Advantages of crank drive over hub drive.

[Jeremy]

As most ebikes are illegal anyway, it makes little difference. The main point is not to make it too obvious: A 250w label helps; always pedal; make sure your bike looks like a bike; hide it behind a large disc brake and one of those plastic shrouds that goes behind your cassette/free-wheel; try not to annoy anybody except the lycra brigade as you cruise past them up hills; don't go too fast.

Gets my vote.

Many production ebikes, approved to the supposed 250W EU limit, run at far higher power levels, because one of the acceptable test methods allows this.

As long as DIY ebikes keep a relatively low profile and we don't all start riding around as if we're on high powered mopeds I doubt anyone will be concerned. If that changes, and we get people riding at 20 to 30 mph plus without pedalling, on ebikes that look like renegades from Scrapheap Challenge, then it wouldn't surprise me if the government decided to clamp down on everyone of us.

 

[SRS]

So just out of interest, apart from it being illegal,
whats to stop people putting a bigger motor on than a 250w, say for instance a 500w?

Some great opinions above as to crank v hub

Absolutely nothing to stop you fitting a massive motor. There is however the small problem of the law, this seems to come into effect if you actually use this massive motor, particularly when giving you drive above the legal assisted limit of 15.5mph.

Makes no sense to me as one can cycle at 20mph, quite easily on a fine day. 25mph with a good tail wind and plus 40mph down a good hill.

15.5mph is to me, nonsense. I'd like to see the law relaxed to 20, 25 mph.

Law aside, I'm happy if my e-bike speed is restricted to normal cycling speeds.

At the end of the day, make your own decision, just use the bike in a considerate and safe way.