3T Rethinks the Crankset With Three Piece, Carbon Spindled META

3T has developed a radically different looking crankset that separates the crank arm from the rings. In a nutshell, the design accomplishes three things:

1. It reduces weight by removing material from non-stressed (ie. non-critical) areas.
2. It makes changing the rings and crank arms much easier.
3. Looks totally bad ass.

While we don’t have photos of the other side yet, both crank arms mount to the spindle/spider sub-assembly, which is carbon (yes, that would be the first-ever mass marketed carbon crankset spindle). Besides making chainring and crankarm swaps easier, it means you don’t actually need to pull the spindle from the bike to change any of it. The driveside crank arm simply mounts to the three of the chainring bolts, threaded from behind.

Current prototypes with 110BCD compact rings, bolts and BB30 bearings are weighing in altogether at just 56og, making them a clear winner in the weight wars. Official press release after the break, and we’ll get some closeup photos at Interbike in just a few more days…

PRESS RELEASE: The new crankset, dubbed META, is a radical re-think of this most fundamental component. It draws deep on 3T’s expertise in composites: even the axle is in carbon fiber.

Its form is the outcome of exhaustive research using finite-element analysis (FEA) to determine the true load points of the crank. The FEA study modelled the loads on the crank-axle-chainwheel system, and progressively eliminated all unstressed material to arrive at an idealized form. As a result, it equals the performance of the best available cranksets, and is much lighter.

The pre-production crankset 3T is showing today captures this idealized form using currently available composites manufacturing technology. It is very close to the final production item, slated for launch in 2011.

“We fully expect to produce this amazing crankset for next season,” said René Wiertz, 3T CEO. “It’s potentially 30% lighter than today’s benchmark cranksets – yet equals them in stiffness.”

Commenting on the design of META, 3T technical director Richard McAinsh said: “This is a robust proof of concept. We targeted the best-in-class products and believe that our new design achieves its design goals for stiffness and light weight.

“An important driver in reducing weight was to eliminate the bulky ‘boss’ at the center of the crank spider. We did this by separating the crank and the axle. The axle is now a separate, full-carbon sub-assembly carrying the 5 mounting points for the crank and chainrings. Our studies showed that this does not have to be heavily reinforced, and in fact the crank itself needs fixing at only 3 of the 5 mounting points. This will surprise many, but it’s very clear from the FEA analysis.

“When the crankset is built up on the bike, it’s relatively conventional in appearance. But our decision to separate the crank and the axle has some important implications for the build. The axle is the same regardless of configuration, so rings and cranks can be changed with no effect whatever on bearing pre-load. This is more flexible and makes life much easier for OEMs and amateur mechanics alike.”

META is at present undergoing thorough static and dynamic testing, and may undergo further small changes before production. But 3T’s integrated design platform, the Intelligent Production Lifecycle, assures that the product as designed is ‘buildable’ using current production techniques.

Mr Wiertz added: “For 3T’s 50th anniversary, we wanted a product at the heart of the bicycle that is as radical an advance as VENTUS was to the bike’s cockpit. META is that product.”