This article originally appeared on BikeRadar
We put Trek's off the peg Superfly FS 9.8SL through its paces a few months ago, and were mighty impressed with what we found. But this custom iteration of the bike takes performance and personalisation to another level.
Frame and equipment: featherlight full-susser, meet kit box of delights
The 9.9 series frame has not only the carbon seatstays of the 9.8, but chainstays too, saving 100g and making this one of the lightest full suspension frames available. It's just 1650g without the Fox rear shock.
While there's a stock 9.9 XTR option, Trek offered us the chance to try its Project One custom program to create our ultimate Superfly. The process starts with choosing a huge range of paint finishes including the ultralight subtle sheen ‘Rainforest Vapor Coat' we opted for.
We picked a 'Rainforest Vapor Coat' for our Project One Superfly. Looks nice, anyhow
You can then run through various transmission options from XT to 2x11 Di2 XTR, Fox or RockShox rear shock and fork options complete with colour coded decals and wheel, cockpit, saddle and seatpost choices from Trek sub brand Bontrager. We chose superlight alloy Race XXX Lite CL wheels but shod with fat 2.35in XR2 treads and a 750mm wide carbon riser and light but cost conscious alloy finishing kit.
That still brought the complete bike in marginally under 10kg, but with more carbon trim and skinny race tyres a hardtail-challenging 9kg is certainly possible.
Ride and handling: a flexible friend, once you get the frame's measure
Despite the fact that it could have been lighter still, our build translated into blistering acceleration and as close to effortless altitude gain as you'll get with full suspension.
However, the ultralight frame and wheels are flexy under sideways loads. That means the front and rear wheels can follow different lines through random rock and root sections, and things get out of shape if you brake or accelerate hard when you're still turning. Learn to accept this and the whip from the frame as it unloads can fire you out of corners. Its snake hipped shimmy will often save it from the biggest speed-eating impacts too.
There's appreciable flex when you snap the Superfly through corners
The twang never exceeded the extra leverage and traction of our bigger bar and rubber choice either, keeping it more planted and technical trail proof than the stock 9.8.
Unlike the Cannondale Scalpel Carbon Team we tested alongside it, you can really feel the shock working to get the wheel out of the way so you're definitely getting a benefit from the rear damper. Pedal and impact response is also controlled enough to leave the rear shock in Trail mode 90 percent of the time, only flicking to Climb or Descend mode for extended climbs or descents.
The fork is easy to sync with the rest of the bike too, keeping it buoyantly balanced rather than a random ricocheting mess.