Ordering new rubber rings using old rings as a guide is sometimes impossible
due to broken, non-elastic, or missing rings. The following chart will help
you determine the correct sizes for all your rings. Measure the
circumference around the posts. Find that size along the left side and note
where that size intersects the red line. Follow that point down. That is
the size of your new rubber ring that will fit. These numbers are the
inside diameter of new rubber rings, which is how sizes are denoted. Note
that small sizes smaller than 1" may be difficult to determine on the chart,
but are easy once you know the rules.
Mini-posts with pointy tops take either 27/64" (common) or 23/64". The rare
smaller size is for those places where the normal size is too large.
Mini-posts with a short flat top takes either a white or black Gottlieb #962
Most single playfield posts take 5/16", but will take the slightly larger
3/8" rubber. Be aware that in some places the 3/8" rubber will not leave
enough clearance--it is larger. Some people prefer 3/8" everywhere
because it gives a little more bounce.
Narrow cylinder-style single playfield posts take 3/16".
Bally mushroom bumpers take 7/16". Be sure to change these as they are
often overlooked when changing rubber because they are not seen, hiding
under the "mushroom".
Two normal playfield posts nearly touching will take 3/4".
2" flippers will take one or two 1" each, or some prefer 1-1/4"
3" flippers by all but Gottlieb take 1/2" x 1-1/2" flipper rubbers, but can
take 3/8" x 1-1/2"
3" Gottlieb flippers can take 1/2", but have a better fit with the 3/8" x
1-1/2" flipper rubbers
Don't forget to get a new plunger tip and rebound rubber (the thick
black/brown rubber disk that the ball first hits on most playfields).
For example if you have three posts for one rubber and the circumference
around the three is 15.0", then you need a new 3.5" rubber ring.