Extract from the E-Lert Construction Manual
Figure 23 Cluster K/V
To build the frame top, rivet brackets EL020, EL021 and EL023 to the tubes. The L-profile for the backrest is added after top and bottom frame are joined. Rivet the bracket EL022 to the profile first for better access before riveting it to the tube.
Assembly Drawing EL199
The figure below shows the components which make up the drive shaft assembly. The right side in the picture is the outboard end. The shaft is supported by three ball bearings. The two sprockets are bolted to an adapter. The shape and bolt pattern of the adapters depend on the sprockets you have available. You may have to make them to fit your application. The adapters are welded to the shafts. It is important to get them on perfectly square. The short shaft EL085 is fixed while the long shaft EL121 can move vertically with the wheel through a U-joint and spline.
Figure 67 Drive Shaft Assembly
During installation, first mount the short shaft EL085 to the brackets. Align it with the front gear at the pedals so the chain runs straight. The length of the spacers EL128 and EL133 are used to keep this alignment.