Do you own the hubs and do you need a spare wheel set?
From a pure cash flow basis it probably isn't worth doing but, like lots of guys, I like to build wheels. I'd do it in a heartbeat.
Anybody want to buy a set of lightly used Open Pro's laced to brand new Tiagra hubs?
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My greatest fear is all of my kids standing around my coffin and talking about "how sensible" dad was.