I service a lot of these and have come to the conclusion that the barrel hook connection was under-engineered. The majority of the failures involve the outer terminus of the spring being ripped off. I have frequently made a new hole end in order to save the customer a few bucks. I thought that was what I was going to be doing today when servicing a CDIA clock and was surprised to find the springs were fine but both barrel hooks ripped out! I was almost pleased because I have more barrels than springs. Just a pointless whine I guess, but I will add it seems crazy to have to dismantle a CDIA to the last screw just to replace mainsprings? -Cort
