Streamlined gasoline-ICE microcar/tadpole trikes

[The Toecutter]

Here's one that caught my interest:

https://www.youtube.com/watch?v=jOPvnh0k05g
[youtube]jOPvnh0k05g[/youtube]

Claimed 120 mpg at 70 mph and it seats 2 people. If it had some wind tunnel time to sculpt its shape, I bet drag could be cut by more than half. The engine could likely also use some tuning. Considering it seats 2 people, this efficiency isn't terrible. But overall, I think 300 miles per gallon at 70 mph is possible with some optimization.

This next beauty, a single-seater, was designed by Paul Elkins:

https://www.youtube.com/watch?v=2REj9LSsIvE
[youtube]2REj9LSsIvE[/youtube]

Without the custom aerodynamic body on it, he reached 57.3 mph on a one-cylinder 185cc engine. For certain, this vehicle's fuel economy is going to end up in the triple-digit MPG range in normal operation with that body installed.

According to a later video, it weighs 322 lbs complete(including body):

https://www.youtube.com/watch?v=LfKW0ARjlI4
[youtube]LfKW0ARjlI4[/youtube]

He describes it as "squirrelly" over 50 mph. Top speed claimed is 62.2 mph.

If it had the aerodynamics of my Milan SL velomobile, thousands of MPG at highway speeds is theoretically possible, even with its current weight and engine. His won't be that efficient, but it is still easily an order of magnitude improvement over most cars.

I really like his build, because it has many similarities to what I'm trying to do with my KMX trike. Except his is gasoline, and mine is electric/pedal hybrid. And his is much heavier a vehicle. I'm keeping to an intended 100 lb vehicle dry weight limit(ready to ride, including batteries, but no rider/tools/luggage/ect). I might go slightly over, but no more than 120 lbs for certain, otherwise the pedals aren't of much use if the EV drive system fails. Downhill, in both my custom KMX build and the Milan, I've been much faster than 62.2 mph. The Milan gets kind of scary at anything over 45 mph but has been almost twice that and isn't as bad as it seems once you're used to it, but my KMX feels deceptively stable downhill at 60+ mph on good roads(albeit, this was tested before I installed rear suspension and extended the wheelbase). In both vehicles, the brakes aren't yet up to the task, but the KMX may be in the future. The KMX feels fine at speed, and the previous build had no problem holding 45+ mph using the motor, which is why I say it's deceptively stable, because the brakes/spindles/wheels/tires it used were all ill suited to that use case. A spindle did eventually fail after hitting a pothole at 40 mph, so things can seem fine, then suddenly get very scary, or worse...

I'm sort of saddened Paul isn't going to perfect his build or make another. A longer wheelbase and a refined body design could really go a long way. I think his vehicle with that engine and low mass has 130+ mph top speed potential if he really sat down and decided to optimize everything, especially the body, and tuned the engine for a modest power boost, and it would do such while getting stellar fuel economy. Even as is, his build is damn impressive. I emailed him last year and never heard anything back though.

 

[ZeroEm]

Don't think will go back to ICE. Do like some of the deigns. Want something easy to get into.

 

[The Toecutter]

I'd consider ICE if I could get a sufficiently powerful engine/gearing combination that would be lighter than a comparable EV system at an affordable cost, but it really doesn't exist. When you get down to microcar-sized or smaller vehicles with extremely good aero(on par with a velomobile), a BEV is actually the lighter solution for a given amount of performance/horsepower/expense, than is an ICE system. A 49cc complete ready-to-use ICE system would weigh more than and make less power than the hub-motor equipped 1.5 kWh BEV system I've been using, UNLESS I spent $XX,XXX building up a high-maintenance single-use racing moped engine in which case the weight difference between the two would be very close if I dropped the displacement to something smaller.

If I spent comparable money to my current EV KMX build, instead on an ICE system build that could deliver similar performance, the thing would end up well over 150 lbs, and would be a less reliable system overall than the BEV. It would be nice to only need a 1-gallon tank and get like 500+ mile range doing 70+ mph on the highway though, but there's no real need for that, and this perk is not worth the design compromises that will be required to attain it.

