WHY THIS HAPPENS
Repeated-sprint ability (RSA) below group average — you can't absorb surges
Anaerobic capacity (W') too small to bridge gaps when the group accelerates
Poor positioning — burning watts fighting the wind instead of drafting
Pacing on climbs — going into the red too early, dropping off the back on the second half
Nutrition timing — 90 min in with no carbs is the classic drop zone
Aerobic base insufficient for the duration of the ride
Bike position or equipment inefficiency — 20+ watts lost to drag or rolling resistance