Hi,
I for instance you had a long runway......V1 would be potentially a high speed, the only problem is that V1 cannot be greater than Vr so this would be the limited spped.
V1
VR ...................................... . (V1)
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The bracketed V1 is the speed and place where the T/O roll could be abandoned and the aircraft come safely to a stop. The VR is the actual speed and place, for this example, where the aircraft is able to rotate. In reality you would never have a decision point after T/O to abandon a roll!!! so we decrease the V1 to equal or be less than VR