2012 Santa Cruz Superlight RXC 29er Urban Test Ride

My LBS had a medium RXC kit built up in the new Santa Cruz Superlight 29er. Took it for a spin around the SOMA district of SF. Handicap ramps with railings served as tight single track turns and switchbacks and staircases serve as technical down hills. The bike pedals great and feels sweet out of the box like most SC's. Geometry similar, as published, to the Tallboy. The short chainstays make for easy manuals and wheelie poppage. The cockpit is nice with short-ish stem ?70mm? and 685mm ish bars. The bike no longer comes with the Mavic 719rims and they have moved to the WTB Frequency 19 in order to provide tubeless compatibility. They are still laced to the ubiquitous Shimano XT hubs that Santa Cruz specs on their R kits. This wheel set doesn't feel as stiff as the Mavic rim predecessor and I am little bummed about that. The Rockshox Reba was nice and plush and the tune on the FOX Float RL pedaled nicely even when I was accelerating out of the saddle.

The Superlight is reasonably light for this value spec. SC Bike Builder app says this bike is 28lbs and that feels about right. To check rear end stiffness I did some flexing of rear wheel with my hand and the swing arm itself. Yep it's there. To check that rear end flex on while riding I whipped the back end end hard into corners and did notice some flex. What will that mean on the trail? Pavement is harder than dirt, but I only weigh 172lbs. The trade off in weight and price between the SL29er and Tallboy aluminum for sure seems to be flex which is not unexpected given the single pivot. Tallboys in C and AL are both stout bikes and feel very confident into corners and chunky trail sections.

My current bike, 26er, has a carbon rear triangle and 12x142mm through axle so I am not exactly unbiased when it comes to rear end stiffness. I don't own a 29er so perhaps the big wheel long tube flex is something I am not used to? I am very interested to see what SL's rear end flex does on the trail. I would not buy an Tallboy AL as the weight penalty and cost would lead me to just go carbon. Still, I don't want to spend $5000 on a SPXc kit. Studies have shown you need to go full bore on the Tallboy C. I'd consider buying the Superlight 29er RXC at 2350 but not until I get a chance to rail ride it. I'm stoked that the bike has Santa Cruz's well thought out snappy 29er geometry. However, I need to know that this bike is more than just an entry level 29er and could handle some aggressive trail riding. I'd like to think a wheel set upgrade and a 10mm rear axle could improve the ride greatly, but that's taking this out of the value range. FP.