Originally Posted by elcruxio

Depending where you're going to be riding and what gear you have, the hammock isn't necessarily any lighter or more packable than a bag, pad and a small one person tent. This is because you'll need a tarp of a decent size to protect your from rain (3X3 meters is kinda ok but I'd go with 4x4, although I wouldn't tarp it as will come clear in a second). you'll need the bug net to protect you from insects (mosquitoes and ticks in scandinavia), you'll need either a sleeping pad or an under quilt for the hammock. An under quilt is recommended since if you use a pad and you're running a bit hot you'll find yourself in a puddle of sweat since pads are pretty water proof. On top of that you'll need a sleeping bag that's slightly warmer than what you'd need in a tent since you'll be exposed to wind etc.

So in the end you'll be carrying 5 bags or so
sleeping bag,
under quilt
hammock
tarp
ropes (this includes tree huggers, other hardware like carabiner clips etc)

instead of

tent
sleeping bag
pad

Now the real reason I would not use a hammock for general wild camping in Europe or rather, the mountain regions is the weather you get sometimes. The mountain storms in the alps will rip a hammock system to shreds and they are extremely hard to predict. We're talking hurricane strength winds, vertically flying hail the size of ping pong balls etc. A good tent can shrug that stuff off, but a hammock tarp will be in real trouble since it's essentially a sail.
The storms I speak of are not that rare so riding in the alps carries a risk of seeing at least heavy winds and rain if not something of the epic proportions we faced.

In terms of what kind of temps you'll be facing, the night time temps in the mountains can go down to sub freezing. The late summer temps in the scandinavia can go down to almost sub freezing in the south and definitely sub freezing in the north.