I used to play tennis with a foursome indoors at night on weeknights. We played from 8:30-10 PM. It was horrible trying to sleep after that. It took me hours to wind down. Riding from 6-9 PM is really not a good idea from a daily biorhythm point of view. Ya gotta do whatcha gotta do, but sleep will be a problem as you have found out. Perhaps TM after riding and before bed would help if you are dead set against a pharmaceutical solution. Something as innocuous as Benadryl antihistamine might be all you need. That is what is in many OTC sleep aids.