For such a small/aero vehicle, the EV system ends up being the superior choice in almost every relevant metric. It flips a bit when going to much larger vehicles like cars, but even there the gap is rapidly narrowing, and I'll readily argue that an affordable lightweight EV car with 200+ miles range was still possible 20+ years ago.

 

[ZeroEm]

Gm's EV1 with out lead batteries.

Remember seeing one in the 1980's in OKC, OK USA

 

[red]

Being that low and that small, I seriously question the need for extreme high speeds, and even the need for freeway speeds. When riding a full-sized motorcycle, too often you will get cut off by drivers who simply, truly, did not see you and did not look. From a real-life safety aspect, taking one of these mini-vehicles out onto a freeway would be very hazardous to your health.

A very small motorcycle power plant (complete with a transmission) would be more than enough motivation for these "city" vehicles, and extremely efficient. A Honda Grom gets 100 MPG, or close to it, and it would certainly do better in a streamlined vehicle. You can probably find even better MPG from commercial small motorcycle units, with the advantages of competent engineering from the start, and reasonable parts availability.
All IMHO, of course . . .

 

[goatman]

as much as i like the tadpole trike/velomobile style for getting around (i think it would have the best chance of getting people out of cars. )
our north american cities just arent designed for them to co-exist with cars

im always looking for another used one for the rainy day rides and long cruises
i really like euc's because theyre so convenient when i head into the big city but the legality of them is very grey

Just look at our North American society right now, present day and it will have to be a Mad Max Zombie Apocalypse event otherwise known as The Great Reset for that to happen.

 

[BalorNG]

I'd consider ICE if I could get a sufficiently powerful engine/gearing combination that would be lighter than a comparable EV system at an affordable cost, but it really doesn't exist. When you get down to microcar-sized or smaller vehicles with extremely good aero(on par with a velomobile), a BEV is actually the lighter solution for a given amount of performance/horsepower/expense, than is an ICE system. A 49cc complete ready-to-use ICE system would weigh more than and make less power than the hub-motor equipped 1.5 kWh BEV system I've been using, UNLESS I spent $XX,XXX building up a high-maintenance single-use racing moped engine in which case the weight difference between the two would be very close if I dropped the displacement to something smaller.

If I spent comparable money to my current EV KMX build, instead on an ICE system build that could deliver similar performance, the thing would end up well over 150 lbs, and would be a less reliable system overall than the BEV. It would be nice to only need a 1-gallon tank and get like 500+ mile range doing 70+ mph on the highway though, but there's no real need for that, and this perk is not worth the design compromises that will be required to attain it.

For such a small/aero vehicle, the EV system ends up being the superior choice in almost every relevant metric. It flips a bit when going to much larger vehicles like cars, but even there the gap is rapidly narrowing, and I'll readily argue that an affordable lightweight EV car with 200+ miles range was still possible 20+ years ago.

A *parallel* hybrid using 49CC water-cooled motor and overruning clutch, geared just so to maintain your most efficient cruising speed (both when it comes to motor efficiency and aero) is literally the best of both worlds.

High efficiency at cruise, can still regen with a hub motor and use it a generator (RECHARGE your battery at highway speed!), great acceleration and torque control at low speed, very simple 'single speed' transmission (not gearbox losses).

But you'll need to solve the problem of VERY noisy high-rev 49cc motor inside the shell, let's you lose your hearing in short order.

 

[ZeroEm]

Like this one

http://angloisrael.com/reversetrike/xr3-hybrid.html

I agree with everyone on the not as safe as a large car or truck. Here it's not safe in a large car. I don't drive the highways in town anymore in my car.

Want something bigger than a velomobile but not as big as above. Take the middle ground and run moped wheels, stronger than bike but not as bad as car wheels.

Then their is the 2005 super slim two-seater Tango T600
https://siamagazin.com/the-super-slim-two-seater-tango-t600-tiny-electric-car/

 

[SlowCo]

Here's one that caught my interest:

Great build from my fellow countryman.
He also built a solar electric velotrike: https://www.wmzprojecten.nl/solar-quest-elektrisch-ondersteunde-velomobiel/

 

[CONSIDERABLE SHOUTING]

I'm mostly interested in doing these little weird 3-wheelers for their possible acceleration and top speed characteristics. I just wanna make something that makes me say "Who needs a Tesla Plaid?".

