Speaking at a press conference in Red Bull’s famous Hangar 7, KTM president Stefan Pierer just unveiled these renderings of KTM’s new Moto3 racer. As expected in the new prototype class, which replaces 125GP with 250 four-strokes next year, the bike is impressively exotic. A cast swingarm pivot connects to an impossibly dainty steel-trellis frame. The rear subframe and seat appear to be self-support carbon fiber. The front wheel is a novel large spoke/deep carbon rim design and the front brake is a tiny little single-pot radial affair. Tasty.
The self-supporting tail bolts directly to the swingarm pivot. Check out the sweep into that little stinger at the very rear.
The rear wheel appears to be much more conventional than the front (forged Marchesini?), is held on with an under-braced swingarm and clamped by a radial single-piston brake caliper. Don’t expect that Akrapovic to do much silencing.
The front wheel appears similar to a Rotobox with its very thick spokes and deep-section rim. If the wheel is constructed in a similar fashion to the Rotobox, then those spokes are hollow. That design, along with the deep rim, eliminates that traditional weakness of carbon wheels — fracturing under torsional loads — while allowing an unprecedented light weight. The hollow spokes also increase the volume of air under pressure in the tire, leading to less temperature variance and greater tire compliance. Unfortunately, the final Moto3 rules only allow magnesium or aluminum wheels, so this wheel won't make it to the track.
Like other GP classes, Moto3 requires a prototype frame, but the class cracks down on engine specs, mandating the use of a single-cylinder four-stroke with a bore of 81mm and a spec ECU. Revs are limited to 14,000rpm (which is the redline for this KTM motor) and variable valve timing or exhaust track lengths are allowed. Engines must be available for sale for 12,000 Euro or less and the inclusion of expensive performance parts is forbidden after that 12,000 Euro.
KTM is employing a radial, titanium valve arrangement and says the whole engine weighs just 55lbs.
In addition to this new Moto3 bike, Pierer again stated that KTM plans a 350 version of its 125 Duke. That model will arrive in North America in 2013, followed the next year by a tantalizingly named Moto3 350. Prototype regulations and costs mean that bike can’t share much other than inspiration with this new racer.