>I see, so there is a large "by feel" component in prestresssing the board. >I can accept that. So then you pound on the board while inserting the >wedges until it feels right and then set the bearing. Partly. > What relevance, >then, is the amount of deflection. That's the other part. You can't expect an old board to be as stiff, with as much remaining crown as a new board. Nor can you expect a new board made as a copy of the existing board to have the same stiffness at the same deflection as a completely redesigned board with an entirely different rib set and crown plan. Nor can you assume different boards, each with specifically designed rib sets to have identical characteristics. There just aren't any universal checklist numbers and procedures that use one indicator in all instances. The entire system must be taken into account (or as much of it as you can conjure up), using the indicators of feel, resulting deflection, back scale length, and intended design parameters as indicators. New , old, or entirely different than anything ever made, it requires some thinking and evaluation. Ain't no ticket to ride. You have to make decisions. >For example, David Hughes writes that >he aims for about 3mm at the centermost strut. Is this, then, just a check >to be sure that the board, when stressed to your satisfaction by feel, >hasn't moved farther than you anticipated serving as a general indication >of stiffness? Based on what? New board? Old board? What crowning method and radii in what sections? Rib loading? Rib dimensions and crown height? That 3mm has a whole lot of assumptions and qualifications behind it that weren't listed. Ron N
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