My bike is a bit shit really and I've enrolled in a charity 40 mile run happening in october (click on the red banner to sponsor me!). As I've been out on longer and longer runs the main challenges are sore wrists and sore arse. The bike has no suspension and combined with a stupid rake angle and no trail worth speaking of, my wrists really take a pounding (you may not be a regular reader but I broke my left wrist last Christmas).
So my solution is a gel pack for the seat (not sure it's making any difference but will keep using and see how we go) and some pipe-lagging held on with jubilee clips and electrical tape for the handlebars. The idea is to have cushioning but also extra area to change posture and keep my hands from going to sleep.
Today is my second run with this setup and so far so good:-)