Doing the Shimmy Thang

Chris Pollak explains the technical aspects and history of mast shims in Thistle racing, including the rules that govern their use. He traces the practice back to the late 1970s when North Sails began experimenting with mast bend control, and outlines the specific limits and restrictions under which shims can be used. Key points include that shims cannot exceed 3/16" total thickness and cannot be changed during racing.

This is a summary. The full article text is © the Thistle Class Association — read the original scan via the link above.

• mast shims
• boat setup
• technical rules
• measurement
• tuning