Introducing the Electrom

After another read-through I've got more questions. I've been sitting on a bunch of carbon, both cloth and uni-directional, and really want to do some form of composite layering like you've done. Under 50kg is great! Can you go into detail about your layering of the plywood and carbon with resulting thicknesses and how you joined them at the corners?

Have you done an all up weight at the front and rear tire? I ask because Electrom seems heavily rear biased with the pilot aboard, and my 9yr old long wheelbase cargo bike is my only EV that is drastically lighter up front. Riders have eaten asphalt on it more than any of my ebikes, all in poor traction situations, and I attribute it to being too light up front making the front wheel too easy to wash out.
 
John in CR said:
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.

Hi John here are some answers for you:
I am getting a range of about 80 km on a 20 amp hour 72 V battery if I run at the bicycle legal speed of 32 km/h (here in BC). However in the city I usually run about 40 km/h, carry a lot of groceries or kids, and get a range of about 55 km.

I arrived at my geometry over a Long period of experimentation. My head angle is quite slack at 66°.

Wheel size definitely makes a difference. I'm running 10 inch scooter wheels with 3.5 inch tires to yield an outer wheel diameter of 17 inches. On the front a larger front wheel equals a higher head tube and thus larger frontal area and higher step over height. I was going for a low step over height and settled on the 17 inch wheels because they were big enough to roll over the junk on the side of the road, but kept my step-over height reasonable. On the back, a larger DD hub motor inside a smaller wheel equals more torque for climbing hills (although with your 5KW allowance that might not be an issue for you). There is also an added gyroscopic stability effect at high speed from the smaller wheels spinning faster. Here in BC the grey-area limit seems to be about 1200W. My bike can climb hills on that power, but I've found 1800W to be the sweet-spot for power vs efficiency
 
John in CR said:
After another read-through I've got more questions. I've been sitting on a bunch of carbon, both cloth and uni-directional, and really want to do some form of composite layering like you've done. Under 50kg is great! Can you go into detail about your layering of the plywood and carbon with resulting thicknesses and how you joined them at the corners?

Have you done an all up weight at the front and rear tire? I ask because Electrom seems heavily rear biased with the pilot aboard, and my 9yr old long wheelbase cargo bike is my only EV that is drastically lighter up front. Riders have eaten asphalt on it more than any of my ebikes, all in poor traction situations, and I attribute it to being too light up front making the front wheel too easy to wash out.


I've not done an actual weight, but you are right, most recumbents end up rear-heavy due to the fact the 2/3 of the riders weight is biased to the back, as opposed to in the middle as on an upright bike.
I've placed as much weight forward on the Electrom as I can, the generator hub is in front as are the batteries. It has not problem with wash-out on pavement–which is what it was designed for–but no LWB two-wheel recumbent is happy on gravel roads and the Electrom is no exception. Learning to ride it takes about 5 minutes to get the basics, but it is very different than a conventional bike and steering it properly at speed has to be learned over time. It requires a very light touch.
 
John in CR said:
After another read-through I've got more questions. I've been sitting on a bunch of carbon, both cloth and uni-directional, and really want to do some form of composite layering like you've done. Under 50kg is great! Can you go into detail about your layering of the plywood and carbon with resulting thicknesses and how you joined them at the corners?

Sorry John, I missed answering this one.

I can give you basics, but I don't actually recommend you follow my process. An aluminum frame would be lighter in the end. My method required a lot of work and had some pretty weird steps. I'll give you a basic expalnation but I'm not going to make a how-to book or anything like that.

To make each side panel:

Start with a smooth waxed surface to do your layout on. It has to release the cured epoxy later

Lay down the basic shape of your frame profile + a couple of inches in two layers of 8 oz carbon bi-directional weave cloth. I cut the cloth to match angels and used tow layers of cloth tho make sure I had cloth over-laping cloth on the joints.

Mix up a big batch of slow cure epoxy and saturate your two layers of cloth

Lay one sheet of 3 mil aircraft birch ply over the mess (don't loos track of where your first layer is)

Put down the basic shape again, making sure it line up onto of your first layer. This time using a carbon/Kevlar mixed cloth, again two layer

Mix another big batch of slow cure epoxy and saturate your two layers of cloth

Lay your final sheet of 3 mil aircraft birch

Place mastic material, release cloth and vacuum film and vacuum clamp it all together.

Now do it again for the other side. Each side panel ended up about 1/4 inch thick


Once both sides are cured, peal them up, line them up and stick them together flat. now you have to put down a paper template of your shape and using a jig saw, cut it out of your plywood shapes. Cutting thought the kevlar is a smokey, nasty job and should be done outside. You will need several blades.

I built my headtube and pedaling station as a unit, by taking the front end of a Norco Torrent which has really thick tubes, chopping it off and laminating it to plywood using multiple layers of ply, kevlar and carbon. The headtube/pedaling station is the width of the inside of the frame and the side panels are attached to it.

the other spacers that separate the two side panel were made from strips of 1/2 inch ply, accept for bolt points which were made from one inch hickory board.

