I agree the bike weight is almost immaterial relative to what the average rider weighs, so for riding it’s all fine, but unless you are really quite athletic there is a huge difference between lifting say 5kg off the ground and jamming it into the luggage compartment (with outstretched arms and loads of sub-optimal loading around your spine; perfect for a back injury) and doing the same with 15kg.
I can just about lift my 13.5kg MTB over a farm gate. Impossible for me with any e-bike.
The BTWIN I had were 8kg, they were pulled out of the market by Heath & Safety as they were not strong enough 
My folder is around 11kg I think a drive motor and accessories will be around 2-2.5kg plus battery.
My thinking is that a mass production mid quality ebike is probably over engineered to allow for a huge range of customers witha huge range of treatment, and avoid lots of warranty issues.
There may also be some regulations to meet.
Electrifying my bike, which may be below the pre prescribed baseline strength, will be my responsibility.
It may/will be less strong, but thus lighter. However I’ll be aware of that, and treat it accordingly. Unlike the general public on a production bike.
I can comfortably lift 15kg in ‘bike shape’ through the opening and if the battery is an additional 4kg but is separately loaded that seems acceptable.
I’m keen to do the conversion. But I just don’t have time at the moment.
I’ve priced it at around £300 for all the bits, and the bike which I’ve had for 5 years cost £40 on ebay as used, but actually not really, as there were still moulding nodules on the tyres.
Peter wrote:
but unless you are really quite athletic . . .
In my post #18 above, I mentioned my Strida folding bike – which weighs in at 10kg – which has the ability to be ‘wheeled’ when folded. I’ve found this a definite advantage at times.
Peter_G wrote:
which has the ability to be ‘wheeled’ when folded
So do Brompton and Agogs.
So do Brompton and Agogs.
This is true: But I have found transporting the Strida on undulating sidewalks, subways, and down long hotel corridors, easier than the very small wheels on the Brompton.
The Strida doesn’t fold as small and it’s ride quality is rather… let’s say and individual choice, I personally much prefer the Brompton. I propose one should try these next to each other before deceiding on one.
Inkognito wrote:
I personally much prefer the Brompton
In my original posting #18 I did write:
For serious users, the Brompton is clearly the king of the pack – for convenience in speed of folding, wheel size, folded size & gears. They are, though, not cheap: £1,000+
Boscomantico wrote:
Not my experience. My destination is almost always less than 10km from the airfield. 10km is no problem.
That’s true. Since I got my foldable „Kwiggle“ I saved taxi costs on my business trips and replaced them by the mentioned quality time …
My foldable in particular doesn‘t allow anything but shallow/short climbs. And when you take up fly&bike, you realize just how almost every airfield seems to sit on a hill….
… even for longer distances and with the mentioned hills. It depends on the transmission ratio. With the Kwiggle you have the option for 3 or 6 for your gear shift. With six it‘s going fine even when going uphill with luggage attached to the bike.
Last week I did EDFE to Frankfurt, 19 km one direction, flat.
Yesterday EDQT to Rügheim, 15 km one direction, nearly flat.
In the Beginning of the year EDDE to Erfurt (north-east), 9 km one direction, long climb uphill on the way back to the airport. No electric needed, but would have been appreciated due of the heavy luggage (I had to carry clothing, computer and the worst, some books.). 
So it’s really feasible for work and holiday purpose.
When cycling distances with the wife including luggage (backpacks), distance choice and tolerance comes down to the weakest link.
ME.
You guys are clearly keener and fitter that I.
Lol.
