Introducing the Electrom

tigcross

100 W
Joined
Oct 18, 2015
Messages
177
Location
Victoria BC
Finished Electrom1.jpg
[youtube]nintW1BHDdU[/youtube]
Hey everybody, I think I’m finally ready to show you all the project that I’ve been pursuing for the past year (not counting the three previous years of drawing and re-drawing plans. I’m calling it an Electrom. I built the frame and body from scratch to create a vehicle with a specific set of characteristics I wanted based on research I’ve done over 14 years. This is the 4th electric bike I’ve built, and incorporates a lot of lessons learned in that time. Not to say that all of that time was spent building bikes: life, jobs, and kids do take time as well.

The Electrom runs a 72 volt 20AH battery, a 40 amp Grinfineon controller, Grin Cycle Analyst, and 10” QS hub motor with a 3.5 inch tire to make a 17” diameter wheel. It is piloted via understeer handlebars connected to the fork via an aluminum and carbon reinforced control rod. The wheels, breaks and front fork are spec for a Tag 500 Ebike, a type of electric scooter/bike sold in here in BC by KG’s cycle. It has hydraulic disk brakes, regenerative breaking, mirrors, lights, break lights and turn signals. There is a front fairing and a back tail-box with an easily detached cargo hatch for the carrying of passengers or large cargo.

One of the most novel features of the Electrom is that the rider’s pedaling energy goes into an on-board generator made from a small DD hub motor. This allows the rider to pedal at a constant cadence regardless of the speed or terrain, it also means you can keep pedaling while coasting to a stop or going down hill. The result is that the rider doesn’t have to think about gears, and your quality of exercise is greatly improved. In order to comply with legal ebike definitions, and to have some human energy available when a hill is too steep for the hub motor. I’ve designed a system where the rider’s pedaling energy is split between driving the generator and driving the back wheel via chain. The chain from the rider’s cranks goes down to a hub, where there is a cog that connects to the back wheel via chain, and on the other side of the hub there’s a 54 tooth #25 chain sprocket that drives the generator hub motor. The gear ratio for the back wheel drive is very low so that as soon as the vehicle is going over about 5 kph the back drive starts to freewheel. This is might sound like a complicated system but it is actually pretty simple. In addition to satisfying the legal definition of an ebike, it also means that when you encounter a really steep hill you can help the DD hub motor out with your leg power. The main benefit is simplicity of operation. The rider can just pedal at a constant cadence with constant resistance and no need to shift gears to match the vehicles speed.

The top speed at 84 volts is 55 kph, but the fastest I can legally run it here in BC is 32 KPH. I keep my top speed limited to 40 KPH and here in the city of Victoria BC I have been riding it for the past year with no hassles from the police. I think that they see that I am clearly peddling and that makes it ok by them. I hope that we can convince the BC government to allow a top speed of 42KPH similar to California, as I’ve found around 40 KPH to be the sweet spot in terms of getting where I want to go fast enough and having a decent range. The goal in creating the Electrom was not to build some kind of overpowered cheater vehicle, but to make something that tries to fit the legal definition of a bicycle while achieving as many of the conveniences of a car as possible.

Range at 32KPH is 80 kilometres, at 40KPH about 50 kilometres, and at the top speed of 55KPH I’m lucky to get 35 kilometres. I find that for most of my use in the city I charge the battery to 80% and never run low as most of my trips are short. There is room on the frame for another 40 AH of batteries when I can afford them. Most of the time I run the controller with a 1800 W max as I find this to be the sweet spot between acceleration and range. Thanks to the position and aerodynamics of the fairing the bike can easily maintain 40 kph on the flat using 500 watts or less

The body panels and tail-box are all easily removable for access to the inner working or to change a flat tire on the rear. (but with the big scooter tires and tire sealant I’ve not had to deal with a flat). I have also made up a fixture I can mount on the tail-box to allow me to carry my MT bike out to our local MTB riding area. The tai-lbox cargo area is very spacious and easy to access.