I then epoxied and screwed the side panels to the spacers and pedaling station/headtube, keeping the screws 1/4 inch away from the edge so I could round all of the corners with a sander.

Then, finally I wrapped the would thing in two layers of carbon cloth folding the inside edges over inside the frame and holding them there with cut Styrofoam. saturated it all with epoxy and vacuum bagged it. upon taking it out of the bag much sanding and finishing ensued.

Ok, that said, I suggest that you do your frame in aluminum. It's much easier, and because there was no way to know if what I was doing was going to be strong enough I overbuilt it by quite a bit.
 
tigcross said:
... because there was no way to know if what I was doing was going to be strong enough I overbuilt it by quite a bit.

I'd say! Apocalypse proof construction and a very impressive finish!

But if you want to experiment with design more cheaply, check out my other hero; http://www.carzari.ca/news.php 1/4" plywood edge joined with a borrowed pin nailer, finished with house paint. Sanding optional. A nice cheap way to experiment with design! I'm also impressed with his Monty Python aesthetics.This thing has been running for years. Last I saw him I wasn't able to catch up to him to ask if he improved on his non-redundant bicycle cable steering, nor if his wife still lets him haul the kids around. But he doesn't seem like the type to let the odd near-fatal accident stop him.
 
1JohnFoster said:
tigcross said:
... because there was no way to know if what I was doing was going to be strong enough I overbuilt it by quite a bit.

I'd say! Apocalypse proof construction and a very impressive finish!

But if you want to experiment with design more cheaply, check out my other hero; http://www.carzari.ca/news.php 1/4" plywood edge joined with a borrowed pin nailer, finished with house paint. Sanding optional. A nice cheap way to experiment with design! I'm also impressed with his Monty Python aesthetics.This thing has been running for years. Last I saw him I wasn't able to catch up to him to ask if he improved on his non-redundant bicycle cable steering, nor if his wife still lets him haul the kids around. But he doesn't seem like the type to let the odd near-fatal accident stop him.

Yes I know the Lecicle well, a very cool project. I think their inspiration was more about creating a protected area for kids.
 
Thx for those construction details. It's a big help. I thought Electrom looked overbuilt from the thicknesses I was seeing and your details confirmed it. I'll probably shortcut the process with epoxy impregnated ply to start, and then go carbon and glass once the basic form is assembled....maybe some harder to cut kevlar or kevlar/carbon cloth where I feel some additional toughness is required.

Re AL, I'll never go that route as I could never have confidence due to the manner in which it fails. It took the moto manufacturers decades to get it right, and since aero trumps weight at my speeds I'd always go with simpler to work and warning before failure nature of steel. Since I'm not pedaling a few kg is irrelevant to me, I'll likely go with a light steel skeleton and use composite panels to give it rigidity.
 
John in CR said:
Thx for those construction details. It's a big help. I thought Electrom looked overbuilt from the thicknesses I was seeing and your details confirmed it. I'll probably shortcut the process with epoxy impregnated ply to start, and then go carbon and glass once the basic form is assembled....maybe some harder to cut kevlar or kevlar/carbon cloth where I feel some additional toughness is required.

Re AL, I'll never go that route as I could never have confidence due to the manner in which it fails. It took the moto manufacturers decades to get it right, and since aero trumps weight at my speeds I'd always go with simpler to work and warning before failure nature of steel. Since I'm not pedaling a few kg is irrelevant to me, I'll likely go with a light steel skeleton and use composite panels to give it rigidity.

I agree, mine frame and body is heavier than it needs to be, but once you consider in the weight of the motors, batteries and rider you realize that trying to shave pounds and ounces off of the frame is pointless. I think a steel frame with composite panels will work just fine.
 
Wow, beautifully done build. I wish I had the expertise to build something like that from scratch! Haha. I like the recumbent design and elegance of the layout, I like long trips on my bike so I can see how you can tackle a 100+ km ride in the electrom. Well done!
 
Seanatomy said:
Wow, beautifully done build. I wish I had the expertise to build something like that from scratch! Haha. I like the recumbent design and elegance of the layout, I like long trips on my bike so I can see how you can tackle a 100+ km ride in the electrom. Well done!

Thanks Seanatomy, alsways good to hear that others think you are on the right track. The Electrom is very comfortable on long trips, but also excels in congested city traffic. I've put up a quick little video of a short city traffic ride.
[youtube]rSBMbB-A_vU[/youtube]
 
our family made a trip to the Campbell Bay Music Festival on Mayne Island this weekend and I was sent as the advance party to stake out a campsite. because bicycles get on all ferries with no waits an ebike makes a lot of sense here on the West Coast of BC where we live and die by the ferry lineups.

I have a decent little cargo trailer to which I added a 150 liter storage container to take all of our camping gear. The loaded trailer and cargo in the Electrom's built in hold added about 100 lbs. I'm happy to say that the Electrom handled it beautifully. My top speed was only down by 4 kph and the 35 k trip out to the ferry terminal only took 1.5 more AH than normal without the trailer.

