Avid bikers riding indoors.
People ride bikes indoors.
Saying someone is a biker and they are riding is the same as saying they ride bikes.
exists e1 s1 x1 x2 x3.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_ride(e1) & n_indoor(x3) & (x1 = x2) & n_biker(x1) & a_avid(s1) & Theme(s1,x1))
exists e1 x1 x2 x3.(Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & Time(x2,x3) & n_indoor(x3) & n_bike(x2) & n_people(x1))