I was out on my Warrior trike on the weekend on a group ride with a group of recumbent riders. One couple brought a trike for the husband who has parkinsons disease and the wife was on a regular bicycle. Riding has proved beneficial for the husband, the trike allays any balance issues he has. They are interested in something called a 1/2 recumbent tandem. i looked up one model called a Bilinkey and it's unusual, the front is a recumbent and the rear is a regular upright bicycle. They are looking for such a beast and I was wondering if anyone here had ever built one.