Hi Frank,
Busy weekend and just got to your post. The bench height of 900 is not absolute but optimal for a few reasons. Wife is only 5' 2", sorry 5' 2.5" :-) Very important that 1/2 inch. Not a problem for me. The height is compounded a bit by having to lean in as the bench edge will be in a bit back from absolute trailer rear edge.
The second part of this is looks. I would like it to be squat not high. I am not intending going anywhere that a normal car can't get (unless I am being ultra careful). My son has a 4WD so some very strict rule setting will go on if he borrows it. The axle will be a 4" drop axle lowering it even more so ground clearance will be a factor.
The wheels (205/60R15) was to get a very similar look to the tow vehicle. It is intended to be a 1987 Citroén CX. The Citroén has a PCD of 98 so there is no way I am going to get a trailer hub that I can use the Citroén's spare with, hence the need for a spare. My other car has 19" rims so not even going to consider matching them. I could go for a 14" rim and still retain the look really. Too skinny with the tyres will take away from the look though. A 195/75R14 is not that different in overall size. There is not a lot of difference when you look at a variety of them.
205/60/R15
Diameter = 24.7"Width = 8.07"Wheel = 15"Sidewall = 4.84"Circumference = 77.5"Revs/Mile = 817.4
205/60/R14
Diameter = 23.7"Width = 8.07"Wheel = 14"Sidewall = 4.84"Circumference = 74.4"Revs/Mile = 851.9
205/75/R14
Diameter = 26.1"Width = 8.07"Wheel = 14"Sidewall = 6.05"Circumference = 82"Revs/Mile = 772.9
205/70/R14
Diameter = 25.3"Width = 8.07"Wheel = 14"Sidewall = 5.65"Circumference = 79.4"Revs/Mile = 797.6
195/75/R14
Diameter = 25.5"Width = 7.68"Wheel = 14"Sidewall = 5.76"Circumference = 80.1"Revs/Mile = 790.8
195/70/R14
Diameter = 24.7"Width = 7.68"Wheel = 14"Sidewall = 5.37"Circumference = 77.7"Revs/Mile = 815.4
185/70/R14
Diameter = 24.2"Width = 7.28"Wheel = 14"Sidewall = 5.1"Circumference = 76"Revs/Mile = 833.9
At a push I could get away with the 185/70R14 - it might not take the bumps as well that's all but better than the 205. Time to visit some build journals to have a look.
I have never had a puncture on my box trailer but I know what will happen when I don't have it with me. Thinking of putting on 4 corner stands so I can get away without carrying a jack but I will have to price a jack first just in case there is a HUGE cost difference. I wonder how many people out there who have a spare for their trailer carry a jack or even a tyre lever so they can change it if they get a flat?
I have found a bloke who can build me a water tank that will sit over the spring axle. That is why I am using a drop axle. To give me some vertical space but have the trailer sit lower. The tank will have enough space for vertical and lateral movement with a 50-75mm piece joining two drop down tanks on either side. Should give me perfect balance so not adding any tongue weight when full empty or whatever - or minimal weight change really as you will get a bit of splash from one side to the other. I could add two tanks equal distance back from the axle for the same effect but not quite as elegant and will actually cost more than a custom tank.
Keep the comments coming - it makes us think. Good all round.
Laurie