The secret of the new "Airlift" system fitted to the Cloud Nine and Free Fall rucksacks is in the rubber honeycomb shoulder straps, waistband and back pads. These supposedly mould to the shape of your body, spreading the weight and allowing more of the load to be carried on the hips, where, Jansport says, it belongs, so your upper back doesn't do all the work.
The pads and straps are covered with strong breathable mesh on the inside, and the bright orange rubber lattice is visible through a PVC window running down the front of the straps. This steams up in hot weather as if to prove that all this ventilation really is keeping your shoulders dry.
They are comfortable to carry for extended periods, even when full, although the "Airlift" system only really works well with the waist strap done up. This is only possible if you have more than a 28-inch waist, which is fine for most adults but could be a problem for younger children. In any case, anyone who's ever tried to convince kids to wear a backpack on both shoulders will be all too aware of how reluctant they are to use the things properly - hence the current fashion for single strap courier bags.
A strong handle on the top of the bag means you don't always have to carry it on your back, even though the Cloud Nine's 39-litre capacity allows you to take it on the bus or tube without upsetting anybody. The one-and-a-half-inch waist straps cleverly tuck away into pockets at their base to make a lightly loaded pack less cumbersome.
The bags are extremely strong and well-made from 1,000 denier two-tone Cordura, with a 30-year warranty. Heavy duty zips divide the packs into two main compartments (both of which can be padlocked) and there are smaller pockets for everything from pens and floppy disks to mobile phones. In black and grey they are stylish enough to appeal to image-conscious teenagers, although they are rather heavy for serious outdoor pursuits.
These packs seem to have been designed for active city dwellers who need something sturdy but versatile and fashionable. They certainly fulfil this brief but at the expense of weight and cost.
JanSport Cloud Nine and Free Fall backpacks cost pound;60-pound;70. For details of stockists, tel: 0845 603 1930. The whole JanSport range can be seen on www.jansport.com