A bike with pure downhill race feel from Rocky Mountain – at last! The Flatline Pro is solid, stiff, plush and inﬁnitely tunable – a downhill fettler’s dream bike.
There are options for a more freeridey set-up of the Flatline Pro to keep it versatile, and construction is bomb proof.
Rocky Mountain started with a clean slate with the Flatline Pro, working with Wade Simmons, Scott Beaumont and, until his recent departure from the company, Thomas Vanderham. The result is an entirely new bike.
Ride & handling: born for big mountains
Using the centre of its three shock mounting positions shock hole, the Flatline is a long, low bike. Our frame’s wheelbase was nearly 48in, the bottom bracket height 13.8in and the head angle a slack 63.3 degrees. Production frames will differ slightly – the head angle in the slackest setting is 64.6 degrees.
Such a long bike wasn’t going to like tight, twisty stuff, so we gave it what it wanted – steep, fast, rocky terrain, on which it bathes in glory. This bike is born for big mountain terrain. With the shock in the forward mount, handling changes dramatically – with a near-66 degree head angle and higher bottom bracket, it’s far more nimble. And we didn’t even fettle with the fork crown height.
Rocky Mountain have made a stunning bike here, although it won’t suit everyone. If fettling is your thing and you know how to get the most out of a bike, then the Flatline will serve you well. Put on a diet, it could be a World Cup race bike, or you could make it into a 6-7in travel bike park thrasher.
Frame: versatile suspension, stiff structure
Unlike the simple cantilever swingarm design of Rocky Mountain’s previous downhill frame, the RMX, the Flatline has a ‘proper’ triangulated rear end, which is substantially stiffer. It uses a single pivot based just above the bottom bracket shell, and activates the shock via a swing-link system that controls the shock’s ramp-up.
The action is very supple on smaller hits, and the ramping-up effect gained from the linkage resists harsh bottoming, but allows full travel. Out back there’s a 150mm bolt-through axle and mounts for an optional braking torsion arm.
The front end is welded from 7005 tubing. Rocky Mountain calls this its FORM tubeset, with area speciﬁc butting, wall thickness, tapers and ﬂanges to make the frame as torsionally stiff and strong as possible without adding unnecessary weight.
The Flatline has three shock positions, designed for geometry changes and for running shorter forks and shocks to alter travel and handling. It makes it possible to have a 215mm (8.5in) travel downhill beast (like ours), or spec it as a 152mm (6in) travel freeride frame. It’s a great, unique feature.
Equipment: built to last
Our top-specced Flatline Pro was dripping with quality kit built around Shimano Saint, Marzocchi 888RC3 forks and a Roco TST shock. Heavy duty RaceFace componentry and Mavic rims on WTB tyres ﬁnish the build. This kit isn’t light, but will last substantially longer than what’s on your friend’s sub-40lb downhill rig.