Finnish firm, RMK, debuts electric motorcycle with hubless rear wheel

robmack

robmack

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Finnish manufacturer, RMK, is taking orders for a new electric motorcycle, the E2, featuring a hubless rear wheel drive. The bike develops 50KW (67HP) and 320 Nm (236 ft/lbs) of torque. Range on the bike is estimated at 200 km - 300 km (124 miles - 186 miles). Priced at Euro 24,900 (CAD $37,300) :eek:

https://rmkvehicles.com/

Netti_01.jpg
 
so, to that funny looking rear wheel
3 fat yellow wires?
3 phase AC motor?
DC motor would not need 3 conductors

and looks like a brake line too
must be shoes in there?
can't see how a disk would be in there

only advantage I really see of that rear drive setup
is no chain/belt/shaft FD
but it looks like a marketing thing to me
put a regular wheel and FD on there
prolly knock 10K off the price
 
Butt fugly.
 
I don't understand why electric bike manufactures go out of their way to REDESIGN the entire bike...I mean why?? Look at tesla... yes the got an electic motor, but they did not change the way cars look in a radical way ( forget modelX)

I'm all for futuristic e bikes...but please leave the chassis, frame,swing arm, shocks, brakes, aero package alone!
 
I like the motor in the rear wheel and think the orange HV phase leads look kinda cool. It's unfortunate that the frame and rear suspension look Canadian Tire-grade.
 
Blackfin said:
I like the motor in the rear wheel and think the orange HV phase leads look kinda cool. It's unfortunate that the frame and rear suspension look Canadian Tire-grade.
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From their website "Unsprung mass is comparable to a conventional setup but rotational mass is considerably smaller. Tire changes easily done with conventional tools."

WTF? That seems very unlikely with this design. Maybe by comparable they mean "less than double". That bearing will be friggin heavy not to mention the metal motor windings. Similarly, with the outer bearing race that close to the perimeter rotational inertia should be much worse. It only makes sense if they are playing with unobtanium for marketing purposes like nanotube wiring and carbon races and have no intention of those surviving to the final vehicle (if it ever actual happens).
 
Like the Harley Livewire I just do not see these selling. The price point is ridiculously high, especially when you get get super bikes for that amount or fully decked out adventure bikes from BMW with every bell and whistle and the ability to refuel in minutes opposed to hours.

These are crazy E-Bikes with a ton of power and more range, but they do not have enough range and can not be charged quick enough for anything other then daily commuting. And if all you can do is a daily commute why spend over $30,000 when you get get E-bikes for a couple thousand?
 
Hmmm, hubless rear wheel, looks cool but not practical. Get a bit of grit and mud accumulated over time, and I'm sure it will seize. Doubt that dependable technology is there, and that would include the electric motor and battery. Being the first kid on the block to get one these, these days, means you end up as the guinea pig. And if I'm being used for research I want the bike at less than half of the advertised price.
 
JavaFan said:
maybe so, but what's the hydraulic reservoirs on the bars for?
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The right side lever is for the conventional front brake. The left side lever controls the amount of regen braking on the rear wheel.

Sent from my SM-A530W using Tapatalk
 
Iceman said:
The right side lever is for the conventional front brake. The left side lever controls the amount of regen braking on the rear wheel.

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I'll buy that...but why is it hydraulic?
 
JavaFan said:
I'll buy that...but why is it hydraulic?
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That I have no idea, just quoting the literature lol.
My mind thinks there may be a small hidden brake disc mounted somewhere in there, just not in a conventional location.
I admit though, most of this tech is beyond my current understanding. I need more info and specs to "get it".

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Iceman said:
That I have no idea, just quoting the literature lol.
My mind thinks there may be a small hidden brake disc mounted somewhere in there, just not in a conventional location.
I admit though, most of this tech is beyond my current understanding. I need more info and specs to "get it".

Sent from my SM-A530W using Tapatalk
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yup, I agree

most of the rear braking effort will be from the motor on regen
but at slow speeds, like a parking lot, that ain't gonna do much
and there are times, and I'm sure it's also a safety requirement
where the rider needs the ability to lock the rear wheel, regen can't do that
so yeah, there must be some sort of hydraulically actuated brake in there
 
JavaFan said:
where the rider needs the ability to lock the rear wheel, regen can't do that
so yeah, there must be some sort of hydraulically actuated brake in there
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The electric motor could easily lock the rear wheel. Yes, technically not with regen, but it is trivially simple to power the motor in the opposite direction to provide braking force that exceeds the available grip. As a simple approach, rapidly switching from backwards to forwards keeps the wheel locked while needing no feedback, sensors or modulating power. Obviously at the expense of range.
 
GreyGhost said:
The electric motor could easily lock the rear wheel. Yes, technically not with regen, but it is trivially simple to power the motor in the opposite direction to provide braking force that exceeds the available grip. As a simple approach, rapidly switching from backwards to forwards keeps the wheel locked while needing no feedback, sensors or modulating power. Obviously at the expense of range.
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yes. I'm familiar with how this is done ~> electric mining shovels do this
it requires extremely accurate speed detection in both directions
and processing hardware/software to very quickly apply torque in the proper direction

at $37,000, yeah, that tech might be in there, but I doubt it (waste of battery energy)
but I still think it's got a mechanical rear brake in there
this would be why there is a master cylinder and brake line
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