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View Full Version : Hack job spoke tension gauge calibrator


staggerwing
08-17-2016, 08:31 AM
Been building some more wheels recently, and wanted to verify the accuracy of my Park spoke tension gauge. Cooked up a simple lever arm fixture using some scrap materials in the shop. FWIW, as shown, the mechanical advantage is 30x (15" lever arm, with 0.5" pivot to spoke offset), although there are indents for 10x and 20x too. Sporting a 4kg mass (3880ml water in a 120g jug), for a 120kg load on the 14gauge spoke.

FWIW, over a couple of different spokes, both DB and straight gauge, and 80 and 120kgf loadings, the gauge was reading 2-4% high, which I thought was rather good. Extended the tension screw 1/2 turn, and now it is spot on.

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Fatty
08-17-2016, 08:49 AM
Pretty cool. Like the Park blue bar clamp.

Mark McM
08-17-2016, 09:18 AM
Isn't it great when basic principals of physics work?