Rationale
I believe that what most people really want is convenience; By “most people” I don’t mean the users of this forum, we’re all sprocket heads who are willing to deal with mechanical complexity. “Most people” are the folks that never got out of their cars in the first place because they see the car as more convenient. In oder to convince a few more of these folks to ditch their lane-hogging 5 passenger cars the alternative needs to offer some advantages.

The design of the Electrom is based on the premise that while it legally qualifies as a bicycle, it is not really a bicycle. To my mind a bicycle can be carried up stairs and stored in your apartment, a true bicycle can also take advantage of intermodal transport solutions like the bike racks on city buses. By that definition the Electrom is not a bicycle. My thought was that there could be another form of vehicle, somewhere in-between a bike and car, and that if we desperately cling to all aspects of a bicycle in our ebike designs we will be unable to truly innovate. The Electom is easy to get on and off of, immune to traffic jams because it’s a “bike”, can be legally parked wherever a bike can go, is able to carry a lot of cargo. It has some protection from the elements, is highly visible and therefore safer, and allows the user to pedal as little or as much as they want. The Electrom offers things that a conventional bicycle can not, but to do so you have to give up the lightweight simplicity of a conventional bicycle, but then most ebikes have already given up many of those features already.

I also wanted to see if I could use electrification to solve some of the recumbent bicycle’s inherent flaws (hard on hills, too low to be seen and therefor unsafe) and to see if the recumbent position could help with one of the biggest challenge to e-bikes–where to put all that battery weight. Along the way I realized that I was building a completely new class of vehicle (kind of a grandiose statement I know). This is not a bicycle, Motorbike or car, but a kind of velomobile ( but not one you need to be a contortionist to get into). it’s widest point is the handlebars, this allows the user to take advantage of the gaps in traffic that a bicycle is entitled to use in most jurisdictions. It’s pretty long, and needs to be in order to fulfill it’s other design requirements, but slipping through traffic easily is more about width than length.

The Electrom will not be for everybody, it’s a two-wheeler and so the rider has to be comfortable with that. Slippery road conditions can be tricky, and most batteries don’t like being cold, so it’s not an ideal Northern-winter vehicle–it wants the same riding conditions as a motorcycle.


Construction Techniques
I built the Electom from scratch using carbon fiber, kevlar, fiberglass, aircraft epoxy, 1/8 aircraft birch plywood, hickory for bolt points, and aluminum. If one were to mass-produce the vehicle you would not build it this way, but these were materials I could work with in my limited shop, and they offered flexibility of design, which I wanted for a prototype build like this. The welded aluminum swing arm I had a friend help me with in his better equipped shop.

The design is basically a monocoque with large access holes to fit batteries, controller and other components. I did my drawings in Adobe Illustrator (I’m a graphic designer by trade) and while Illustrator is not a mechanical design program, I found it to be sufficient. I think it helps that I’ve been thinking about this design for so long that I pretty much had a 3D model in my head. One handy part of drawing it in Illustrator was that I did the drawings at full size, and was able to have large paper template sheets printed out for my cut-out plywood& carbon shapes.


Riding Characteristics
The Electrom is a big vehicle when compared to a bike, but it handles pretty well. It is fully suspended and has 3.5 inch tires so bumps and potholes are not a problem. It definitely handles slower than an upright bike and this takes some getting used to. It can really carve the turns though. I find that for most riding I relax with my back against the seat, but if I want to negotiate a series of quick turns I just pull my back away from the seat back and this allows me to steer more with my hips, kind of like slalom skiing.

One unexpected benefit of the high-pedal long-wheelbase and generator drive is that you can pedal all the time, even thought corners as there is no danger of your pedals striking the ground. The LWB and full suspension also makes it easy to keep your feet on the pedals over bumps. In fact I’m just riding a set of cheap plastic pedals and my feet never fall off.

The range depends on the speed I go and the wattage the controller is set at. At 1200 Watt Max and a top speed of 32 KPH I get about 80 kilometre range. At 1800 Watts and 40 KPH max I get about 50 kilometres. At 2800 Watts and 55 KPH top speed I get about 35 kilometre range. The top speed for this build of the Electrom is 55 KPH but it the design could easily handle more speed. I had it’s predecessor, which used a larger diameter rear wheel, up to 90 KPH and it was very stable at that speed.


