specialized giant cube cannondale Mavic Castelli endura altura
Hydration pack guide

Hydration pack guide

You can do it, put your back into it

Hydration packs are a two-in-one cycle accessory. Not only do they carry all your equipment for the day, the reservoir inside holds a handy supply of water, accessed via a long straw while you're still on the bike.

They're a mountain bike favourite as they stay close to the body even at high speed but are equally beneficial for any riding in warmer weather or on long days out.

As the pack is worn on your back it doesn't affect the bike's handling as the mass is applied at the cranks without altering your centre of gravity. In contrast, a litre of water strapped to the frame definitely makes a difference.

Which size hydration pack should I buy?

This handy table gives you an idea of the type of luggage you can fit in a hydration pack.

Size Capacity Typical luggage Perfect fo
Kids 3 litres Phone, keys, gloves, snacks, Ben 10/Justin Bieber doll Little adventurers!
Small 3 litres Phone, keys, gloves, puncture repair kit, spare tube, first aid kit, snacks. Road cyclists, recreational cyclists, backpackers, runners
Medium 10-20 litres As above, but with room for a couple of clothing items and a good amount of food. Mountain bikers, recreational cyclists, touring cyclists
Large 21-30 litres Everything including the kitchen sink. Mountain bikers

hydration pack bladder

Reservoir Dogs

The optimal capacity

In a hydration pack, fluid is stored in a reservoir, which will vary in capacity from around one litre to three.

Obviously, the more you can carry the better, but if there's an opportunity to refill, then you can get away with a smaller reservoir.

For even more luggage, a saddle bag will fit in the same place as a seatpack and will allow you to carry spare food or a change of clothes.

bag storage graphic

Pack a punch

Room for your essentials

Hydration packs give you room for necessities such as an extra layer, tools, food or any other accessories.

Pockets are a great feature, allowing for better organisation and to keep essentials like keys close at hand.

Bear in mind that the more you pack, the more weight you've got to get up that hill!

bag graphic

Strapping structure

Harness and straps

Hydration packs are similar to a rucksack in structure and appearance, with comfortable straps for over your shoulders and a belt for around your waist.

Look for plenty of adjustment and soft lined straps if you want to use it against your bare skin.

The fit should be close but comfortable. Women's hydration packs will suit all genders of riders with their specific designs to suit shorter torsos or smaller shoulders.

bite valve graphic

Get your teeth into it

Bite valves

A bite valve is the small teat at the end of the straw, which you squeeze gently between your teeth in order to get at your water.

With a bit of trial and error, you can find a valve with the best flow rate for you.

There are also valves with locks which reduce the chance of spillages.

cleaning tools

Keep it clean

Cleanliness is next to godliness

It's so important to keep your hydration pack bladder clean.

There are specific cleaning kits available which are well worth the money, but alternatively you can visit the baby aisle of your local supermarket for small brushes and sterilising fluid.

Energy drinks are very hard to clean from bladders and can result in mould forming, so stick to water.

bag features graphic

Bells and whistles

Additional features

There are allsorts of jazzy extra features you might find on a hydration pack.

These range from key hooks, media pockets and cables, helmet attachments and security-focused zipped pockets.

You can even find whistles for attracting attention in case of an emergency.

Recommended hydration packs




Hydration pack spares

There are a varity of spares out there, including:

  • Additional bite vales
  • Tubes
  • Bladders
  • Attachments
  • Cleaning kits

There's even a clever meter which will tell you how much fluid you have left in your reservoir.