Here's one that caught my interest:

Hey Toecutter! I needed to shoot you a message to see what was up, you suddenly went dark.

Like this one

Blessed XR3. We only JUST lost the creator too, he was still designing something until he passed.

 

[The Toecutter]

A *parallel* hybrid using 49CC water-cooled motor and overruning clutch, geared just so to maintain your most efficient cruising speed (both when it comes to motor efficiency and aero) is literally the best of both worlds.

High efficiency at cruise, can still regen with a hub motor and use it a generator (RECHARGE your battery at highway speed!), great acceleration and torque control at low speed, very simple 'single speed' transmission (not gearbox losses).

But you'll need to solve the problem of VERY noisy high-rev 49cc motor inside the shell, let's you lose your hearing in short order.

I've considered this, but it wouldn't happen in any vehicle I build that has bicycle pedals, because the pedals would be useless on their own due to vehicle weight.

But for a non-pedal microcar, this solution is ideal. Especially if the 49cc engine is a diesel. I haven't quite figured out how I would address noise in such a thing.

But the potential to get 1,500+ mpg at highway speeds is there. With a 5 gallon tank, such a vehicle could hypothetically get into a police chase where the speeds almost entirely exceed 120 mph and have enough fuel to out-distance an MQ9 Reaper drone. Really can't go wrong there.

Just look at our North American society right now, present day and it will have to be a Mad Max Zombie Apocalypse event otherwise known as The Great Reset for that to happen.

A) A "Mad Max Zombie Apocalypse" style event is actually mutually exclusive to, and IMO preferable to, a "Great Reset"
B) A "Great Reset" would likely mean a ban on our e-bikes to "conserve energy", while the rich continue to waste resources getting around via private jets and megayachts that guzzle hundreds of gallons of fuel per hour

Personally, I think the likelihood we get either scenario is low, at least in the near term. In the longer term, anything is possible. What is more likely is that gasoline shoots up to $10+/gallon in the USA and most automobile operators become priced out of using their vehicles, coinciding with economic collapse. THAT is where we're really going to need some real solutions, or it will devolve into either A or B. B should be rejected at all costs.

I'm glad I have my two velos to weather such a storm with. The trick will be to keep them from getting stolen, and to avoid being damaged/destroyed by careless automobile operators. I've already been hit 3 times in my machines, and got lucky that I wasn't hurt and that my vehicles weren't totalled.

Like this one

It is a good concept, but it has room for nearly an order of magnitude improvement via aerodynamics. I hate how everyone focuses on a certain type of aesthetics to the expense of ultimate efficiency. What a way to go against the entire purpose of the vehicle to begin with, while making it more expensive and adding to its operating costs, all needlessly. To it's credit, it is less baroque than most new cars at least, and was definitely a step ahead aerodynamically than say, the Elio or the ElectraMeccanica Solo.

I agree with everyone on the not as safe as a large car or truck. Here it's not safe in a large car. I don't drive the highways in town anymore in my car.

Want something bigger than a velomobile but not as big as above. Take the middle ground and run moped wheels, stronger than bike but not as bad as car wheels.

Paul Elkins built that "middle ground", IMO. Moped wheels of a given size are not much heavier than bicycle wheels of a given size, but they are a lot stronger. Having talked with suppliers of components I'm building my wheels with, all three wheels on my velo put together will add about 4 lbs versus the bicycle wheels I've been using. That 4 lbs will definitely be noticed when pedaling with the motor shut off though.

Then their is the 2005 super slim two-seater Tango T600
https://siamagazin.com/the-super-slim-two-seater-tango-t600-tiny-electric-car/

When I first saw this thing, my line of thinking was that with a lower profile ala VW XL1, and a focus on streamlining(lets say it looked something like the 2005 Volvo gravity racer), not only would it look a lot less ugly, but it could get double the range on the same battery pack.

