I have to admit I didn't think about speed when it comes to brakes. Thanks to another thread at BF, I got looking at the Electra Cruiser line.
On one of Electra's Cruiser
webpages, the braking systems change depending on the potential speed of the bike (or user), it would seem.
1 speed cruisers get a rear coaster brake.
3 speed cruisers get a front rim brake and a rear coaster brake.
7 speed cruisers get front and rear rim brakes.
7 speed fat tire cruisers get front and rear discs (Due to tire width making rim brakes problematic?).