Drive system with contoured cavity

An improved drive system for a personal vehicle having a frame, front wheel, rear wheel, drive axle, drive linkage attaching said drive axle to said rear wheel, and crank arm attached to said drive axle comprising:

• a crank arm having a contact member;
• a cavity defined in said pedal for receiving said contact member;
• and,
• a major arch defined in said cavity assisting in preventing said crank arm from counter-rotating;
• and
• a minor arch defined in said cavity disposed adjacent to said major arch wherein said major arch is forward said minor arch.

A drive system for a vehicle having a frame, drive axle, crank arm attached to the drive axle and a drive linkage connecting the drive axle to a wheel so that the wheel rotates when the drive axle rotates comprising:

• a pedal pivotally attached to the frame forward said drive axle;
• a cavity defined in said pedal having a major arch and a minor arch;
• a roller attached to a distal end of the crank arm wherein said roller is received in said cavity;
• and,
• whereas when a downward force is applied to said pedal when said pedal is in its upward most position, said roller contacts said major arch causing said crank arm to rotate while assisting in preventing the crank arm from counter rotating.