Last Friday morning the main beam on my Quest velomobile finally came apart. Now I understand why the cranks were causing so much wobbling down there. That crack has been growing for weeks, and maybe months. In this photo the left end is where it fastens to the Quest's floor, and the right end is where it attaches to the front, just above the headlight. The cranks were mounted with clamps near the center of the long straight section, where it looks like a grease smudge. Another smudge near the front of the long section is where the previous owner had the clamps. It's actually not grease, but more likely metal powder off the steel clamps that has been rubbed into the soft aluminum.
The most difficult part of dis-assembly was disconnecting the steering tiller. The Quest user manual did not have instructions for this. In my photo, the Quest is laying on its right side with the front to the left. Both front wheels have been removed and we're looking into the left front wheel well.
Getting a little closer you can see the disconnected steering control arms protruding from what I'm calling the "steering access tube" or the fiberglass tunnel providing movement for the steering control rods.
Looking straight down this left side of the "steering access tube" you can see the disconnected steering control rods. Between the front rods and the rear rods you can see the clamp which attaches to the steering tiller shaft. The clamp is compressed using a bolt that requires a 5mm allen wrench. I had to purchase the 5mm size on a 3/8" socket drive so I could attach an 18" extension to reach down there and loosen the clamp.
In this last photo you can see both sets of steering control rods, and the steering tiller clamp, in the same relative positions, laying on the ground. The two bolts on the front control rods fasten through the base of the aluminum beam. The third bolt, located at the rear of the beam, stayed where it was in the hole in the fiberglass, aft of the tiller hole. I was able to get this apart by myself but I will need a helper to put it back together.