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Thread: Recumbent Electric Motorctycle/Bicycle

              
   
   
  1. #1
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    Recumbent Electric Motorctycle/Bicycle

    Hi guys, I thought I'd share some photos and a basic description of my ground-up build of a recumbent electric motorcycle/bicycle.

    The basic concept is a recumbent motorbike that you can pedal if you feel like it. The top speed is 80 KM, (about 50 mile per hour). It handles great at that speed, and is surprisingly stable and easy to steer. I've set it up to carry kids and cargo, and use it around town quite a bit. As I keep the speed low most of the time and it has pedals, I've so far been able to pass for a recumbent bicycle and have not had to register it. (I do have lights and signals though) I think that when cops see anything recumbent go by they just think "there goes another of those weird recumbent bike fools, better not stop him he'll bore me to death with talk of superior drag coefficients..."

    The human energy goes in via a Rohloff 14 speed hub rigged with a sprocket to pass it back to the rear wheel via chain.
    It is an understeer that uses a control rod steering system.
    the front fork and wheel is off of an X18 pocket bike, the rear wheel is a Crystalite Crown hub motor laced into a 24 inch MTB DH rim running a Lyne 90 amp, 72 volt controller.

    This is version 3, I started version 1 about 12 years ago, it's been a fun project, interrupted by kids, and other life events. Of course I'm now itching to build version 4
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  3. #2
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    Love your bike. Saw you in the video on Justin's site.



    Is that a TC4080? And is that a 24 cell, 40 Ah, GBS pack? I am curious as to what kind of Wh/km you see at 35'ish kph speeds. Any idea of the finished weight of the bike...without cargo?

    You are right about recumbents. With the pedals right out front for all to see..."Move on, nothing to see here."

    Electric bicycles are the perfect vehicle. I waited my whole life for these to become practical. I guess I should be glad they arrived by the time I retired. :-)

    Warren
    Last edited by Warren; 13 September 2015 at 0802.

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    Hi Warren, thanks for your interest, I've refereed to many of your articles on the recumbents.com website over the years.
    I went with the TC40100, as I thought I needed the higher speed, in the end I think the lower speed torque of the 80 would have been better. In truth the motor is overkill and a bit of a current hog, a 3000 watt max motor would have been sufficient for most of what I'm doing with the bike.
    On the question of Wh/km, I've not done a full test run in the 35kph speed range. my sweet spot is at about 45-50 kph, it feels fast enough to take advantage of my fairing, but not so fast that I draw too much attention to myself. I've gone 74 kilometres on relatively flat terrain at that speed and shut down before stressing the pack. it is a GBS 24 cell, 20 Ah pack, so about 1500 Wh. That made for about 20Wh per Km. I've got tons of room for batteries (a significant befit of a long wheelbase recumbent design) and I'm really excited to try a pack with the new high power 18650's. The GBS's are ok, but with some of the new stuff I could achieve double the power with same weight, and have way better burst power. exciting times...

    I estimate my vehicle weight is about 120 lbs without me on it.

    I agree that the electric bicycle is the perfect vehicle...as long as you live somewhere relatively warm and dry. The fact that most of us do not has been a major guiding factor in my design criteria. I feel that we are competing with the convenience, comfort and safety of a car, therefor all steps must be taken to make our vehicles as practical and easy to use as possible, because we're never going to get around the fact that bike and motorbike riders get wet when it rains.

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    Tig,

    You are confusing me with the younger, handsomer, more talented Warren Beauchamp of WISIL. :-)

    I am almost done with my second e-recumbent. I converted our old 1996 RANS Screamer tandem to a single cargo bike. I am running a TC4080 in a 24" downhill rim, an 18 fet, 60 amp EM3ev controller, and a seven Leaf module, 54.6 volt nominal pack. The pack came in at 61 pounds, and does 53 Ah from 58.8 volts down to 44.8 volts, 2.89 kWh. Bike weighs 130 pounds. I have done 670 miles so far. Longest ride so far was 131.6 miles at 22.1 mph average, 34.7 max in the 75% throttle position on my 3 speed switch, 17.5 Wh/mile with me putting in my 100 watts pedaling. I didn't get below 20 mph except for stopping at stop signs. The 100% position yields 28-32 mph for miles on end and about 25 Wh/mile.Leafpack3.jpgriderbreak.JPG

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    Hi Warren, sorry for the confusion. I'd love to see a side view of the Screamer. I love how low you were able to get the pack mounted. I think that's one one of the biggest benefits of the recumbent position.

    The rider position on your Rans reminds me of my 2nd try at an ebike. The geometry on the Version 2 build was inspired by my old Varna SWB recumbent (which was my first foray into electrification). On the Version 2 I was pursuing a human-energy-via-generator concept. The motor was an Etek running a 330 amp Sevcon controller at 48 volts. It was a MONSTER, amazing acceleration despite the 120 lbs of lead-acid batteries, and pretty decent handling. Now stopping was a bit of a problem... Top speed was 80 kph.
    I will go back to the human-energy-via-generator concept on my next build. It was not as efficient as a direct drive but the ability to pedal at a constant cadence regardless of speed or slope was very nice and something I'd like to explore further with today's technology.
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    This is the bike in its proof of concept stage. I have now pulled it apart. The frame is going for modifications this week. The boom will be shortened, and the bottom bracket relocated to the position assumed by the old MTB frame section, in this picture. The bottom of the frame will also be modified to raise the battery about 6", and run below it for protection. It handles great like this, but if/when I need to take the ditch, it would be destroyed.

    I am running a 60/46/26 triple up front, and a 14-34, 7 speed Shimano freewheel in the rear. The 46 tooth middle ring works well for riding in the 50%, bicycle speed, position. The 60 is good for 75% position. In 100% I only use the 14 tooth rear, and am spinning as fast as I can maintain. I will be looking for a quality, NOS, freewheel, with 12/13/14 for the smallest cogs. The 26 tooth granny is my bailout gear for "turtle" mode.

    I was going to do a 90mm Sturmey Archer drum brake up front, but the regen works so well down to 12 mph, I don't think I'll bother. I don't ride in the city, preferring small towns and backroads, so stop and go braking is minimal.

    I don't know who that eccentric, Attachment 6730old guy behind the bike is. :-)

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    Hey Warren, the attachment didn't stick, could you re-post?

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    Hey Warren, I think that look great, (as only a fellow recumbent aficionado might). Have you considered a Patterson or Schlumpf two speed crank? it would allow you a much smaller front chainring and therefore less chain interference when getting on and off the bike. I might also go to a suspension fork and 24" wheel up front.

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    I have no chain interference. I can lift my leg over my head yet. :-)

    As a former bike mechanic, I avoid IGH if possible. Your Rohloff is the only one I would consider, as it has fairly low losses, and is said to be pretty dependable. Not my experience with any other bicycle gearbox. Not a fan of bicycle sprung forks either. Too much play in most of them. I am lucky to live in a warm state that is still pretty flush with federal dollars. Our backroads are pothole free. In four years of riding my other e-assist, over 20K miles, I have hit two small dips in the pavement, no holes. I ride the center of the lane, except when cars approach, and have had one rear tire casing pierced by a flint in all this time. I flatted three tubes though that same hole before I remembered to put a boot in it. :-/

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