Downbearing Calculator

Downbearing Calculations are used to establish and optimum plate or bridge height.

General downbearing angles (DB Angle) in degrees are as follows:

Minimum Crown: 0.5
Medium Crown 1.0 - 1.5
Maximum Crown: 2.0
(or top treble section)

Calculations are per string

Tension (Lbs.)
DB Angle
Backstring Length (in.)
Down Force (Lbs.)

Sine of Angle 1.5 degrees (.02626) * Backstring of 4.00 in. = Offset of .105
Tension of 160 Lbs. * Sine of Angle 1.5 degrees (.02626) = Force down on bridge/board of 4.2 Lbs.
Note:When setting downbearing, twist drills can be used for measuring offset instead of specialized downbearing gages. Also, entering total Tension of 35000 will yield total Down Force of 919.1 Lbs.

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