There's a reason for this, and it's not so much how much water you drink on your ride. What happens is that when you assume the reclined position typical of trike riding and pedal, your body senses a relative fluid overload as the blood that normally sits pooled in your legs gets returned to the general circulation by both the position and the contracting muscles in your legs. In response, you secrete less of a hormone called ADH, which signals your body to make more urine to decrease the overload. Your body responds over a matter of an hour or so, your bladder fills, and you pee. Then when you get home, you stand up and your body senses a fluid underload as the blood resumes its normal position in your legs. This signals an increase in ADH, to decrease urine production, and also increases your thirst. Thus, an hour or so after returning home, you get much thirstier than normal, and pee less than usual for the next few hours. The trick in warm weather when you are sweating a lot is to balance all of this fluid shifting around with your fluid intake so you don't get dehydrated either during or after the ride.