If Vmcg is greater then V1 we cannot take off.
If V1 is less then Vmcg we cannot take off.
If V1 is greater then Vmcg then V1 is reduced to Vmcg.
V1 must never exceed Vr.
The above form the basis of several questions in the JAA Performance Examination.
You will be Vmcg "limited" on hot days, high mumidity, high temperature at light weights.
Hope that helps.
(edited for spelling!)