Mayne has some very steep hills, hills that would have been too steep for the motor by itself, but with the pedal assist I was able to grind up them easily. The system is seamless, with the pedal assist starting to kick in at once you drop down to about 7 kph.
 

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Well, after a long summer mostly out of town I've finally been able to get back on the Electrom for some serious mileage. In the last three weeks I've put almost 500 kilometers on the bike just doing errands around town and highway efficiency test.

I've been tuning my throttle-out and wattage rates on the V3 to find a balance between performance, range, and human/electrical interface. I really like setting my top speed with the throttle out instead of the max speed as it is way smoother and predictable. Things are pretty dialed now, I'm still running a 72 volt, 20 amp-hour battery and a Grin 40 amp sinewave controller with a V3.

My "around town" setting gives me 1500 watts, a top speed of 40 kph and a range of 60 kilometers on a full charge.
The "super econo" setting gives me 1200 watts, a 35 kph top speed and 90 kilometers on a full charge.
The "unlimited" can draw up to 2900 watts, has a top speed of 55 kph, and I expect a greatly diminished range. I've never run the bike at this setting for a whole battery cycle so I can't say for sure what the range would be but I estimate it would be around 30 kilometers on a full charge.

a new vid from the summer:

[youtube]34WW0iZk8s0[/youtube]
 
Nice and thoughtful build!
 
:shock: :shock: 8) :mrgreen:
 
There you are :lol: , i turned around a few weeks ago near the baseball field at Caledonia and started the chase on my ebike,but i lost sight of you.then i saw you again and i was walking, so didnt run after you..Mark.
 
tigcross said:
Postby Drunkskunk » Mon Sep 18, 2017 7:14 pm
Wow. really nice build. First bicycle ever with a Rumble seat?
That's pretty funny, I'd not thought about it that way before. Thanks.

Well... Charles Mochet had pedal power with rumble seats in the 30's, but they were 3 wheel. Mine has a rumble seat too, but driving it has only reinforced the impracticallity of a wide track 3 wheeler. Last weekend I drove it to a BBQ and one driver tried to yell me off the road. I easily caught up to her at the next stoplight and tried to smile her out of it, but her point was kind of made. A lot of people put kids on the back of long wheelbase bikes, but they are completely exposed to weather.

The Electrom is a really nice middle ground driver+kid bike because it is semi-enclosed but still easy to park and able to pass cars on the right.

Thanks for the video it really shows how practical your layout is!
 
Tig let me drive the Electrom today and gave me a lot of background on his design philosophy.

It was great! After Tig was able to "let go" and I was romping around the the park, it was very stable and easy to handle. I have no experience on recumbents, so the handling and ride on bumpy ground was quite impressive. It's a very solid vehicle. I think this is a really good configuration that will suit a lot of people wanting a car alternative. It wasn't raining today, but sitting in the cockpit I could see the practicality of the "mostly covered" design. When we rode off down the street, Tig on the Electrom looked much more visible than low slung velomobiles I've seen. It's much more parkable and traffic worthy than a velomobile, and much practical and weather worthy than than a bike. I want one!

Unfortunately I didn't bring a tripod, and I'm terrible at photos and vid. You need a Tomoe for that. Maybe next time. I also promised to buy Tig lunch, but that was graciously forgotten in all the excitement of decades of design and development.
 
Thanks for the review John, next time you come over let's make time for you to ride it and the street and for much longer. And a note to anyone else in Victoria, I am looking for test riders. I've been riding this vehicle for over a year now and loving it, but now I need feedback. Good and bad, it's all important.
 
Hi! What did you use to mount the cycle analyst? I'm looking for a solution on my kmx recumbent.
regards Shane
 
tigcross said:
Thanks for the review John, next time you come over let's make time for you to ride it and the street and for much longer. And a note to anyone else in Victoria, I am looking for test riders. I've been riding this vehicle for over a year now and loving it, but now I need feedback. Good and bad, it's all important.

Crazy Victorians... Having been moving about all my life... Having lived in and visited numerous cities and places...
in North America... in England and all over Europe... and although having lived on the island but twice, briefly... (including once born there)... and sum total "briefly"... I still miss you guys (and grrrls...)

Next review (I hope)? A recumbent trike. :wink:
 
Hi! What did you use to mount the cycle analyst? I'm looking for a solution on my kmx recumbent.
regards Shane

Hi Shane, My Cycle Analyst is mounted to a carbon and foam beam that I made to support my windscreen, mirrors and fairing.
I made it by carving the shape I wanted in Styrofoam, embedding a piece of half inch tubing as a wiring conduit, and then covering it with carbon cloth and resin. It's designed to crumple if I have a crash as I'm not looking to be impaled on my bike. The windscreen came from Windwrap which is now sold by TerraCycle.

I hope this helps,

Tig
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