offroad driving robot tips

I've been testing and buying wheels a lot lately but still haven't found the best configuration to drive offroad. I want my robot (30-40 kg = 60-80 lbs) to drive over ramps and uneven floors.

I use brushless hubmotors now from 10 inch (25 cm) but they are not perfect. The motors are 36V 300-350 Watt and using setting 20Amp for each motor i get enough power out of them but the wheelsize is not sufficient. My 2 motors run each 20A now and each channel has a 5A fuse which never blew so far. Battery is 36V.

Is it safe to test 30A? Will the fuse blow first or will the motorwires start melting/get warm? So far nothing gets really warm yet. I use cheap chinese hubmotors, does anybody know another country which produces those?

Did anybody test 14-16 inch hubmotors or have any good tips?

Guess 4WD (2 controllers) and 4 14-16" hubmotors will be the best but has anybody here tested such a configuration already? And are there brushless tracksystems on the market?

And if i order those 14" hubmotors what should i look for? As many poles as possible? High Amps or much Watt? I might need more batteries for that but that's another problem.

A robot which can drive on flat floors isn't hard to build but i need one who can work on rough terrain. Are there any people here who have experience in that and give me some tips which parts to use? I prefer brushless motors who are absolute silent and have rubber tires but maybe a good tracksystem will also work well. Only issue is that the tracks will damage my lawn since my robot is a lawnmower/sweepmachine.

I have some offroad tips in case you want to build an outdoor robot for uneven terrain.

-use the largest wheels you can afford/find/use....rubber tires have the best grip, air-tires also give some suspension.

-keep the center of gravity low, while braking hard or accelerating the robot will try to make a wheelie or even topple over on ramps...so keep the battery or other heavy parts as low as possible and inbetween the wheels.

-use an airfilter in case you want to force air into the robot for cooling, or place your controller so that the coolingribs (you can add them) are outside the casing.

-make sure all electric parts (motors/wires/controllers/electronics) get fresh air to cool down fast. Also protect them from dust/water.

Make sure all electronics and parts are mounted well so it can stand shocks. Also protect all wires from vibrating (fix them).

If wires go through holes make sure there are no sharp edges which can cut into the wire and cause shortcuts. Use rubber rings or so.

Try to use as less as possible connectors, soldering is better and use shrinkhose instead of tape.

Use locknuts instead of normal bolts/nuts or spring washers.

Make a solid (rubber) bumper all around the robot.

mount the battery very well so in case of a crash or toppled over robot it won't fall out/cause shortcuts.

These are just some tips which are good to know before you start designing the robot..Vibrations/dust/water/gravity are your enemies..