Originally Posted by
marginalgains
So tell me, what is the 'best gear' to train on for endurance and or sprint?
All of them.
For sprinting, over-gear (110+) for strength, undergear (80-90) for leg speed, and everything in between for acceleration. And that's dumbing it down- a lot. If you're a beginner, just throw an 88 on there and have fun. As you get more "advanced" (or just older, as in my case), you'll want to change it up and vary your workouts, hitting different cadence ranges for specific aspects of the sprint.