Electric Reverse Trikes. Ideas, Rants, Collaboration?

todayican2 said:
The tires are dot falkens mounted on plain ol' douglas wheels 5" wide the offset is "4-1" paid $12 a piece for the wheels :)

The more I think about this little 250, the more I want to drive the thing lol.

especially looking forward to doing some "body, on, body off mpg testing.

Very cool, thanks for the info. If I could find a set of used Douglas (or any) ATV wheels like that (10x5, 4+1) in 4/166, I'd be in heaven.

Speaking of bodywork and MPG testing, have you seen Craig Vetter's Helix scooter bodywork project?
Very interesting indeed...

Tom
 
Intimate with Craig and his work Tom, I also have been lurking at as many electrathon sites as possible ;)
 
I have been looking for some time ... here it is .....

http://nauasme.org/photos/album/72157611362560479/2008-bike.html

Maybe a little stronger for battery and motor, plus rack and pinion steering ?

3121975108_92bdb7833f_o.jpg
 
Very cool tank. Nice & light, too. I especially love the "Hobie Cat" tiller steering.

As you put batteries and a motor into it, though, and multiply the power, weight and speed you'll get going from 2 cyclist power to electric motor and batteries, aren't you very quickly going to run into the design limits of almost every part on this vehicle, from the steel frame tubes to the wheel bearings, rims and even tires? Seems at first blush like it would be simpler to start from scratch with a design like this and a power system of 48 volts or more, even with LiPO or A123 batteries.

Still, that's really a neat thing you've made there. Nice work.
 
for $10k you can get this ......

http://www.pureelectricvehicles.com/features.html

lftsideview.jpg
 
Yeah, the Trilectra. According to the website, this is coming in "Spring 2009" and on the videos from 2008 Bill Provence aimed to be in production "this fall."

No details, but the available videos from last year show the speedster-style prototype tooling around the Michigan countryside, at a described 35-45mph. I'm guessing this thing has 6 AGMs, runs at 72 volts, and would actually be a lot of new EV for the money at $10k, provided the components were good quality. This has one of the nicest layouts and is one of the more attractive trikes of its kind I have seen. Yes, it is unsorted and it looks to me like the headlights are mockups, and the doors on the speedster prototype aren't actually functional, but that was very early in the development, too. It was a fantastic idea the summer that gas in Michigan was over $4. Now, given everything that has happened since then, its going to be a hard sell to move every single one of them, even if it is a pretty good value.

Unfortunately, I fear the worst for this little car and start-up company. No updates to the website and nothing new on youtube or anywhere else since last September.

The short reply to "for $10k you can get this..." is:

Well, no, you probably can't.
 
Ok Tom A I have to ask... :)

Lets say, a 1000lb 2 seater with lexan "canopy" good looking in a "im the 2 seat better looking cousin of the sparrow" kind of way 100ah @72v 75mph top speed trike were to hit the market today, fairly well sorted.

What would it fetch for 4 units production a month?
 
todayican2 said:
Lets say, a 1000lb 2 seater with lexan "canopy" good looking in a "im the 2 seat better looking cousin of the sparrow" kind of way 100ah @72v 75mph top speed trike were to hit the market today, fairly well sorted.

What would it fetch for 4 units production a month?

Y'know, I think about that from time to time. There are at least three things to say about it:

1. I think the premise vehicle has problems. 100Ah at 72V times 80% DOD per cycle is under 6kWh. That's a very small pack, about the equivalent of 3/4 gallon of gasoline using the "8kWh of Lithium = 1 Gallon of Gasoline" Rule of Thumb. A 1000lb vehicle won't go more than 30-40 miles on that, at best, I would think. It is possible I'm confused on the math, but my calculations show this is about 170lbs of lithium, which I can tell from that fact alone its a very small pack for a half ton vehicle. It might hit 75mph, but range at that speed could be as little as 15 miles. Anyway, my point is that you'd need more like 400lbs+ of lithium in a 1000lb car to make it go fast enough and far enough to be commercially viable. Say more like 160Ah at 108V. That would give you nearly 14kWh usable, for decent range and performance, but I'm no EE and have no experience with the batteries, so its hard for me to work these numbers off the cuff with confidence.

