In my childhood, instead of a camera, a rubber seal of inter-panel joints was inserted into the wheel. It turned out, too, "impenetrable wheel." And I had Airless tires.
https://images.ru.prom.st/36371377_w640_h640_imag0469.jpg...
Was brewed with an inverter (2 mm electrodes), the main problem was to lay the chain line. Well and as always there is not enough time.
Варил электродом 2 мм. Проблема была с цепью и промежуточным валом. И, как всегда, мало времени.