I am looking into custom fabricating a bike rack for my truck, but I am not an engineer. I have a fiberglass topper on my weekend warrior truck, and I’d like to avoid using a hitch rack as I am constantly in and out of the bed cooking/camping/accessing other gear. I also don’t want to drill into the fiberglass, mount them way up high on the top of the topper (too high for overlanding), and don’t love the swing-arm hitch racks.
I’ve come up with this solution which bends 10-gauge steel sheet metal, which allows it to both mount to the inside of the truck as well as rest on sill (sandwiched between the topper and the truck).
With this design, I could: take the wheel off and utilize a fork mount, attach an off-the-shelf 1up wheel rack, DIWhy my own mount via separate hardware. I can all a strap or ‘arm’ from the roof rack to add rigidity and prevent lateral wobble.
Any engineers on this sub to give their 2 cents? TIA
by Left_Vacation_9349
2 Comments
I look forward to your final build.
I have been pondering this very solution for a long time but just kept stowing my bikes in the box upright on a rear tire pallet rack. The “rub” for me is introducing something (sturdy metal structure) between the canopy and truck box that will mar both surfaces as everything jiggles around. Perhaps a full length moulded fiberglass support trough that could become a part of the canopy might work nicely.
Also thought about re-purposing a suitable wheel cradle rack for this.
Personally I’d do some bending calculations on the mounting tab where the tray applies downward force. I would not want the bike to bend away from the car.
You could try a cantilever beam calculation using your chosen material. Estimating the force is tricky because the bike will have some dynamic load based on the road vibration and any off roading you might need to do. Google says average road vibration acceleration is about 0.2g, so you could try 1.2g.
Hopefully you don’t see any yielding in your calculation.
FEA simulation would make this extremely easy to test if you have access and know how to set it up.