufacturer describes assorted colors, with pictured combinations serving as examples. Choose this range for its appearance after confirming the component you need.
There is a key installation detail. JoPo states that the TWISTED inner with a slug comes preglued. A removable inner does not mean every part of the assembly uses no adhesive. The official TWISTED inner description also identifies compatibility with the JoPo Twist Outer.
GCA lists the TWISTED inner with slug and a separate TWISTED outer. Match the exact item, quantity, and color selection on the listing. Do not assume a manufacturer bulk pack and a retailer listing contain the same number of pieces.
Who benefits from interchangeable thumb inserts
Consider TWIST if you use your thumb and regularly change balls. Moving one fitted inner between compatible balls gives you a way to carry that thumb fit with you. Each ball still needs its own setup checked. The insert does not set the finger holes or the span between fingers and thumb.
A second use is having different fitted inners available when thumb size changes during play. JoPo describes this use in its inner with slug guidance. Work with the shop to decide what each inner should do. Label them so you know which fit you are selecting.
If you use one ball and have a stable fit, ask whether a conventional slug already meets your needs. If your delivery does not use a thumb, an interchangeable thumb system does not address your finger fit. Put the fitting budget toward the part of the ball you actually use.
Plan the fitting and the full cost
Bring your current ball to the appointment. Explain when the fit feels wrong and whether the problem changes through a session. Ask the shop to evaluate the existing drilling before buying replacement parts. A new insert cannot by itself diagnose a release problem.
Get a quote that separates parts from labor. Include the outer for each ball, fitted inners, and any work needed on existing holes. A component price is not the total cost of a finished setup.
Keep spare inners together in a dedicated accessory space. When deciding how much equipment to carry, use the bowling bag buying guide to compare totes and rollers. Choose storage around the balls and small parts you actually bring.
FAQ
What are JoPo grips
JoPo makes bowling grip components and accessories. Its TWIST range is an interchangeable thumb system. A solid slug, inner, and outer are distinct parts, so check the full product name before ordering.
How do JoPo interchangeable thumbs work
A fitted inner locks into a compatible outer installed in the ball. The inner can be removed and transferred to another prepared ball. Have your pro shop demonstrate correct seating and removal.
Do JoPo grips come drilled
The blanks and slug assemblies discussed here are fitting components. They are not a finished thumb hole matched to your hand. Arrange drilling and fitting with your pro shop.
Are JoPo TWISTED grips glue free
JoPo says its TWISTED inner with a slug is preglued. The inner is removable from the outer, but that feature does not make the whole installation adhesive free.
Are JoPo grips worth it for one ball
They may suit a bowler who needs alternate fitted inners. If you have one ball and a stable thumb fit, compare that benefit with the full installed cost before changing systems.
Choose JoPo components around a fit your pro shop has checked.
