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K55 - Cushions. Superspeed Vrs ? Similar content
- By bradsh98
- Talk To A Mechanic
- 9 Replies
Not all K55 profiles are the same. Intercontinental 66 has a much larger nose radius than Superspeed. though, the nose height for Artemis Intercontinental 66 (K55) and Superspeed (K55) should be pretty close to the same, when installed on the same sub-rail.So the nose height is slightly different between the Artemis and a Superspeed? So that must mean a K55 can vary in nose height depending on the manufacturer, I always thought that all K55's were the same. Or is it that the Artemis IC K66 is not an exact copy of a K55, and why would Artemis flop the 55 and 66 numbers around after putting "Intercontinental" before it?? Its all very confusing.
It is important to note that Glen and Mark sparked the widespread desire for Brunswick sub-rail modification (or calibration, as some refer to it), approximately 17 years ago. At that time, Artemis Intercontinental 66 were the cushion of choice. Being a carom cushion with a large nose radius, they tend to bank fairly springy. Because of that, it is preferable to set the height just a touch higher than a standard cushion. Setting the nose height for an Intercontinental 66 at 1 29/64", with a sub-rail height of 1 11/16" makes it play pretty well. And so, the Blue Label Diamond specification was born.
But, where does that 1 29/64" nose height come from? From Brunswick. That was the original Brunswick specified nose height, using a 1 23/32" sub-rail height. The tolerance is +1/32"/-1/64". Often times, when we modify these Brunswick rails, that's the nose height target that most of us will shoot for, to maintain consistency with Glen and Mark, regardless of which cushion we use. When we modify these rails, we drop the height of the sub-rail to 1 11/16" (1/32" lower than the manufactured height). This is to provide a consistent height at the top of the sub-rail. Typically, when you lower the height of the sub-rail, It's most desirable to also reduce the nose height, to maintain consistent rebound speed and angle. In theory, the reduction in nose height should be about 36% of the reduction in sub-rail height. That said, a Brunswick Superspeed cushion, mounted on a 1 11/16" sub-rail, should have a nose height of 1.442" (1 7/16").
Because there are no agreed upon written standards, there are still a large number of people that believe that the nose height on a Gold Crown should measure in the range of 1.406-1.438". What is correct? Who knows... But, in order to maintain some sort of consistency, we should follow a standard. Since Glen and Mark have spoken the loudest, It's not a bad idea to follow their lead. Especially considering that Glen developed the rail specifications for the Blue Label Diamond and Mark developed the rail specifications for the Gold Crown VII.
