If the rear Door is attached to the Tyre Carrier wouldn't it already have a locking pin at the hinge or something?
A
Locking Strut is the answer to raise and lower the Tyre in a controlled manner instead of the Cable.
I just sized these type of struts to safely lower and then raise a heavy Fire Flap Door at work that had to be done remotely by one person (the link im providing is just an example to show what they can do) They will Charge the Strut specifically to the weight you want to lift. Granted wheels will differ but it doesnt have to lift the tyre totally just take most of the weight. Im sure it wouldn't be to hard to size 3 or 4 different Struts to match with 33" 35" 37" tyres etc. OR They can supply a Strut with a Release valve so if you want you can ship a strut with a Std pressure to over do the Newton force required, then when its installed the gas pressure can be adjusted to customize the install, also it enables easy recharging! (or if you let to much gas out)
http://www.industrialgassprings.com/...ts_locking.asp
Kick ass Bar though, im kinda spewing i have the LoD now cos i did want a bar with Rear Winch, the only other option was Olympic but this Switchblade is much better! Good One