Would removing a heavy battery from the bike and placing in a bag that can be carried comfortably (day sack?) provide a more manageable lift-able bike mass on and off the train. granted OP will still be carrying the same mass but when more evenly distributed could it prove workable?
That's exactly what I do, for easier lifting up and down stairs, into and out of buses, trains etc. I simply place the battery into a rucksack, so center of mass is more central while moving the bike. I don't know if the Rambletta's battery is easily removable, but it should be if it isn't. I do know it can't have a BBS01B installed at some later stage if needed, if electrical assistance proves too low for the OP's health problems, should they increase, but I guess a more powerful controller could be installed and the Rambletta's battery cell pack upgraded for higher power, hub motor replaced. With it's rear hub motor, the unfolded Rambletta would still be rear heavy with battery removed, if it's removable.
@Nealh mentioned battery removal making a bike easier to handle in
post #62.
The closet I can think of is
https://wisperbikes.com/shop/e-bikes/folding-ebikes/wisper-806-folding-electric-bike-2020/ with full throttle.
Bicycle weight
375Wh: 21kg
575Wh: 22kg
700Wh: 22.5kg
Disadvantage is rack battery and the OP wanted larger wheels
Or full throttle low crossbar tailwind
https://wisperbikes.com/shop/e-bikes/step-through-ebikes/tailwind-comfort-low-crossbar/
Weight:
360Wh: 21Kg
540Wh: 22kg
Disadvantage is low crossbar rather than completely free step through
The 806 also looks rear heavy unfolded, with it's battery removed.
The OP's Crusa has the easily removable battery advantage over the Rambletta... but the Crusa, Rambletta and 806 are still rear heavy when their batteries are removed (if the Rambletta's battery can be removed). A mid-drive has the bike balance advantage, depending on where the battery is located of course.
Could the Rambletta's battery connector be replaced with an easy to disconnect/connect type, for easy removal? If the battery is behind a screwed on plate or something, removal is probably impractical. Could battery cover screws or hex bolts be replaced with tool-less knurled thumb bolts? I've never seen a Rambletta or 806 in the flesh.
The battery on my bike is easily removed after simply turning a key.
I will eventually get around to mounting my battery onto the aluminium rectangular box section I've bought, replacing the toxic chemical saturated but rot-proof pallet wood I've temporarily used (temporarily? It's been more than three years and over 4000km!) for the battery on the rear pannier rack, so that CofG while riding is closer to the seat tube. But it really isn't necessary unless I need space to stash electronics for indicators, within the rectangular box section, if I decide to install indicators.
Another advantage of a folding bike, is that it can be slightly folded in two ways or more, to snake around massive dubs of pandemic doomsday prep beans one might have stacked up high like pillars around one's home. I admit it's a niche advantage.
@Wisper Bikes and
@Woosh really should recognise the highly marketable attractive attributes of lightweight and powerful 20" wheeled mid-motored folding bikes like mine. I'm sure they could come up with prettified versions with batteries more centrally located, which would suit buyers with health issues like the OP, if they tried really hard. Very old or/and really fat buyers would also be interested. Next time I see Rapid Fatso, I'll try to sell him mine - he looks like he can afford it, getting that fat aint cheap. After shedding more than 3.5 stones, I now weigh an unfit 68kg, and in my experience of dragging 90kg trailers up steep hills with my bike, no fatso needs to buy an illegal Sur-ron to get up hills... unless they weigh substantially more than 158kg. And that was when the controller limit was just 15A - it can be 20A, but it's presently 18A on my bike to increase hill climbing speed. If they do weigh more than than 158kg/24.9 stones, they could convert a Dahon Hit and fit a smaller chainwheel than my 52T. On the other hand, the Dahon Hit's rider weight limit is only 137kg/21.6 stones... back to the drawing board.
@Katymac - I see Halfords sell Dahon HITs:
Shop the latest Commute on a fantastic bike then fold it away with ease, introducing the Dahon HIT Folding Bike. Have your bike built and delivered straight to your door. at Halfords UK
www.halfords.com
I hope Halfords haven't installed non-Dahon parts to save costs - they did with their version of the Dahon Mariner. Perhaps try one out for step overability? If it suits, maybe getting one converted with a BBS01B would be an option? There are several BBS01B owners on this forum who can suggest firmware programming tweaks. If you didn't need it to fold, the battery can be mounted centrally -
@saneagle did that with his Dahon Jetstream rear hub motor conversion some years ago, by making a fibreglass battery mounting point over the hinge. Alternatively wood can be used, like this chap:
I haven't done that, because I need my bikes to fold. Otherwise, it'll have to go on the pannier rack, and you'd need a compatible pannier rack with battery installed, if you want to use pannier bags - but then of course, the center of gravity wouldn't be near the middle of the bike. If the Halford's website is to be believed, total weight would be approximately 12kg + 5.6kg BBS01B kit +3.6kg 19.2Ah/691Wh battery = 21.2kg. Bear in mind Halfords may have copy/pasted weight of the Dahon HIT without mudguards and pannier rack from elsewhere, so definitely clarify it's weight as seen with Halfords, or whoever you're interested in buying one from.
