I qualified my support for riding on the pavement with speed differentials. There's little doubt in my mind that the lower overall risk in many junctions comes from riders+pedestrians than riders+vehicles, especially turning trucks.

And motorbike helmets are actually very similar to cycle helmets under the shell. Biggest differences are abrasion resistance from the shell and more coverage on average, but 1/2 helmets - brain buckets - are very very similar. Indeed I see a certain percentage of London cyclists wearing helmets that would be legal on motorbikes in US states with mandatory laws.