Depending on the size of your kid’s bike, it will fit in a BBS or BBM. Not all kids' bikes will fit in a BBS, but some will not need a box as big as a BBM. We suggest you measure your kid’s bike and compare its size to the dimensions of our BBS and BBM before ordering. When packing a kid’s bike, expect to remove one or both wheels depending on the size of the bike and which box you pick.