I wonder why electric motorcycles haven't tried taking over support for events like Tour de France, Kona Ironman, etc. Seems like huge exposure to the right audience. I'm sure the racers would prefer quiet support vehicles without tailpipes as well.
Tour de France is too long to ride on one charge. Also the cyclist will be surprised when suddenly an electric bike comes alongside them...
I'd think that range issues could be mitigated by staging the bikes so that support riders ride in shifts. Plus, average speeds should be pretty low so EV range should be high. How far do they ride in a single stage anyway?
Quiet as they are, my Zero isn't perfectly silent. I'd think that a cyclist would be able to hear me approaching especially on an otherwise quiet course. Still, if lack of noise and cyclist surprise is a concern then small "EV chirp" style noisemakers could be added.
I've thought about volunteering with a local group of riders/first responders/HAM radio operators (jeez, there's a niche group!) which works with events such as bike races, marathons, and other event support activities. I actually haven't revisited the idea since getting the Zero, I bet they'd love to have a quiet zero emission bike to send out among cyclists and runners!