From Bike Rumor: "Scott Bicycles has unveiled what is likely the lightest full carbon production mountain bike frame, the 2011 Scale 899.Weighing in at a claimed maximum of 899 grams, the new bike took what they learned from their original Scale (which came in at 970g) and not only made it lighter, but refined the geometry, layout and feel of the bike, too.
First off, the geometry. The 899 has a 20mm longer top tube, a 5mm taller headtube and a 10mm lower bottom bracket height. The headtube is now tapered to 1.5″ at the bottom, so it’ll run the latest lightweight forks, too. On this model, the new tapered Rockshox World Cup SID XX handles front suspension.
The main way Scott dropped weight on the new 899 is by moving from tube-to-tube construction on the old model to increased use of their IMP (Integrated Molding Process) construction technique.
The downtube remains very wide all the way from the headtube to the BB30 bottom bracket. Several changes in the bottom bracket area further improved stiffness and performance while dropping weight. First, the seat tube flares out, which improved stress resistance in Scott’s FEA testing and allowed them to use less material with the wider design. Next, they removed the alloy threaded inserts and used press fit bearings, keeping the frame all carbon. Lastly, the wide downtube reduced frame stresses better than the narrower tube on the prior model.
At the top of the seat tube, they used this trick seat bolt design to replace the clamp. Even the lightest collars/bolts are about 16g, and this design is 5g, saving them 11g.
With a 200kg load on the seatpost (and when you hit a bump, you’re putting far more than that amount on your bike, even if you’re a lightweight), Scott measures rear axle deformation (ie. vertical movement) at 4.66mm, which is about 1mm more than the prior Scale. The Tubular Structure assembly is also 25g lighter and 10% more laterally rigid, according to Scott.
Further weight was removed via the direct mount brake system in the rear, and by going to internal cable routing, they removed all the alloy guides, screws and parts that added up to about 47g. The plastic cable guide on the bottom bracket’s exterior and four bottle cage bolts only contribute 11g for a savings of 36g from previous Scale.
The bike shown here was for demo purposes and not built to actual spec. The actual production Scale 899 will be spec’d with DT Swixx XCR 100 carbon fork, DT Swiss hubs and carbon rims, Selle Italia saddle and Scott Pilot SL handlebar and stem. All other spec is as shown, except the tires will be Furious Freds, not Rocket Rons.
MSRP TBD, and there will be three models using this top of the line frame with Scott’s new HMX Net carbon fiber, called the Scale 899, Scale Premium (with 2011 XTR) and Scale RC. Below that, there’s the Scale 10, 20 and 30 that get the HMF Net carbon fiber which is slightly heavier and less stiff (just slightly). Lastly, there will be a Scale 70 with a lightweight alloy frame.
Want more? The 29er version gets unveiled this weekend…which is called the 949. Guess what it weighs?"