Summary of the Electrom’s Features:

Generator Drive - The generator drive acts like an automatic transmission for a bike. The rider’s energy goes from the cranks to a hub that sends it to both a generator and the back wheel via a chain drive. As soon as the vehicle exceeds 5 kph the chain drive is in freewheel mode and all of the rider’s energy goes to the generator. The rider is free from the need to shift gears and can just pedal at a constant cadence producing electricity. An average fit person can generate about 150 watts continuously. It is true that this is not the most efficient use of human energy, but when the vehicle can put out up to 2800W there is not much point in obsessing about how efficiently you use the average riders 200W.

Ease of use - the Electrom has been deigned from the ground up to be easy to use. Stand-over height is just 17 inches and thanks to the swing-away front fairing, easily deployed center-stand and understeer handlebars, getting on and off is super easy. This combined with the fact that there are no gears to shift through make for a very pleasant riding experience. It also has mirrors, lights, turn signals and a quick-deploy centre stand, all of which make it easier to use.

Slips through traffic -
The Electrom is legally a bicycle, and as such is allowed to lane-split. This and the fact that the widest part of the Electrom is it’s handlebars at 27 inches, allows the rider to easily get past stalled traffic. It’s motorcycle grade tires are stable and safe at speed and make riding on the shoulder of the road where all the sewer grates, debris and bumps are much less nerve racking.

Cargo and passengers - the back tail-box has been designed to handle cargo (up to five grocery bags), and with the easy removal of the cargo hatch it has room for a small adult passenger.

Clean appearance & no greasy chain - The electrom is mechanically simple and the majority of the mechanical components and wiring out of site under body panels. The Panels are easily removed for maintenance. The drive chains are all hidden away where they can’t stain the riders clothes

Great visibility -
The Electrom is safer in traffic than most recumbent bikes because the higher rider position puts the rider at eye level with other road users. The vehicle’s size also makes it much harder to miss.

No hard-to-find parts -
While the design of the Electrom is different, it uses as many off-the-shelf parts a possible in order to keep manufacturing and repair costs down.


Some of the Questions I’ve had so far


Why not a trike?
I had several reasons for sticking with two wheels; 1. I like carving through turns; 2 one of my main design goals was to keep it simple, and a trike is by nature more complicated, 3, vehicle width and aerodynamics–as I knew I wanted a high rider positions it would have had way too much frontal area as a trike. Also, a trike is much wider at the pavement, which means that if your occupying a 48 inch wide curb lane with your 36 inch wide trike you only have 6 inches between your wheels and the curb and the the vehicle next to you. On the Electrom my vehicle width at the pavement is only 3.5 inches so I have much more room before I have to worry about my tires scrubbing up against the curb or the cement truck in the lane next to me.

What if your electrical system fails, can you pedal it home?
Not really. There is a single low speed connected from the pedal to the back wheel, but heaven help you if you actually tried to use it by itself. But then you don’t expect to be able to push your broken car or motorbike home either.

Why not use a mid-drive?
You could definitely use a mid drive on a vehicle like this if you wanted to, I opted for DD because I wanted to make operating the vehicle as simple as possible, and I wanted the re-gen breaking as the vehicle weighs close to 100 lbs.

Do you get a lot of questions?
I sure do, and almost all of them are really positive. People are very excited when I finish explaining what the Electrom is and what it can do.

So, what’s next?
As I said, people are pretty excited by the Electrom and I have had several offers to purchase it outright. I am considering some kind of crowd funded campaign to produce a kit version of the frame, body panels and tail box.


Electrom Build1.jpgView attachment 15Electrom Build2.jpgElectrom Build3 Paper temaplate for Carboun cover layer.jpgIntroducing the Electrom: a human/electric Recumbent Two-Wheeler.
 

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Thanks for sharing your project. I think something like this has been needed for a long time. There are others out there as well, but your version has a lot of promise. I can tell that you put many nights of thought into defining the purpose and intended audience, something that is -at times- lost in the excitement of creating something new.

I especially like the ease of ingress, egress, and parking in the Electrom.

