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MARS projects - VFS - Mounting the foamshell
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Mounting the foamshell on the LFWD

Because unmounted foam is floppy, the mounting system is the place where one regains the stiffness and stability. Because the bike is made to be stiff, it also makes a terrific place for attachments.

The most important mount is the one supporting the nose. This shows the Y-shape that is attached to the boom. The pads hold up the nose and also spread the nose apart an appropriate distance. If the Y is too narrow, the shell will move left or right. Too wide, and the shell will be spread too wide and not have enough vertical support. The pads spread out the load so the shell doesn’t have a bump on the outside surface.

This shows a view of the individual Y-structures. The rod is a carbon tube. The pads are made from scrap foam. There is a wooden plug at the pad end of the tube so it doesn’t cut into the foam. This plug is also a way to fine-tune the nose height.

The second most important mounts are the ones off the seat back. The seat is a stiff structure, making an ideal mounting location. This is where the shell is aligned in relation to the nose. Here the mounts need to be adjusted forward/backward, up/down, and in/out (shell width). The photo shows the left side bracket. A wooden block is glued to the shell, and an angle bracket is attached to the wood with wood screws. The surface area of the wood makes a decent glue surface for the foam.

This shows the two pieces of the bracket. The angled piece with slots gives the up/down adjustment. The other piece can be adjusted forward/backward and in/out (C-clamped), and is bolted to the angled bracket after the shell is properly adjusted. This piece has a conversion from the flat sheet metal to a plug. The end is plugged into the aluminum tube that is attached to the seat back to simplify removal of the shell.

Another important attachment point is from the bottom bracket to the bottom of the nose. This prevents the nose from swinging left/right from side winds causing the shoes to drag on the inside of the shell. It consists of a carbon tube which slips into a tube that is carboned to the underside of the bottom bracket.

At the bottom of the nose is a bracket to which the carbon tube is clamped.

Another very stable place for attachments is the bike frame below the seat. This ties in the bottom of the shell very securely. Two machine screws are permanently screwed into the frame tube. Wing nuts hold the foam to the frame.

The last mount is at the end of the tail. The tail essentially uses the luggage rack for its stability. See Tail section for details. Between the two Y-supports, two seat supports, bottom bracket-to-bottom of nose support, bike frame, and tail-to-luggage rack support, this once floppy shell becomes surprisingly stiff and stable.

To remove the main shell (once the Turtledeck and Tail are removed), unclamp and pull the bottom of the shell down to disengage the lower bracket, remove the two bike frame wing nuts, and spread the bottom of the shell apart. Then unplug the two seat mounts and slide the shell forward off the bike.

Next section: Front mount / foot clearance issues