Dave, not knowing your history ,what are your limiters, and what races are you training for?
Assuming short course triathlon (although not my forte), for the cycling portion, you will want to concentrate on building your muscular endurance, which means riding extended intervals at a level just below to just above your lactate threshold (L4). This will only get you so far, you will need several other workouts to get faster as well (force, anaerobic endurance, power, speed skills, endurance). Base all this in a well thought out, periodized schedule, based on your primary (A) races, and you can likely achieve better results than unstructured training.
Here is a typical week for me in the early perios of the year:
Mon: rest, light running or cross training of some sort, or light ride at L1
Tue: force intervals, 6-7 minute climbs at L4, varied
Wed: speed skills or endurance ride on the trainer on the TT, or Tri bike, maybe some running
Thu: muscular endurance of L4 2x20/5 on the TT bike on the road, unless a race weekend, then endurance ride on the TT or Tri bike
Fri: recovery ride, easy L2’ish in the trainer on the Tri bike
Sat: competitive group ride of 4 hours, working L2-3, L4 and L5-6, or a race
Sun: group endurance ride, with L4 work on the climbs, 6-7 hours total, or a race