One question: Have you done any crash testing? Laid it down ever and tried to pick it up?
 
Hi Cal, Regarding your question of having laid it down, I did crash the previous version at about 40 KPH, it hurt, but I was happy with how it went. It slid out on a corner and I slid along the pavement with it for a bit. I had decent gloves and helmet but at that speed some motocross or perhaps BMX clothing would be good.
I've dropped this version, and laid it down at speed twice, once at about 10 kph and once at about 20 kph. It does scratch the paint but the bodywork has handled the impact well. It's pretty easy to pick back up as almost all of the weight (Battery, motor, generator, and controller) is in the lower third of the frame.
 
cal3thousand said:
Thanks for sharing your project. I think something like this has been needed for a long time. There are others out there as well, but your version has a lot of promise. I can tell that you put many nights of thought into defining the purpose and intended audience, something that is -at times- lost in the excitement of creating something new.

I especially like the ease of ingress, egress, and parking in the Electrom.

One question: Have you done any crash testing? Laid it down ever and tried to pick it up?

...and thanks for your positive feedback
 
Amazing.
How was the windshield made?

The windshield was from Windwrap, they've been bought by TarraCycle. Mine was the experimenters large, I don't think they make it any more. The windshield support beam is made with Carbon cloth over a shaped foam core. The wiring conduit is built into the beam.
 
Nice build!
 
Such a low center of gravity! would be a hoot to ride on quick canyon/coastal roads! :mrgreen:
 
tigcross,

Congratulations! You have nailed it. Ever since repairing the frame on my cargo bike, I have been avoiding the washboard gravel roads I have come to love. Fat tires and suspension would be awesome. What is the wheelbase?

Not finding your website. Can you provide a link?
 
tigcross said:
Rationale
The design of the Electrom is based on the premise that while it legally qualifies as a bicycle, it is not really a bicycle. To my mind a bicycle can be carried up stairs and stored in your apartment, a true bicycle can also take advantage of intermodal transport solutions like the bike racks on city buses. By that definition the Electrom is not a bicycle. My thought was that there could be another form of vehicle, somewhere in-between a bike and car, and that if we desperately cling to all aspects of a bicycle in our ebike designs we will be unable to truly innovate. The Electom is easy to get on and off of, immune ato traffic jams because it’s a “bike”, can be legally parked wherever a bike can go, is able to carry a lot of cargo. It has some protection from the elements, is highly visible and therefore safer, and allows the user to pedal as little or as much as they want. The Electrom offers things that a conventional bicycle can not, but to do so you have to give up the lightweight simplicity of a conventional bicycle, but then most ebikes have already given up many of those features already.

That sounds a lot like how I've worked out first my CrazyBike2, and now my SB Cruiser trike. :) Though I don't really think my stuff could be used as a basis for something others would want to use--yours could.

I definitely wish you good luck with converting others to this mode of travel. :)
 
At first i thought you had beaten me to one of my ideas but when i read your whole post i realise you're idea is totally different and i wonder whether we could have these legally in the UK (i doubt it).

My idea was a converted emax 110s scooter to be a feet forward recumbent like a Quasar, an early FF motorcycle, (i hadnt even bothered factoring in human powered drive) from a visual perspective your Electrom looks very similar to how mine might end up if i ever get round to it. I think this will be a great kit vehicle. One of my other interests is CNC and i think you could have a lot of people using something like mpcnc to reproduce this kit to batch manufacture it in their own sheds.

Thanks for sharing.
 
Hi everybody, thanks so much for the positive feedback so far. This forum has been a valuable source of info over the years and It's great to be able to give a new idea back to the group.
I've put up a basic website at http://www.electrom.ca but to be honest, right now there's more info in my initial write-up on ES.
Yesterday I loaded up my spare battery and rode from Victoria BC to Parksville BC. it was a 150 KM trip that took me about 5 hours with a few stops. I rode at night and in the rain. The Electrom handled it all beautifully.
 
This is really great! I've often thought there should be a class of vehicles with the mixed advantages of cars and bicycles, and I think you've done an amazing job of marrying those things!
 
