Many motobike riders wear helmets because the inconvenience and cost of a helmet are outweighed by the fine paid if stopped at a checkpoint. In practice that means that there are certain streets with high helmet usage and others streets where fewer bother.
The cops set up in the same spots which all feature a combination of an area where stopped riders won’t obstruct traffic, an approach that offers no escape route after one spots the checkpoint, and shade for the officers. I’ve seen riders approaching a known checkpoint area reach down, take their helmet off a hook, put it on, ride past the check point area and then return the helmet to its hook.
Its what sometimes happens next that bothers me. The rider, usually male, bends over and down to look at himself in the right hand rear view mirror then uses the left hand to put his hair back into place. One can get away with riding like that because everybody one the road watches out for the idiot moto riders. Riding in traffic here is bad enough with both hands on the handlebars and one’s head on a swivel.