How long does a moto last? Probably quite a bit less than an hour. Although, the recharge time might get in the way if it's long.
I really don't mind electric bikes. They've got a place and as has been said before, I think the best place for them is the place that's not accessible right now. You simply can't have motocross with internal combustion engines in a densely-populated area. But electric bikes, which don't make noise, don't make smoke, and have a phobia of being too far-separated from the power grid, are perfect for that application. I wouldn't mind them racing internal combustion engines, either, as long as they're at equal-displacement. "Ah, but JETZ!" I hear you say, "Electric bikes don't have displacement!" You're right. Therefore, they shouldn't be racing against internal combustion engines for official scored events. There's just no standard you can point at to compare the two, unless you want to declare that all bikes must only have 35 horsepower and no more (which would be stupid).
Now that that rant is done, here's an idea. I don't know how big and unwieldy regenerative brakes have to be in order to be effective (in other words, this idea might not work) but I think that if they can get them to work on a bike, they'll massively increase battery life. Instead of spending a bunch of battery power and turning that into movement, only to burn it away with the brakes, you can keep that energy in the system by recharging the battery(ies) when braking. They're already doing that with electric cars, and diesel-electric locomotives have been using regenerative (they call it "dynamic") braking for ages. I believe the electric motor itself is used as the brake in those cases.
