The previous Goodyear "Street" tire was showing cords after only 369 km (229 miles). I replaced it with a heavy-duty "electric scooter" tire (QIND Q-211). The scooter tire is a lot beefier, but the nominal size is the same, 57-203.
Initial inflation to 25 PSI caused a little tire rub (probably at the "hairs" that hang off). Lowering the pressure to 10 PSI reduced rubbing. Low tire pressure makes the contact patch wider, so more rubber is available to wear. It also improves shock absorption, but raises rolling resistance (not so important) and the risk of bottoming-out (which is hard to quantify). The operating weight of the front wheel is only 40-60 lb1 (measured with a bathroom scale) and I approach large bumps slowly, so I think low pressure is ok.
This tire was super tight to put on. I used 12" motorcycle tire levers and also zip ties to hold the seated bead against the rim while working the tire on.
For unknown reasons, after the tire change I had to adjust the V-brake left and right spring tensions a lot to prevent brake drag.
I recommend this tire for anyone who wears out multiple tires per year and is willing to deal with a tight bead and minimal clearance.
Update: The Q-211 tire lasted 3620 km. It ended with a gradual flat (first one) and some cords visible. I had periodically pumped it to 20 psi or so. At softer, more comfortable pressure, the tire and tube slowly rotate against the rim because of driving torque. This would cause the valve stem to rip out.
1 Equals 18 to 27 % of vehicle weight, depending on upper body position. Shifting the wheelchair rear wheels backward would improve the Firefly weight distribution but degrade manual wheelchair handling.
