1. The problem statement, all variables and given/known data 2. Relevant equations 3. The attempt at a solution Why can't we take the moment on the left wheel? In this case, 2d(N2) - mgd = mgd + m(v^2)h/r - mgd =m(v^2)h/r ≠ 0 Shouldn't there be an anticlockwise moment about the left wheel?