The reservoir of the Decathlon Rockrider 6L is a Source knock-off and uses a similar slide-in fitting to seal it off, along with a lockable hose and bite valve. Not that there’s anything wrong with this because it does function in the same way, and was leak-proof throughout the test. Our only issue is having to partially dismantle the hose to route it through the elastic cords on the harness, albeit just the once.

Read more: Best hydration packs – small, medium and large backpacks

The pack feels like an old-school Camelbak – reasonable considering the £40 price tag. There’s an expandable stuff pocket for wet clothes and discarded tubes, with a big centre pocket for the reservoir and two smaller pockets on the front, one of which opens fully to reveal some excellent organisation with a number of individual pockets for tools and spares. The smaller front pocket features a waterproof zip and there are two mesh, zipped pockets on the waist belt. The bottom of the pack hides a fluoro rain cover.

The shoulder and sternum/chest straps on the Rockrider come up a little bit short, so if you’re built like a rugby player you may struggle to get this one to fit. It does feel stable, but there’s not a lot of shape to the back panel, so we found it didn’t fit snugly against the spine.

It’s hard to be critical of a pack that is 50 per cent cheaper than anything else on test, but the construction is not quite as good – the buckles and zips are particularly flimsy. That said, if you’re just starting out on your mtb odyssey, the Decathlon Rockrider 6L MTB ST900 hydration pack is the pack we’d recommend.