Thule’s Rail 4 is a neatly designed, great-quality hip pack that comes with a 1.5-litre HydraPak bladder with a ReTrakt hose system. It’s one of the smartest hydration pack straw designs on the market.
The ReTrakt system attaches a 160mm magnet within a sleeve to the hose, which attaches to an even longer (230mm) magnetic strip on the bag.
Its wrap-style hip belt can be tensioned from either side, thanks to adjustment on both the male and female clips. The straps attach to the pack’s main back panel, feature small side pockets, and have generous padding throughout.
On the front of the pack is a Velcro flap pocket and a dedicated zippered and lined sleeve for a phone. The mesh side pockets can be used to stow small essentials such as a multi-tool.
A generously padded yellow-coloured main compartment opens wide, giving access to the supplied 1.5-litre bladder.
Thule Rail 4 performance
The ReTrakt hose is reliable and easy to store. It’s virtually impossible for it to bounce loose, a problem some other bags’ straws suffer from.
Inside the main compartment is space for a thin jacket and tools, as long as the bladder isn’t at maximum capacity.
The stretch-mesh strap and Velcro-fastening hip belt with webbing clip strap make the pack close-fitting and comfortable to wear. However, riders with narrower hips might struggle to adequately tension the straps to fully secure it in place. This issue is common to many packs.
Once full up, the pack’s centre of gravity is shifted further away from your body, which caused some bouncing movement over rougher steps and drops, but not enough to be a major problem, and wasn’t noticeable on flowier trails. The pack never rotated around my hips.
I like the dedicated phone compartment, but the length of the zip limited what I could fit in there, despite the internal size of the pocket being large.
The front pocket was easy to open and reach without removing or twisting the pack, even when on the move.
Thule Rail 4 bottom line
The Thule Rail is good value given its robust build quality and detailed features. Thanks to impressive comfort levels and a number of storage options, it’s functional and easy to use.
On very rough trails, or when it was at full capacity, it was slightly unstable. However, I can forgive it for this given the opulent padding and impressive ReTrakt straw and bladder system.
How we tested
We tested five hip packs designed to make life easier on the bike. We filled them with our usual all-day ride stuff, including tubes, pumps, snacks, tools and emergency supplies, and wore them while riding a wide variety of terrain in Scotland’s Tweed Valley.
This included trails with high-speed sections and super-technical features, to see whether they stayed put or bounced around and became uncomfortable. We also wore them for some daily rides and commutes, to see how user-friendly they are and whether they make our list of the best hip packs.
Packs on test
|Price||br_price, 5, 3, Price, AUD $169.00GBP £90.00USD $100.00|
|Weight||br_weight, 5, 6, Weight, 523g – 382g w/o bladder, Array, g|
|Brand||br_brand, 5, 10, Brand, Thule|
|Features||br_Features, 11, 0, Features, 1.5L HydraPak Reservoir included|
|Capacity||br_capacity, 11, 0, Capacity, 4l, Array, l|