I have 2 delta style recumbent trikes, both homemade. One has 20" wheels and rear suspension, the other has 26" wheels which makes it a bit more tippy so it is used as a cruiser type of recumbent. I am thinking of taking the part's from the 20" version and building a tandem. The 20" wheels are very strong so will be fine for the extra weight. The rear's are each built as an axle/rim combo and the front is a 48 spoke BMX rim.