2. Let's talk about costs. The batteries I'm describing are something like $6500 at today's prices. Another $2000 for a commercial-quality BMS, $3500 for motor, drive, controller and electronics, and $2500-$6500 for the finished rolling chassis, and the car is really no longer commercially viable. Mind you, this is for a good sorted car that I would like to own. Everything could be more, some of it could be less but, $14,500-$18,500 is what I would budget. I don't think that pile of parts could be profitably marketed, sold and supported for less than about double that, call it $25k-$35k. Think my numbers are unrealistic? See what the OEMs are going to do with EVs over the next few years (in the thousands of units annual production game, with all their in-place resources and competitive advantages,) and my numbers actually look way too low.

3. OK, so it could all be done on the cheap with lead-acid batteries, crappy motors & controllers, maybe even kit-style. Just make the components and sell them. Its still going to be close to $10k in parts, so it would have to sell near $20k, and it just wouldn't be a good enough product or doable enough as a project for people to sell 4 units a month. Maybe, but man that is a low number. Suppose you can figure out a way to sell 4 of them (or of anything, really) every month and make $10k gross profit on each one. That's $500,000 a year, and it isn't going to support more than a couple of guys and the owner of the business, so basically you're looking at a very risky, capital-intensive business venture designed to produce, at best, a shoestring operation that won't really make any money.

Anybody who thinks I'm nuts with these numbers and realities, by all means get started and good luck to you. I mean that with all my heart. The world needs you to succeed, too. I will also be the first person in line for a job at such a company, but I just can't afford to own or start one. Yes, I want to change the world of personal and family transportation, and I'm not saying cottage manufacturers aren't cool or the way to do it, but gosh, look at the odds against them. For me, its going to be just a hobby until someone can offer me a job in this (not yet really existent) industry and not just an "opportunity..."

So, a short answer is: If it were me, $35k, but it doesn't matter. If the price is right for the business, 4 units every month will not be an achievable sales target. If the price is right for the market, (like $10k for the Trilectra, for example,) then the company probably isn't viable. Remember, Corbin went under, too, as did HMV, Vanguard, and many others, most of which had relatively sorted designs in true small-volume production for a low enough price to sell more than a handful of units. More than that, I think the "today" part of your question is another hard stop. Gas is cheap and nobody is buying ANYTHING that they don't really need right now. Who really needs an electric motorcycle?

How's that for a rant? Even remotely close to the kind of answer you were looking for? :shock:
 
Has anyone rode one of the Trikes built by this guy:
http://www.ffrtrikes.com/electric_trikes

They look fast, Although i think i prefer a hub motor just for asthetic reasons though the motor mount he machined look pretty sweet.
 
find the Tadpole trike you like then add body ...

http://www.rbr.info/store/rbr-aergo.html

My concept would be ...

4010007311_35e42be550_b.jpg


http://www.goblinmotors.com/html/recumbent_bicycle_and_tricycle.html
 
Nice body here ...

ELIO_middle.png



Also ... Three-Wheelers Will be Eligible for DOE Funds

http://puregreencars.com/Green-Cars-News/markets-finance/three-wheelers_will_be_eligible_for_doe_funds.html
 
todayican2 said:
Looks slick Tom!
Whats the track width up front?

It depends on what day you ask.. :)

Seriously, I'm trying to get aftermarket CroMoly arms with heim joints now, and what I can find will determine the track width. FullFlight used to make them, but they don't as of this spring and I missed them on closeout. If I could find stock width arms, I would go with that. I want the CroMoly for weight savings and strength, and the heim joints for adustability. It is turning out to be a little bit of a challenge.

Then, on my chassis, they will be 8" apart, because I found an 8" mini buggy steering gear. Stock length arms would be 15" each side from there to the wheel flange. That's a 38" track. I found a pair of ultra-cool custom-width Douglas wheels in my rare Suzuki bolt pattern from a quad drag racer- they are 10x4, and came mounted with nearly new genuine DOT-approved 3.50x10 scooter tires. This setup is PERFECT for me, and weighs an astounding 14.5 lbs for the pair! This is an ideal and street-legal road setup, and with these narrow tires, the required body width at full lock is minimized, with the max overall front width "straight ahead" being about 42" between the outer wheel flanges. The front rubber footprint would be about 40" wide. Going with +1 or +2 arms would add the corresponding width to the package. It wouldn't really bother me either way, but I have to know before progressing further because the package goes entirely inside the bodywork.

