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T4-
World's lightest and stiffest bicycle crank arm?
The goal was to invent a bicycle crank/spider/ring
system that was comparable in weight and stiffness to the current crop of powertrains with
titanium and carbon fiber composite cranks, yet comparable to those with aluminum cranks in
price. T4 stands for Triple Triangulated
Truss Technology. State of the art CAD modeling and analysis software enabled
the creation of an
incredibly light and stiff design that would have been unfeasible to refine not
so many years ago.
The pre-production prototype T4 is heading toward testing after
extensive computer modeling, stress analysis, and many engineered improvements
over the initial design. The design is unique and truly revolutionary. There are
numerous patented innovations in the design of this product.
Not only does the T4 crank itself greatly
improve the efficiency of the powertrain, but its design enables it
to double as a chainring spider, thereby transmitting force on a more direct
path from
the pedal to the chain, and also eliminating the spider, and its associated
weight.
We are extremely excited about this product for
the following reasons.
- Current design weight (without rings) for heavy duty 175mm mountain bike
crankarms with compact 4-bolt spider is…
264 Grams *
Gram for gram, much stronger and stiffer than any other design.
Additional weight/stiffness benefits through elimination of traditional
spider
Radical appearance.
Specially designed pultruded carbon fiber spars used to reduce both weight and cost
The T4 design makes it supremely reliable. Design parameters include an endurance limit of a 200-pound
load applied 50 million times. Analysis (FEA) indicates a load capacity (yield strength)
of approximately 1700 pounds applied 2" out on the pedal.
Other expensive carbon fiber cranks have far lower load capacities*.
Lighter, stiffer, stronger, more "advanced" appearance… each by a wide margin. This concept represents
completely out-of-the-box thinking combined with solid engineering, that will enable a century
old crank arm design
to be transformed into a 21st century product.
Use the "Structural analysis" link to
view a few of the many analysis images (and stiffness information) that were generated during the
development of this technology. The "View
Prototype" link is self explanatory.
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- For comparison purposes, see: Traditional high performance carbon crankset
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