OK I'll say it again for all you who are still trying to figure out how to carry both....
They are NOT meant to be used together at the same time.
A quote from the Clothe the Soldier Web-site:
"
Concept of Use â “ The Small Pack System will be a basic issue to CF personnel conducting land operations. It will provide load carriage in operations where soldiers are required to wear fragmentation protection and carry combat supplies and sustainment items sufficient for up to 24 hours. In addition to the soldier's own carriage requirement, the Small Pack System will provide a means to carry the soldier's share of section/platoon weapons, amunition and mission-oriented stores."
Now for trips longer than 24hrs....that's what the rucksack is made for.
And when you finally get your new rucksack..here is the concept of Use for that:
"
Concept of Use â “ The Rucksack will be a basic issue item to dismounted CF personnel conducting land operations. It will provide the primary load carriage means in operations where soldiers are required to carry combat supplies and sustainment items for greater than 24 hours and sufficient for up to 72 hours. Additionally, the rucksack has been designed to be worn over fragmentation protection if necessary. While it will be used in conjunction with the Small Pack System and either the TV or 82 pattern webbing the Rucksack cannot be worn at the same time as the Small Pack. It will have the capacity to store the items normally carried in the Small Pack system."
So when you deploy etc, you take both..that way when you go out on a patrol or 24 hr mission, you can wear your small pack vice the rucksack.
If you're going to the field for a weekend...your small pack will do just fine.
http://www.army.forces.gc.ca/Chief_Land_Staff/Clothe_the_soldier/hab/2/273_e.asp