List 4 meter radius ?? Isnt that rather a lot ? Your point about not being able to tell whether the other ribs were crowned or not brings me to ask the list how one can really tell for sure whether ribs have been pre crowned or not. I assume you have to have them removed from the panel to have a good enough look ?? Up to now I have had basically 2 things to go on. Dimensions are evidently a good hint.. tho not decisive. That is to say that it seems likely that shallow and wide ribs were used in non rib crowned applications... because they bend so easily. Secondly... I have this idea that if you take a rib and press it so that its grain along the rib is all horisontally oriented... then if the rib is flat well... it was flat... if there is curvature to the glue surface then it was crowned... does this make sense ? Cheers RicB Ron Nossaman writes: I replaced the board in an old Knabe grand a few years back. The top four treble ribs were not only crowned (about 4 meter radius, at that), but laminated. I couldn't tell whether any of the other ribs were crowned, but the board was concave under bearing load. There's a difference between rib crowned and rib supported. These boards are still primarily panel supported, crowned ribs or not.
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