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Answered The future of ebikes?

Beekeeper

🍯Honey Monster🍯
Aug 6, 2019
1,745
2,194
Surrey hills
The new Harley Davidson pedelec has a mid-mounted gear box.

Is this the future?

Will we start to see the gradual disappearance of derailleurs?

A1F9B016-F9CF-4D0C-A744-774CE2818FAC.jpeg
 

bissona

Active member
Patreon
Oct 14, 2018
137
106
Guernsey
Undoubtedly. Mass centralisation and less exposure to dirt/damage. Good to see that has a gates belt drive too, I love the one on my Cannondale.

That said, the HD pictured above has to be one of the least attractive ebikes ever made, so maybe let's wait until someone sensible has designed one!
 

Mcharza

E*POWAH BOSS
Aug 10, 2018
2,499
4,723
Helsinki, Finland

Fivetones

E*POWAH Master
Patreon
Feb 11, 2019
898
904
Cheshire
I think a combined CVT type box (not discreet gearbox as too heavy) combined with the motor as that has transfer gears too so these could be eliminated. If this is going to fly it needs to be lighter than motor+derailleur or if weight penalty be much more robust. Electronically controlled semi-auto would also be possible to keep the motor in optimum torque and thereby reducing battery use might also be a possibility (so smaller battery could reduce weight).
 

Rusty

E*POWAH BOSS
Jul 17, 2019
1,513
1,673
New Zealand
Looking at past endeavors and various patents i have come across I am thinking perhaps the way Honda went about it with Minnaars RN-01 might be the go .... Internal Derailleur. That system was IMHO brilliant - keeping those moving parts clean and protected.

Looking at that Hardly Ferguson design concept - could be tidied up some, however being a hard-tail things are much easier. Add rear suspension then you have to allow space for a shock, swing-arm pivot and most importantly, add a chain tensioner as unless you can design a system with the pivot point exactly at the centre of the front sprocket you are going to have chain tension dynamics come into play.

Having looked inside a couple old motorcycle road-racer gearboxes (Honda 12sp & Suzuki 14 sp) I am thinking that even though metallurgy has come a long way there would be too much weight and more importantly too much drag. However, as @Fivetones (not a bassist are you?) says CVT could be an option. Yes there would be drag but having seen a simple design a few years ago with stepped cones, a belt and a sliding mechanism to move the belt up or down
similar to image below, but would need ramps between the levels.
images

With something like this the cones can be hollow with just spiders back to the rotating shaft.
That would keep weight down and if designed correctly should I hope minimise drag.


@ggx - Maybe Shimano E9000 :alien::alien::alien:
I doubt it very much. Rumour has it as being smaller, lighter, more torque and less battery drain.
Of course that could just be the instructions the engineers were given as a brief.

@bissona - Good to see that has a gates belt drive too, I love the one on my Cannondale.
Put one on my SS and found myself stripping teeth. Not quite the best for clydesdales like me. However, with a motor and gearbox it could definitely be a viable option.
 
Last edited:

Slowroller

Well-known member
Founding Member
Jan 15, 2018
494
496
Wyoming
If the can get the weight of a motor and gearbox/cvt within a lb or so of motor + der + cassette + shifter and cables, which they should be close to, it'll be a no brainer. You'd end up with better weight distribution, a stronger wheel, no fragile der or hanger, a better chainline, more uniform suspension kinematics, stronger and longer wearing chain and cogs. Or belt.
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,362
8,589
Lincolnshire, UK
The future may have already arrived with a breakthrough in the energy density of lithium-ion batteries (the sort emtbs use).

Currently the energy density of these batteries is about 250whr/kg, well the sort that Tesla use anyway. Tesla believe that they can push that to 330whr/kg. Meanwhile the US Dept of Energy are funding a programme that will lead to 500whr/kg. If that is achievable then your bike may go twice as far as it can now! :)

But in Apr'19, Inolith - a small start up in Switzerland, claimed to have achieved 1000whr/kg. So not only will the battery propel your bike twice as far, it will weigh half as much! :love:

Inolith are claiming that they need 3-5 years to get to a commercial stage, so late 2022 at the earliest. But I suspect that cars and mobile phones will be in the queue before emtbs! :(

Oh and a nice PS: The key to this success is changing the electrolyte. This happens to be a non-flammable one, so charging can be faster as well! And (this is my speculation) therefore you might be able to take your bike on the plane!!!

Electric car battery with 600 miles of range? This startup claims to have done it
 

Beekeeper

🍯Honey Monster🍯
Aug 6, 2019
1,745
2,194
Surrey hills
The future may have already arrived with a breakthrough in the energy density of lithium-ion batteries (the sort emtbs use).

Currently the energy density of these batteries is about 250whr/kg, well the sort that Tesla use anyway. Tesla believe that they can push that to 330whr/kg. Meanwhile the US Dept of Energy are funding a programme that will lead to 500whr/kg. If that is achievable then your bike may go twice as far as it can now! :)

But in Apr'19, Inolith - a small start up in Switzerland, claimed to have achieved 1000whr/kg. So not only will the battery propel your bike twice as far, it will weigh half as much! :love:

Inolith are claiming that they need 3-5 years to get to a commercial stage, so late 2022 at the earliest. But I suspect that cars and mobile phones will be in the queue before emtbs! :(

Oh and a nice PS: The key to this success is changing the electrolyte. This happens to be a non-flammable one, so charging can be faster as well! And (this is my speculation) therefore you might be able to take your bike on the plane!!!

Electric car battery with 600 miles of range? This startup claims to have done it

Wonder if the longevity will be improved also. Will we still see a 20% drop in capacity after 500 charge cycles?
 

Dirtnvert

E*POWAH Elite World Champion
Sep 25, 2018
1,352
1,600
BC Canada
They could make the wiring cleaner and more durable now. Those little wires sketch me out. Especially the one going to the speed sensor, constantly moving on the swingarm
 

Akiwi

🐸 Kermit Elite 🐸
Feb 6, 2019
986
1,286
Olching, Germany
With the internal gearbox systems, I wonder if regenerative breaking would be possible? I have often done huge climbs with epic downhills with heaps of breaking and thought it would be great to be able to harniss that energy.
 

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