Originally Posted by
DroidTechnician
Shimano ST-EF50 Acera shifter / brake lever sets will replace the Alivio sets. Pretty much straight across. I have a set on my old Specialized RockHopper.
The ST-EF50 is designed for V-brakes, the photos show cantilevers. The only currently availible 7 speed trigger shifters are integrated with V-brake levers. This means the the OP has the option of converting the brakes to V-brakes or upgrading the gear cluster (assuming that it has a freehub and is wide enough).