This video shows how to securely install a set of 54 inch drawer slides inside your van. Using simpson strong ties, and t-nuts make a secure mount to the floor. The drawer slide are rated for over 450 pounds. The bikes are not that heavy. I do not expect to test the maximum capacity.
VADANIA Industrial Ultra Heavy Duty Drawer Slides with Lock 52″ https://amzn.to/30bAJfj I used all Vadania drawer slides in my van build. They are heavy duty, and much stronger than I actually need.
Birch Edge Banding – I used edge banding when making the pull out drawer for bike storage. I also used banding on the footrest. Edge banding is an easy way to get smooth edges, even if you are painting. https://amzn.to/3EVac4E
Edge banding trimmer – You can use a knife, or file if you do not have this trimmer. But the trimmer makes the job easy and fast! https://amzn.to/3o8SuDX