Versatile Articulating Rotation-Stopper

grabcad

The downtube is the most reliable frame member to securely attach the motor without having to contend with numerous rear-suspension-design restrictions. What's unique to this entry from others is the use of the bolt lug of the motor-casing as anchor pivot. Also, the tie is simply made out of regular brake cable or a thinner shifter cable! When the tubular downtube has bent end section, the seated articulating member will be angled so to center the four contact spots at the mating surfaces. Then one brake cable (or shifter cable) is looped to firmly secure the motor. The cable is fastened with plastic/silicon-rubber tubing/sheath to prevent direct contact to the paint. (Reflective translucent sheath can camouflage the cable to the painted/lacquered frame.) Aside from versatility, the advantages are: 1) No existing part modification, replacement or discarding on the Sunstar motor. 2) Very lightweight assembly. (ABS and steel parts: 53g, ABS & titanium parts: 45g, possible FEA enhanced final weight: >30g) 3) Mounting closest to the anchorage, hence: a) virtually no torsional/bending deflection inherent to longer reinforced parts. b) lesser material required. c) virtually no part wear or fatigue stress. d) lessened vibration and elastic deformation. 4) Neat and compact form factor as it is tucked between the downtube and the motor. 5) More versatile wrap-around position of the cables, as compared to hose clamps and metal braces/clips. 6) No significant stress imparted on the bicycle frame or its crank shell and virtually no significant lateral force imparted on the paint to cause peeling/scratch. 7) Due to compactness, parts are smaller, cheaper and quicker to produce. 8) Very ergonomic and aesthetically pleasing. Parts are made up of durable injection-molded plastics. preferably ABS, except the tensioner, pulley, cable clamp and set screw. In this way, paint-protection padding is unnecessary. Also, parts are quicker to mass-produce and are more lightweight yet maintaining the complexity to be universally adaptable to modern bike frames. UPDATE: upgraded version of ABS plastic components finally uploaded! Filename: Rotation-Stopper Assembly-FINAL ENHANCED ASSY.stp (housekeeping: old STL files deleted and replaced by one step file of previous preliminary models as reference)