Due to popular demand the option to model a Pinion gearbox has been added to BikeCAD version 11.7.
To add a gearbox, open the Drivetrain dialog box, select the Gearbox tab and check the box labelled Include. The Pinion gearbox will appear in place of the conventional bottom bracket. All dimensions that used to relate to the center of the bottom bracket will now reference the crank shaft of the Pinion gearbox. Because Pinion gearboxes are designed to use the standard Pinion gearbox bridge, all the geometry of the gearbox is preestablished. The only dimension you may want to adjust is the angle of the gearbox which you can change to optimize the attachment of the chain stays, seat tube and down tube. Be aware that you can also apply an offset dimension to any of these tubes, so they do not necessarily have to line up with the center of the crank spindle.
If you choose to hide the gearbox, the Pinion bridge will remain visible as it is considered part of the frame.