An investigation of the effects of a finite confining potential on the sub-band energies and electron-bulk-polar-optical-phonon scattering rates is presented within the effective-mass approximation for quasi-one-dimensional cylindrical quantum wires. Numerical results are given for the GaAs/AlGaAs system where a lowering of both the confined energies and electron-bulk-polar-optical-phonon scattering rates with respect to the widely used infinite-confining-potential approximation is found.