Not so long ago we all rode with glorified rucksacks strapped to our backs, but, like everything else in mountain biking, hydration packs have evolved. Of course, you can still get a basic ‘bladder and straps’ effort, but there are now packs offering myriad features and options. Here’s how to find the perfect one for you. The capacity of the pack should be your first consideration. The rise of enduro racing has brought with it a new breed of pack with an emphasis on stability rather than space. Some of these packs are even referred to as ‘harnesses’ and are designed to stay rigidly in place when the beeps start, only to afford a few sugary glugs of fuel before the long climb back up to the next stage. They’re a great option if you ride short local loops and hate wedging tubes and tools into your pockets. Handily, they don’t offer any room for your mates’ jackets, phones or hods of bricks either. So, are you looking for somewhere just to stow a bladder and car keys, or do you need a bit more space? Trail packs with 10 to 15l of storage are the next step up the ladder and are the preferred pack of the mountain biking masses, with enough storage for extra layers, food, water, tools and spares. Features such as easy-loading bladders, made-to-measure tool pockets, waterproof zips, rain covers and inbuilt emergency whistles are all well and good, but the pack won’t cut the mustard if it’s uncomfortable to wear. You don’t want it snagging on your helmet or bouncing around on the descents. A good trail pack needs to be practical too, with easily accessible tool and spares pockets – if a bodge needs bodging, you don’t want to have to drag everything out of your bag and into the rain – and tough enough to withstand crashes, brambles and being covered in mud. Some of the biggest advances in riding pack technology have come in the form of integrated safety features. These range from rear light straps and reflective detailing to straps that won’t interfere with a neck brace or body armor, and even integrated spine guards. Protecting your back is always a good idea, but the trade-o_ is usually a large foam or rubber insert that adds weight. We ask more of the humble hydration pack than any other piece of riding kit. It must do everything so well that we don’t even notice it’s there despite having crammed it full of stuff, and it’s always the very last item to be cleaned or looked after. All this use and abuse makes choosing the right one all the more important.