<html> <body> Ron, Very interesting demonstration - thanks for posting it! Can you tell us the approximate sample rib / soundboard crown radius? Or if you could provide the unloaded measurement of the difference from the bottom of the soundboard strip (at center) and the cord line to give an idea of how much crown was in the sample. What style rib was it - crowned on top?  Was there any "compression" style crowning in the combination? Don Mannino At 07:04 AM 10/29/2004, you wrote: <blockquote type=cite class=cite cite="">Yesterday I proved this to my satisfaction. I built and load tested a model of rib 6 (numbered from the back) for a Steinway D, attached to a 142 wide strip of 8mm thick Sitka spruce panel. This rib is 990 mm long overall (65 mm shorter than standard on account of the sound board cut-off), with an inner rim contact of 40 mm on the treble-bent side, and 30 mm on the new sound board cut-off. At 0.75 degrees of downbearing angle (a typical figure over this rib on a D), there will be 10.6 Kg down bearing from the treble bridge and 6.4 Kg from the bass. When we applied this load to the sound board test strip, with one end of the strip clamped to the bench and the other end free, it caused the free end to pull in 0.05 mm (2 thou).</blockquote></body> </html>