What I have found from my research is that tying and soldering is a tradition for track riders, primarily large-pack events on small tracks, at a time when rims were not as strong as they are today. Because of the conditions, most observers would think that the tying and soldering was for extra strength. Actually, it seems that it is more for the convenience of the mechanic. When built with hex-head spokes like the classic Robergel Sport, a broken rim on a tied and soldered wheel can be removed and replaced very quickly using a hex driver and a drill, probably a push drill, but a reversible electric or pneumatic drill will also speed the process.
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