Lately I've been working on the hubs and front brakes. I have a set of Wilwood NS1 two-pot calipers that will require some trimming of the stock hub, and then an adapter plate fabbed to mount them over the slightly larger rotors from an LT450, which will bolt onto my LT250R hubs. This is an upgrade that's been done before, and it apparently works very well. My unique problem is getting the normally handlebar-mounted quad front brake master cylinder (and the normally foot-operated rear master) to mate-up with the brake lever actuators on the unusual Honda Odyssey airplane-style yoke I'm using.

Its been lots and lots of little, and sometimes formidable problems, but I'm happy with how its going. I'll get the blog going when things are less in flux and I have some of the actual fab work behind me and documented. The good news is that while the weight numbers keep moving around some, I still think I can keep this thing within a whisker of 400lbs. Even more exciting, I have taken the pilot (me) from 247lbs to 184lbs in the last 8 months, with a "design" target of 175 that will be very nearly if not actually achieved. That takes a lot of pork out of the machine, and makes such a huge difference for me in so many areas, I could throw the EV in the garbage and still be way ahead from doing this project.

Thanks for asking Tom, and BTW, I like the new electric bike you're building for Mark's motor. I'll be watching how you make it steerable.

TomA
 
Its good to see it taking shape Tom A!

A few thoughts:

38 or 40" in my opinion is too narrow. I know its not good to hear, beleive me I diddnt want to hear it, but as you may remember, I know the results of too narrow first hand :-(

Granted the batts will make the balance right and will help keep the weight between the front wheels, and the cowling needs it narrow, but I wouldent personally go less then 50" (or physically lock the steering at a very narrow steer angle)

also, there is a fairly popular 14" buggy rack out there for about $99 just google or ebay "14" buggy rack"

On the bike, I got an old Yamaha for the forks and the damn brakes seized. so I now need a new set of forks :-(
 
I think about the track width probably more than anything else.

There's a fair amount of design engineering information available to look into this, and I'm reviewing it thoroughly. I'm planning to do several things that are absolutely necessary to manage this issue, and I'll be verifying all that with measurements, math and testing:

1. Put the longitudinal cg at 35% or so of the wheelbase, and keep the vertical cg as low as possible- just 9" off the ground if I can do it.
2. Keep the tire contact patches small, and make sure I have a good enough suspension design that they are really stable, with lightweight components, a roll center very close to the ground, proper Ackerman steering angles, and no bump steer.
3. I was trying to avoid building a 1:3 scale model, but its more and more likely that I'll have to do it to really get the relationships and figures I need to finalize dimensions and mass estimates.

We are playing at opposite ends of the spectrum a little, Tom B, and I kind of envy your process. You are actually getting rigs welded together quickly, learning a lot, and moving on to the next one. I have chosen a relatively tough target (for a non-engineer with no staff and little money) that has created a long list of small and not-so-small problems to resolve before I get it all together. Its a fun challenge and I really do like what I'm doing, but man it would be nice to have something to ride around in faster. Must be very satisfying for you and the guys.

Anyway, I need to know my track width is safe and appropriate before the design moves to construction, and I understand and share your concerns about it. I'll be doing the homework on that, rest assured...

TomA
 
todayican2 said:
A few thoughts:

38 or 40" in my opinion is too narrow. I know its not good to hear, beleive me I diddnt want to hear it, but as you may remember, I know the results of too narrow first hand :-(

An idea or two here to help understand your experience, and get some principles into the discussion of track width and stability.

First, the longitudinal center of gravity on a reverse trike should be within 35% of the wheelbase from the front axle in order to give the vehicle the best tip resistance. That's based on multiple research studies from Walter Korff to Paul Van Valkenberg to Pierre M. Ethier.

Second, the vertical center of gravity must be no higher from the ground than it is laterally from either of the imaginary lines between the contact patches of each front wheel to that of the rear wheel. Those are the lateral tipping axes of the vehicle, and if your cg is higher off the ground than it is laterally from that line, the vehicle will tend to tip and not to slide. There's a ton more to this, including slip angles, traction, etc. etc, but those are the basic ideas.