Really nice build here. Attention to detail, I like this long low riders. Don't want to post anything negative but you have to do something about that windshield. I get the aero part but it really is a hazard. Frontal crash and you might end up without your head. If you could make it higher that would help with the rain as well. Just my few ct
 
Very nice! From design to completion. Well done. Congratulations!
 
Don't want to post anything negative but you have to do something about that windshield. I get the aero part but it really is a hazard. Frontal crash and you might end up without your head. If you could make it higher that would help with the rain as well. Just my few ct

Hah hah hah, I had thought of the decapitation thing, there's also the old "James Dean" where you impale yourself on the steering column. I don't have that problem as it's an understeer. The windscreen is made from quite thin and flexible Lexan supported on a carbon and foam beam. Both were designed to crumple in a front end crash, and neither is anywhere near strong enough or sharp enough to cause harm.
I had considered a higher windscreen to protect my face from the elements, but that would have necessitated windshield wipers. As part of my deign criteria was to keep it simple, I opted for the lower windscreen. I also prefer the aesthetics of having the windscreen at the same height as the tailbox.
Another determining factor on the design was the amount of surface area I wanted to present to cross-winds. The lower the windscreen was, the less surface are and less the vehicle is effected by cross-winds.
 
whereswally606 said:
At first i thought you had beaten me to one of my ideas ...

Actually you definitely have beaten me to my idea! I arrived at a very similar topology with nearly identical rationale. But mine is still just a plywood tub with a pile of parts and dusty sketches, yours is well thought out and beautifully complete.

I think you should definitely crowdfund, I'm interested!

Although my wallet and my ego are protesting ... it seems beyond us DIY ES rebels to commit that much time and cash simply to replicate someone else's superior design ;) On the other hand jumping into production for the non-us is quite a risk.

Maybe target kits or plans as school shop projects? It looks like something shop teachers could complete in terms of skill and budget. Or home-school/alternative schools - they give credits for any project under the sun. Electrom is much lower cost and quicker build than a car. Much more accessible and therefore motivating to kids without licenses. Then those kids could go on to start up businesses as your sales and service dealerships, and your international design and engineering team ...

Are you bringing it to Elecrafest to face off with the Veemo?
 
tigcross said:
Elecrafest looks cool, I'll try to make it over.

IMO Electrafest has gone from very fun to a just a boring parking lot of cars and consumers. I gave up after last year and surrendered the "kid's zone" to a car person. I don't remember if Justin even showed up. VEVA used to have an after-party BBQ with free beer at a micro brewery. Now just a quick pizza on hot tarmac.

If you do decide to come over, I'll work to change that. I'll call all the non-car people, maybe we could get an alternative venue... like Creekside park/Science World, or Olympic Village ... we could have "the more fun party". But since the idea really is to get people out of cars, it might be better to stay attached to Electrafest and siphon off the VEVA car consumer audience to LEV alternatives. Also good to glom onto their advertising, organization and insurance. Many of their dedicated volunteers are hobbyists/non-car people who are just sort of stuck with a boring-ized VEVA so don't worry about gloming on, the rank and file would love it.

I can also call out the high-school shop teachers and the alt-school people if you really are interested. School is ending soon though, so need to decide quick. I could supply you with a tent or two and lawn chairs. I live a few blocks away. Do you know the Victoria & islands LEV people?
 
Tigcross,

Awesome vehicle with a well thought out plan and great execution. That kind of layout permits a mountain of batteries for serious range at even greater speeds.

Here I'm subject to a vaguely defined 5kw limit than no one knows about to enforce, so I take full advantage of the liberal definition of what's allowed on the road without registration and taxes. Hell, I don't even need pedals, though I love the approach you took in that regard. My experimental ebikes end up as exhilarating highway speed capable fun machines for basic transportation, but it's time to step up my game with a fairing and rain protection.

What kind of wh/km are you getting?

When you go long and low, how do you decide on the steering geometry? Does wheel size make a difference? I've gotten lucky so far by just guessing and going with what looks right, but cutting steel and re-welding is easy. I'd want more confidence in the final result before going through the effort and time investment of a composite construction.
 
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