I’m not exactly sure why, but a lot of African and Australian 4x4s still run on split-rim (or, more properly, retaining-rim) wheels and massively belted bias-ply tires with tubes. It might be cost, the supposed (but illusory) ease of servicing in the field, or the brute resistance of those ten-ply tires to the abuse dished out by guides and other drivers who aren’t responsible for actually buying the equipment.
A related archaic practice is the resistance of drivers on those wheels and tires to do anything remotely resembling airing down in difficult conditions. Admittedly you cannot air down a tubed tire to the same degree you can a tubeless tire, for fear of tire squirm ripping the tube’s valve off, but you can certainly vary pressure to more or less suit conditions.
Uh uh, not these drivers.
Graham Jackson and I recently got a hilarious example of this in the Moremi Game Reserve in Botswana. We were parked at a pan watching hippos, crocodiles, and a very nonchalant leopard, when an open Land Cruiser equipped with the standard lodge safari seating module arrived, with two guides and a single guest. The driver came over and asked if I had an air source, as he had a right rear tire that was worryingly low. I pulled our Troopy next to his vehicle and hooked up the ARB Twin compressor, while Graham used our gauge to check the pressure in the suspect tire. He suppressed a smile and showed me the dial, which read a full 45 psi. Dutifully we hooked up the compressor and added ten more pounds. “Okay?” asked Graham, but the guide shook his head and pointed to the barely visible bulge in the tire above the tread. So Graham hooked up the hose again and said, “Say when.” The compressor buzzed, the tire tautened, the guide watched, Graham and I traded glances. Finally the guide nodded and said, “Okay,” apparently satisfied with the appearance of the tire.
Graham quickly checked the pressure again, and handed me the gauge. I snapped a photo before putting it away, with the needle pegged above 75 psi. (At the time we were riding on 24 psi in the rear and 20 in front (in a heavily loaded Troopy), to comfortably negotiate the sandy tracks in Moremi.)
The amazing thing is that the guides get anywhere at all, although Graham has rescued some and Roseann and I have done likewise in East Africa.