I keep my leftover chain piece, a pair of spare quick links, and a chain tool in my roadside bag.
Haven't broken a chain yet, but it's not unheard of, and if you're 30 mi from home and can make a splice, it saves an embarrassing phone call.
I also think many of the 10-sp quick links are not re-usable, so might buy a card of 4 to have around.
KMC - $8 for a card of 2 sets - cheap.
Last edited by bulldog1935; 08-01-16 at 07:36 PM.