Brand new e-bikes using ebikemotion system

I'm wondering whether the rear wheel can be removed and replaced by a motorless wheel in situations where assistance is not required?

This is in reference to bikes like the Ribble.

I've been looking at these too.  I'm a fairly competent rider but gravity is not my friend so a little assistance up the hills wouldn't go amiss and might mean I ride more.  What worries me isn't so much the weight - my existing bike is 10kg anyway and I have many other spare kgs to drag around - as the drag when 'not helping'.  I can skim along at 30-32kph on the flat without assistance, but say the motor is in the lowest assistance mode but not helping, is it harder to pedal than if it's turned off?

How do the modes work?  Is it a proportional amount of help, i.e. if I'm doing a gentle 100W, are the settings +25%, +50%, +100% so total 125W, 150W, 200W, or a stepped setting i.e. it'll add 50W, 150W, 250W irrespective of how much I'm trying?

certainly i think the ebikemotion system will be around for a while, there are some big players using it, or planning to. 

as devil's advocate to alansmurphy above, i'd say that it only feels like the brake has been applied because suddenly you're doing all the work yourself, not because there's any meaningful drag from the motor. the same applies to all e-bikes, especially with more powerful motors. it's not the most powerful system. anyway, i've ridden with my normal group on a number of e-road bikes and not had any problems keeping up. sometimes on a false flat with a group that's pushing on you notice that you're working harder than normal but that's mostly down to weight, not drag. and some of the ebikemotion bikes are *really* light for e-bikes. we have a ribble sle in a large in the office and it's well under 12kg.

in my experience, if you're mostly riding with a group then the lighter your e-bike the better: you'll be going faster than the assistance limit on the flat so you just need it for the hills. if you mostly ride on your own then a powerful bike works a lot better: you don't have to push on when it's flat and the hills are a piece of cake. overall, for the same effort, on your own, a heavier more powerful bike is faster.

I've ridden the Gain and the Ribble is based on the same rear wheel motor. They're goot, they're fun and they look like great road bikes, was very close to buying one for my commuter...

BUT

Despite being a low overall weight (comparitively speaking) the weight is on the back wheel. The boost you get uphill is awesome, like riding after a breakfast with Lance, but on the flat you're in trouble. As soon as you hit 15.5mph the motor cuts out and it feels like the back brake has been applied. A friend of mine has one, very strong rider but dodgy heart, and really has to consider the route before committing. Anything less than 2,000 feet of climbing on a 40-50 mile loop and he isn't really getting any help as he's effectively dragging the heavy bike around most of the ride.

As I was looking for a commuter with some steep climbs and flatter roads (only 12 or so miles each way), going for a hybrid or off-road bike with a Bosch seemed the better option. I can load it up with saddle bags, hit some off road sections and treat it a bit more roughly as well as fitting huge tyres for the winter.

Before parting with the cash, have an extended test ride.