From a California perspective, our Class 2 category allows for throttle-controlled ebikes, and these appear to be rather popular, in part because the pedal-assist feature of a Class 1 ebike is almost-always included in a Class 2 throttle ebike. But also – I’m speculating – that consumers like having the throttle as a backup: imagine a rider that pedals to their destination but leaves while tired and just wants to get home.
This isn’t a misplaced want, and it’s roughly analogous to the “everything car” that Americans desire but can never truly have: something that’s good for all scenarios.
A new development – and one which the legislation is only beginning to provide clarity for – is multi-class ebikes, allowing the bike to operate under different class regimes at different times. For example, an ebike which is speed limited to 20 mph (32 kph) when using the throttle but raises to 28 mph (45 kph) when pedal-driven. This would be a combination of Class 2 and Class 3, respectively.
I personally prefer at least 500 W on an ebike, which is approximately enough to hold 18 mph (30 kph) while climbing overpasses at freeway interchanges: these non-places are pedestrian and cyclist hellscapes, and riders need every advantage to assert a position.
Setting aside my complaints about American infrastructure, it’s worth clarifying that speed-limited power is most useful for hill-climbs and cargo bikes. I’m not exactly sure how often British motorway are crossed with steep overpasses, but I have to imagine the cargo bike category is ripe for expansion in the UK.
All that said, if the UK is going to update their regulations, I think a split approach can make sense: when the throttle is used, power is limited to 250 W averaged. When pedal-driven, power is limited to 500 W averaged. What averaging window to use is for them to decide, but this would account for brief bursts needed to avoid wayward obstacles and smaller hills. The public consultation does not seem to discuss raising the speed limiter for ebikes, so that’s a topic for another time.