Between 2011 July and 2011 September, my partner and I did a 3 300km bicycle tour of southern France. The below is a review of products that we used during that tour.
The ZPacks Zero backpack is made from 50g/square meter cuben fiber. I had the company add a water sleeve and shock cord lashing and reduce the size a bit (see below). The total weight was 95g. The water sleeve was great to have despite the additional 9g. My 2,5 liter bag was a tight fit when I put over 2 liters in it, but with enough patience I could always squeeze it in. I eventually sent the shock cord back to the US -- I rarely used it. Unfortunately, I didn't think to seam seal my pack before I left, so it was nearly useless in a hard rain. The straps were on-the-fly adjustable and the padding was excellent. I didn't have ZPacks add any support straps
Though it is not such a fan of chafing, cuben fiber, a polyethylene filament buttressed by cross fibers of other esters (Kevlar, Vectran, Zylon, carbon), is very tough. This is the material of choice for the weight weenie with an unlimited budget, a limited conscience (who knows the environmental consequences of a material like this?), and/or a need to save his/her back from undue stress. I prefer to think myself in the latter-most category but the middle-most is more like it. Certainly not the former-most. Cuben fiber is water proof (but needs to be seam sealed) and not breathable. This made for a sweaty back, but even my ultra-breathable REI Stoke backpack, which has a breathless combination of breathable design and material, isn't much better.
I requested that ZPacks make the pack a bit less tall than the standard model. This was to avoid the backpack hitting the back of my helmet, an annoyance similar in effect to severe tooth pain or kidney stones, and because I did not need the extra room. Still, this pack held 24 liters, of which I used 16 liters for base gear. Even with 2 liters of water and a liter of food I had plenty of room left over. The material color I chose -- white -- was actually semi-translucent. This made finding gear much easier. And it made the backpack a hot-house. Any meltables melted. No chocolate in this bag!
ZPacks was a champ to deal with. They customized the pack and, when the seamstress made a small error, offered to make another one. I felt guilty enough as it was using cuben fiber, so I told them not to bother and, anyway, I have yet to find the error. Whatever the error, it certainly didn't affect the functioning or look of the pack.
At no extra charge and despite it being my fault, ZPacks expedited shipping so that it would arrive before we flew out. It arrived the day before we jetted off, which could have been disastrous if my little experiment with touring by back-pack hadn't worked. It did work, though, and the incredibly light weight of cuben fiber coupled with the flexibility and excellent workmanship of ZPacks made it so.