But looking like a crappy pseudo golf-cart-car-thing the way it did, it definitely made a really cool sleeper of an EV given its acceleration. 80 miles range with lead acid batteries is impressive for the early 2000s, and this car did that. Double that was possible at the time with a greater focus on efficiency when using the same battery pack.

Hey Toecutter! I needed to shoot you a message to see what was up, you suddenly went dark.

Between my job and helping my mother, I haven't had a whole lot of free time. I've only recently been able to make progress on my electric velo build again because I finally cleaned up my basement bedroom and dragged it downstairs. My job takes up all my daylight hours, and working on it outside in the dark and when freezing was not viable.

Hydraulic disc brakes are in progress. After that, I need to set up a new e-brake for the rear by modifying a bicycle brake lever with a built-in parking brake using an ebikes.ca TripWire system. Then finish building up my new wheels.

Once I get all that out of the way and can test everything, I can finalize my next body design based on the Milan velomobile I purchased and get to work on that.

 

[The Toecutter]

More info on the reverse trike Paul Elkins built:

https://elkinsdiy.com/economical-reverse-trike/

His coroplast bodywork was a lot cleaner than mine, which would undoubtedly give an aero advantage.

If he did a scaled-wider Milan SL body over this with crumple zones, improved the steering geometry and chassis dynamics, and made use of some ground effects for downforce, this could be a very slippery bastard with the bare minimum stability needed for sustained high speeds. It can be the difference between a 120 mpg vehicle, and a 1,200 mpg vehicle, at least on the highway, on the same chassis with the same engine, even if we had a weight gain to 400 lbs. It could be much safer than a motorcycle and even many vintage cars if it were built to such a spec.

Now forget a 49cc engine in such a thing. Consider a 1.34L Hayabusa.

https://www.youtube.com/watch?v=C-Y-P0U1F3A

Take the weight penalty that and everything needed to accommodate it would impose. Maybe we're up to a 550 lb vehicle, that might in ideal conditions with a careful driver hypermiling it, yield 4-digit MPG fuel economy. Except you can squander fuel for hoonage when you want to, and probably still get low triple-digit MPG when you mix normal driving with copious amounts of racing. Tune the engine to make a bit over stock horsepower, and it would be a Dodge Demon slayer if you could get sufficient traction.

Unlike the motorcycle, wind resistance wouldn't be slowing your acceleration down at higher speeds(at least not nearly to the same extent as it would with a motorcycle). It would be delicious lunacy. Think of the trap speeds at the end of the 1/4 mile this could allow...

 

[ZeroEm]

Think it best to find a motor with high efficiency not a race engine.
Like this

Honda Rebel 300: More than 70 mpg claimed Honda’s single-cylinder Rebel 300 has impressive fuel economy at more than 70 mpg. Honda Honda's little single-cylinder cruiser is a fantastically fuel-efficient motorcycle. https://www.motorcyclistonline.com/...an Own,V-Strom 650: More than 50 mpg claimed

 

[CONSIDERABLE SHOUTING]

Don't forget, there's another component to the mileage game- you need an engine to have enough torque and force to move you without getting stressed or needing to rev high, as shown by the US winning the emissions race with Europe in the early 2010s since we had more displacement.
I'm hoping to find a little engine to build with to test this on soon, but I feel like the little 50-100cc engines are just, physically too small to get good mileage from since you'll be WOT all the time to move. But that's my VERY limited opinion.

More info on the reverse trike Paul Elkins built:

https://elkinsdiy.com/economical-reverse-trike/

Oh shit! I've been seeing this dude's projects for years and I never knew he had a site!

I hope to do similar; I'm trying to find a free engine (it's happened before!) to make some kind of rat bike soon. Even if it's an engine from a lawn mower. ESPECIALLY if its an engine from a lawn mower 8)

 

[Warren]

"Of all the recumbent bikes I've made, this was my favorite, and most used."

https://elkinsdiy.com/mwb-recumbent/

No surprise whatsoever. MWB with cranks near headtube, and above the front wheel, rock!

