Fat tires and a Brooks saddle, maybe a sprung one. I went shopping on my "new" (40 yrs old) folder today. One tyre is 1.75, one is 2.00. Old sprung saddle. Soft as anything. Actually a small problem that the thing started "bouncing". You get the feeling the wheels is not round if you know what I mean. Plenty soft enough. I am planning on one or two more of this kind, no heavy forks on my bikes when it can be done this easy.