It was on a multitool I happened to have thrown in my bag for the ride...had a full pannier with a few tools, snacks, and a quart of Ice Tea...all that extra weight might have "helped" break the spoke...but probably just a matter of time, it IS an 11 year old wheel, I've broken another spoke on that wheel (again with a bit of a load on the rack...over a bump....PING!!!!)