[wongarsu]

I think ebikes are limited to 25km/h (15mph) across the EU. That's a speed a commuter might reach on a regular bike on flat terrain, the motor just helps making it effortless and terrain-independent. It's still advisable to wear a helmet since cars drive faster than that.

[panzerboy]

There are eBikes which can go up to 45km/h. For those wearing a helmet is mandatory. They also have number plates and you have to have a dedicated insurance.

[Symbiote]

In British English, that's called an (electric) moped.

EU vehicle category L1e, if you want to look up the exact word in your own language.

[bambax]

Not exactly. Electric assist should stop above 25km/h for the ebike to still be considered a bicycle (and be allowed on bike lanes, etc.); but it's not hard to go above that speed when going downhill for example, and not against the law (provided you still respect the speed limit for the road you're on).

I don't think there are specific speed limits for bike lanes, or bikes, anywhere in the EU (but of course I could be wrong).

[magicalhippo]

I commute to work with my regular, non-e bicycle, sharing the road with cars. I wouldn't dream of not wearing a helmet, even at "just" 25 km/h, though for most of my commute I keep speeds above that (up to 50km/h).

[TomVDB]

Same here.

My 18 miles commute is 2 miles of sleepy suburban traffic and 16 miles on the SF Bay Trail (IOW: flat dirt track with no cars allowed.) Even if it were all dirt track, I'd still be wearing my helmet.