With the front triangle sharing manipulated tubing technology with the Merida, the Rockrider benefits from a stiff, accurate tracking front end. It’s from the mid-point rearward that the differences manifest themselves.
Rather than a simple beam-like swingarm compressing the shock, Decathlon has a tall, triangulated structure that resists the bending forces encountered when cornering.
This is much more effective at keeping the rear wheel following where the front has been, and stops any crab-like sideways scuttle over really lumpy terrain.
Some cheaper suspension bikes will pivot around a nylon bushing, prone to excessive wear in use. Decathlon has gone for the more expensive, and longer lasting, cartridge bearing approach. Not only does this mean the Rockrider 6.3’s pivot will stay trouble-free for longer but, from the get-go, the swingarm will have an easier time of rotating round the axis, giving a more supple ride.

The stock 450lb spring limits available travel to anyone much under 11.5 stone and spares are not easy to come by. The short shock stroke (the amount the shock compresses by) dictates a very short spring, unused by other brands. At least there’s adjustable rebound damping to calm the recoil.
The forks have a compression damping-based lockout system. Rather than being a simple mechanical on/off switch like the Merida’s, this means that there is an element of tuning available. Rotate the lever through part of its turn, and you can prevent the fork diving into its travel.

Plenty of chunky tread should give the Michelin tyres fitted traction in spades but the rubber compound has put paid to this. It may increase life expectancy, but grip plays second fiddle. Such a hard compound is less able to deform around rocks and roots on the trail, meaning — despite the large stiff knobs theoretically digging in — there is actually less in contact with the ground. You only have the hard corners and edges touching the ground.
To top it off, dirt and debris seemed to stick to the rubber more than the Merida’s.

A full 27-speed drive-train is very impressive at this price, especially on a bouncer. SRAM parts work well and closer ratios offer less pronounced jumps between gears.
Some riders don’t get on with the shifter’s profile. The thumb trigger can be easily compressed when you’re muscling the bike through technical tracks, knocking you into another gear. Moving the shifters away from the grips helps, but this is not an option for riders with small hands.

Despite having adjustable rebound damping, the shock still lets down the overall ride of the Decathlon. The compression damping (internal oil flow that regulates how fast the shock compresses) does not cope well with either rider-induced movement or large impacts.
When you are stood up, pedalling hard, the bike bobs around a lot. Not only does this rob you of energy, it’s a very disconcerting sensation.
A short top tube also compromises the bike. With bars too close to your body, it is harder to make the most of the big muscles in your lower back and buttocks, and when stood up you can bang knees on the bars. Sat down and pedalling smoothly, the bobbing motion is much less pronounced. It’s when seated, or stood up and coasting, that you can get the most from this steed.
The suspension isolates the rider from small and medium size bumps well and increases traction. This is most evident when cornering on rough ground as the wheels do not get bounced off roots and stones.

We make no bones about it, the Decathlon is great fun to rag around the woods. But the low-rent shock and slightly flexy frame quickly get out of depth when pushed hard, and the geometry of the bike encourages hooligan antics on tricky trails.
Despite an excellent level of kit and a good fork, we feel that for someone learning the ropes of mountain biking, the hardtail will be a better option.