Take a look at a brief overview of this from Professor Ethier's website:

http://www.clevislauzon.qc.ca/Professeurs/Mecanique/ethierp/3-wheels/stabil1.htm

There's also a full explanation of his calculations and margin of safety determinations on that site, and a comparison of his work to the the work Paul Van Valkenberg's group did for the DOT nearly 40 years ago, but its all in FRENCH! I have a friend that might be willing to work through some of that with me, because I really do need to know it. For our purposes here, though, the brief overview is sufficient.

So the key to stability in reverse trike designs is to have the cg near the front wheels, and low. Look at the Duo-Delta, or the Tri-Magnum, or even the T-Rex, and see where the weight is. Then look at your Skeltin trike, (not to pick on it, but it has a serious design problem with the weight distribution,) and you can see the problem. Yes, a much wider front track does tend to fix that a little, but the real stability issue for that vehicle is how far rearward the cg is. There's no way to fix that without a super-wide front axle, which is probably why your intuition is exactly correct based on the experience you've had with your vehicles. Your V-Twin Reverse Trike was considerably worse in this area, while the diesel hybrid was somewhat better, and could maybe have made do with the front track it had, but it all depends on the cg placements. Anyway, that's the idea of it, without any of the math that really proves it all up, but it does seem to jibe with your experience, especially when looking closely at your vehicles.

For myself, I'll get all the way to the rather tedious calculations soon enough, but for now the conceptual explanation gives me excellent guidance on what to do to optimize tip resistance- First, get the weight as low as it will go. Second, get the weight balanced as closely as possible between all 3 wheels (true balance there would create an ideal 67/33% F/R weight distribution, and take care of any left-right differences in tip resistance,) I can use the pilot's location to balance the vehicle weight precisely, because I'm making a limited purpose trike for myself. At that point I will also use the available front track and wheelbase options I have in the design phase to optimize performance and safety.

TomA
 
Excellent points Tom A. I agree that the previous designs the balance was always an issue, even the tri mag, but alas, this is one of the reasons I LOVE electric trikes :) (Batteries can cure a lot of balance ills) Ill review those links soon.
 
I say 47" wide front wheel track for a electric human tadpole trike ... will fit in van or pickup

68-70" wheelbase 10-13" seat height

a little larger than this ...

http://fr.myspace.com/index.cfm?fuseaction=vids.individual&VideoID=6533800
 
Four feet wide? That's a lot! :) I'd prefer something under 36" (less actually, to keep the width narrow enough to fit thru a house doorway, or anywhere else a really big wheelchair might also be able to fit, like bike paths and other multi-use ways. Four feet would definitely prevent use of most canal pathways around here, as they have posts to prevent larger vehicle entry in many places, so cars don't try to use them as shortcuts (some still do, where they are not blocked physically from doing so).

Four feet would also prevent use of most bike lanes, and force me to ride in a traffic lane no matter what (otherwise, I'd be only partly in the bike lane and that'd get me hit for sure, vehicles clipping the wheel sticking out into "their" lane). Only in a very few places, for very short lengths, are any bike lanes around here wider than three feet. Most are not even wide enough for *any* trike, and some are not actually wide enough for a regular *bike*, yet are actually marked as bike lanes (when in reality they're just shoulders someone has "cleverly" added bike lane markings and/or signage to).


Personally I'd have a longer wheelbase than 70", but I'd be aiming for a cargo bike with pods between the seat and the rear wheel, as well as smaller ones alongside it.

My existing CrazyBike2 is longer than that, and although it would not have to be if I simply had the front wheels as tadpole trike config to either side, I don't want my legs out farther in front than the wheels are. Just bothers me. :) Plus I really want to put the cargo pods as a single larger pod between the seat and wheel, so that all of the weight is sprung and between the axles instead of some behind the rear one.
 
I think weve begun to to discuss 2 different trikes, the ones Tom A and I are working on are highway going electric only jobs.
 
Yup, seems there are two different project camps, basically divisible into- "electric motorcycle-class trike" and "electric HPV-class trike" talking in the same conversation.

