Wit the bikes swapped over, we head out on the same loop again, this time on the 29in Big Nine 100. Whereas the Big Seven was snappy off the line, the 29er takes a couple more pedal strokes to get up to speed. That said, once it's up there, it's easy to keep the big wheels rolling, allowing us to cover ground with ease. The fire road is at times a little rough, and the bigger wheels roll over the imperfections so we barely notice them.
Flex appeal
As the trail starts to rise we lock the fork out again and push hard on the pedals. The slightly bigger wheel gives us more flex, both at the front and the back of the bike. The frame's threaded bottom bracket doesn't have the same stiffness as a press-fit unit, as there's less area onto which to weld the rest of the tubes, and the fork's longer legs and spindly quick release mean the front wheel twists in the fork. Once again, Shimano's Alivio and Altus groupset performs well - on the flat we can maintain higher speeds, while the 22-tooth granny ring lets us spin up steeper climbs.
Even though we've only covered a kilometre so far, the difference in frame sizes is apparent. Both bikes are 17in (Medium), but the Big Nine feels like a bigger bike, largely thanks to the seat tube being 8mm longer and the headtube 5mm longer on the 29er. Conversely, the Big Nine is 5mm shorter in the toptube. Cliches aside, it does feel like you're sitting atop the 29er, whereas you feel much lower to the ground on the 650b-wheeled Big Seven.
Getting to grip
Heading into the singletrack the Big Nine's bigger wheels give us a touch more grip, now that we've sorted tyre pressures across the bikes. We feel more confident on looser sections of trail, and it feels like we're less likely to understeer as we head into corners. This allows us to carry more speed through the trail, without it becoming a white knuckle ride.
With a higher centre of gravity the Big Nine is a bit more ponderous in the woods, making it slightly less willing to snap around the trees. The bigger wheels roll over the roots a touch better, despite the hard compound tyres wanting to slip and slide, but the chainstays - 15mm longer than on the Big Seven - mean the bike is less inclined to lift its front wheel over bigger fallen branches.
Both bikes come with Tektro's Auriga brakes, with 180/160mm rotors. Stopping power from the basic brakes isn't up there with the best, but the lever is long and comfortable, so we rarely asked for more. The lever has a basic reach adjust, which is a nice touch at this price point, although we would like it to come closer to the bars.
Frame detailing across both of the bikes is good. There are rack mounts, should the Big Nine/Big Seven have a more urban life, and the exterior cable routing, while not as smooth as hidden routing, gives easy access for maintenance.
Not a super inspiring ride, but more confident andcapable in most situations than its 650b companion.
FRAME Big Nine TFS
FORK SR 29 XCM HLO, 100mm
WHEELS Alloy Disc hubs, Merida Nine Comp D rims
TYRES Merida Race, 29x2.1in
CRANKS SR XCM, 44/32/22
GEARS Shimano Altus nine-speed shifters, Alivio mech (R)
BRAKES Tektro Auriga, 180/160mm rotors
BAR & STEM Merida Comp OS 680
SEATPOST Merida Comp 27.2
SADDLE Merida Sport 5
SIZES 15, 17, (tested), 19, 21in
WEIGHT 13.4kg (29.5lb)