"First of all, try decaf :) It isn't you. Since they started heat-treating rims, they have become very brittle and prone to cracking. Most of the ones I see cracked are Mavics, but that may be because they are more common. Heat treating is a VERY precise process- the machinist's handbook devotes chapters to it- if anything in the process is not perfect the alloy will assume characteristics that may be undesirable. Sometimes it is intergranular corrosion and sometimes it may be over brittle. Heat treating is about making the molecules do what you want them to do and some days they just want to p---s you off. The rear wheels crack more often because they take more strain. Simple. I bet if the companies could track cracked rims, they would find out they were in the same batches of heat treatment. Corroded wing spars recently found on 1946 aircraft were traced to a bad batch of heat treat in 1945. I am glad your Quartz hub is still working, I had really bad luck with a couple a few years back and swore off them. Relax, it is not your wheelbuilding. Blame the lack of spokes and glass-like rims."
She also said she's been invited to an estate clearance of sorts.
"The last time I did that I came home with two Paramount track tandems, a Lejeune track bike and a van load of TA cranks and Simplex derailleurs."
I love her garage.