 

[The Toecutter]

Think it best to find a motor with high efficiency not a race engine.
Like this Honda Rebel 300: More than 70 mpg claimed Honda’s single-cylinder Rebel 300 has impressive fuel economy at more than 70 mpg. Honda Honda's little single-cylinder cruiser is a fantastically fuel-efficient motorcycle.

For such a small, power-starved vehicle, 70 mpg really isn't all that impressive. With the right streamlining and gearing, a full-sized car with a large engine could do the same distance on a gallon of gas.

This small motorcycle is using its low mass and low-displacement engine to get its fuel economy, and those are not the areas where there are the most possible gains to be made. The fact that a 3,000+ lb car seating 5 people can be made to exceed 70 mpg really says a lot in the context of this.

With that same engine, in a sufficiently streamlined vehicle of similar mass to said motorcycle, 700 mpg might be possible.

I bring up the Hayabusa engine because it will give the vehicle lots of added value. People often pay $XXX,XXX for that kind of acceleration performance in an enclosed vehicle like a car. So imagine what kind of market might show itself if an enclosed vehicle for < $1X,XXX allows one to compete with the fastest cars on Earth, while still getting triple-digit MPG, and having similar operating cost to a moped.

Don't forget, there's another component to the mileage game- you need an engine to have enough torque and force to move you without getting stressed or needing to rev high, as shown by the US winning the emissions race with Europe in the early 2010s since we had more displacement.

This is why the solution Balor mentioned is useful. You eliminate the transmission and replace it with an electric drive system, keeping the same mass or even reducing mass, while allowing the small engine to run at its most efficient point on the BSFC map. For a velomobile sized/shaped vehicle, this would yield quadruple-digit MPGs.

I'm hoping to find a little engine to build with to test this on soon, but I feel like the little 50-100cc engines are just, physically too small to get good mileage from since you'll be WOT all the time to move. But that's my VERY limited opinion.

For a velomobile-sized/shaped vehicle, such a small engine is actually plenty. Theoretically, my Milan SL should be able to maintain 100 mph on 4 horsepower. A 49cc engine could reliably be tuned to make double that. If the vehicle including rider and luggage weighed in at 300 lbs, that's enough power to move like a car, even going up steep hills.

For a bicycle, which has the overall CdA of a small car, such an engine may not perform so well at anything over bicycle speeds due to all of the air drag.

Oh shit! I've been seeing this dude's projects for years and I never knew he had a site!

I hope to do similar; I'm trying to find a free engine (it's happened before!) to make some kind of rat bike soon. Even if it's an engine from a lawn mower. ESPECIALLY if its an engine from a lawn mower 8)

I'm curious to see what you put together. Better do it soon, while you can still get parts, in the event that the supply line disruptions become worse. I'm in the process of stocking up on 7-speed parts, not just for backup parts for my custom KMX build, but also to use my other 26" 4T Leafbike motor in my Milan SL which will need to be converted from 9-speed to 7-speed to make it work.

 

[The Toecutter]

Here's an ICE-powered pedal tadpole trike that weighs 130 lbs, using a 49cc engine:

[youtube]Ils5EF-zWoQ[/youtube]

https://mpgtrikes.ecrater.com/p/18319401/bumble-bee-recumbent-tadpole-49cc

 

[BalorNG]

"Of all the recumbent bikes I've made, this was my favorite, and most used."

https://elkinsdiy.com/mwb-recumbent/

No surprise whatsoever. MWB with cranks near headtube, and above the front wheel, rock!

Yea, they solve the 'recumbent packaging problem' if you don't mind the small wheel... Still need fairly high one though. I wish there Kervelo didn't die, their coaxial gearbox would be SO useful to me right now

 

[ZeroEm]

70 mpg really isn't all that impressive

It would impress the police, officers, cops. Unless you riding in West Texas USA or the Autobahn.

 

[The Toecutter]

It would impress the police, officers, cops. Unless you riding in West Texas USA or the Autobahn.

Impressive would be getting 70 mpg while flying down the Autobahn at 160 mph. It's theoretically possible to design/build a vehicle capable of that.