The idea here is to have two independent lift systems for each of the two spare wheels, at 400Kg each there not something you want to be trying to lift manually.
i initially thought about using telescopic hydraulic cylinders but they tend to be very large in diameter and wouldn't fit with my framework idea, so now i am looking at electric winches.
So my idea is that there is a frame mounted on the back of the truck that has a sliding frame inside it, this sliding frame is telescopic and is lifted from its lower half by the winch. The upper half of the frame acts as a guide and just follows the lower half (thats the theory anyway)
The electric winch will sit at the top of the frame with a pully on the lower frame when locked for traveling the weight will be held by a solid 20mm locking bar.
The spare wheel will be bolted to the lower half of the frame when it is lowered to the ground, it's just unbolted and rolled away.
