Originally Posted by pdlamb

Alex rims, while they're inexpensive, are usually built stouter than higher-priced rims. This is where a spoke tensiometer can help, or failing that, a musical tuner. Unless you've ridden over curbs or canyon-sized potholes, you've exceeded the upper limit on spoke tension, which cracked the rim. As a fellow clyde, I can appreciate your need to increase spoke tension to prevent spoke breakage from cyclic stressing, but as you've found out, too much is just as bad as too little.