Its very interesting that the many of the lighter class vehicles seem bedeviled by unstable handling and other control problems, but it isn't terribly surprising. Almost any steering design will work as a pedaled bike, trike or even 4-wheeler, especially a heavy thing that can't be made to go very fast. Since most of them have fixed, unsprung spindles, "suspension" design is mostly irrelevant other than fixing correct camber and caster. Of course, if you electrify one of these things and it starts going 45mph+ instead of the 15mph you can manage peddling, it will be a real handful...

The linked video to the Blue Anomaly is instructive- its really barely steerable, with a huge turning radius, such that when the pilot rolls into the alley at the end of the clip- he's stuck, he can't turn around or back up, and he has to get off. I'm not trashing the design, its fine for what it is, just pointing out that when your vehicles are that slow and light, you can get away with a lot more in terms of stability and control compromises. The velomobile crowd has discovered precisely this set of problems as they go faster and faster. Their trikes are often very marginal for road use, with twitchy handling, huge turning radii, and no suspension being the rule with them.

That's not what I'm looking to deal with at 60mph+ on a public highway. What todayican, I and others are doing is at the other end of the continuum between bicycle and motorcycle. These vehicles are 400-1200lbs, will do highway speeds, and are licensed as motorcycles for road use only- no bike paths or converted rail trail riding allowed. My current trike is actually the lightest EV I will probably ever build- the next one will be automobile-class, and weigh over 1500lbs.

Still, it would behoove anyone doing one of the lighter HPV-class trikes to take a good look at the design and engineering issues of stability, tipover resistance and control that the motorcycle-based trike engineers have been working on for more than 40 years now. That just isn't done enough in the trikes I've seen in the smaller class.

TomA
 
Well, the Myers Duo. This will be interesting. Absolutely nothing about this car anywhere except the mockup photos and interior Photoshop drawings on the website.

On the merits, this car looks like the wheelbase is a little too short, the front overhang too short, with too little mass ahead of the front wheels and the occupants placed too far rearward. It just looks tippy, from my studies of 3 wheel designs. I wonder what it will weigh, and whether having two heavy people riding in it, (or worse, one really heavy person) sitting so close to the rear wheel will change the Cg so much that the car has handling (tip over) issues. The Corbin Sparrow apparently had a some flip over problems, too, and it has almost half of its battery mass ahead of the front axle, and it has less passenger mass to vehicle weight than the Duo. It will be a lot more difficult to make the bigger car as stable. The company's statements in the absence of a vehicle, or even a detailed spec also make me very skeptical. The cabin will be made to accommodate "95th Percentile Male" occupants, which is about 6'2" and 250lbs. I find it hard to believe two men that size will ever fit in it, and if they do, that it won't be a big flip over risk, especially at the 75mph it is supposed to go. Whatever, they are making the Sparrow/NMG, and seem to be able to raise money, and I wish them the best. It could be a really, really cool thing. I personally think they are flirting with some serious rollover and control issues given the objectives of this design, but what do I know?

I note the classic "no-delivery-date-because-the-car-doesn't-yet-exist-but-we're-selling-it-anyway" business strategy. In the FAQ on their website, it says the NMG2 is "due out summer of '09." I guess they forgot to check that section when their September press release announced that production "is anticipated in the fourth quarter of 2010." I know these efforts are very difficult and delays are inevitable, but why do companies like this INSIST on pumping out hopelessly optimistic non-information? These predictions are ALWAYS wrong. Myers is not alone, either. Almost the exact same game is going on at Arcimoto, and GM for that matter. I am also behind on building my ONE trike, so I really do have an idea how it goes, but I'm not promising anybody anything, taking their down payment or investment money, and hoping my dream scenario for how all this work is going to be financed, completed and tested somehow materializes into reality. So, putting pictures up of the new hot vehicle I can put a deposit on now and drive in a year and a half is fun, it borders on a right of passage for those passionate few involved in actually trying to make it happen, but I must say I'm pretty immune to confusing it with available products. I'll take a good look at the Duo when I can touch one.

One thing is for sure about their production schedule, though. Without a working prototype, there is really no time to make real changes between now and production in Q42010 should the design need revision. It had better come out right the first time, or the customers are the ones who are going to find the problems, or- and this is most likely- it just won't enter production about this time next year.

We shall see how it turns out...

TomA
 
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