Originally Posted by Alan
I was wondering about that the other day! No rear brakes on (most?) tadpoles? So, does the steering pull when only one brake is applied? Can you steer by braking?
Commonly known as brake steer; some recumbent trikes have this worse than others. It puts lateral force on the rear wheel, the "rudder" and if it gets light or slips on leaves or something, it can angle the trike a bit. It is not serious when slowing but you want control of both front brakes when hitting them harder. My trikes exhibit very little brake steer. There is also a safety factor in having 2 brakes levers for 2 brakes... in case one cable fails, you still have brake control on the other wheel.
Brakes on the back of a recumbent trike have only 2 purposes, 1) a drag brake for long downhills when you don't want to cook your front brakes (uses a thumb shifter for actuation), common on touring setups, or 2) Stunts. The rear wheel is light enough under braking conditions to slide and come around if you lock it up. Something like turning brakes in a sandrail.