Building a Better Motorized Bicycle

toyotaboy writes "Saw this in 'design news' magazine. It's a bicycle using an engine that looks like something pulled off of an R/C airplane. He uses a gear reduction system as well as a overrunning clutch to keep the engine running while stopped. Claims to get 20 mile range from its 1/4 gallon gas tank (80mpg). If you figure most engines like that are 30k rpm with 1:100 gear reduction, and an average bike rim is 26", you should get potentially 1,458,000 inches per hour, or 23mph! He goes on to say that similar devices in electric form (segway) fail because of their heavy 80lb weight and limited 10-15 mile range (and where do you recharge?) This thing can be filled back up at any gas station."

Comments

Great

[sulli]

So not only you get to breathe everyone else's exhaust, you get to produce your own via a two-stroke engine directly under your nose? Yucko.

Re:Great

[frdmfghtr]

Agreed. Plus, a small engine that can be strapped to a bike for some power-assist is nothing new. Look in the back of any Popular Mechanics, Popular Science, or any similar type of magazine, and I bet you will find ads for this amongst the ads for do-it-yourself helicopters, hovercraft, and motorized wheelbarrows.

Two other thoughts come to mind...

(1) If you're going to go the distances that might make this useful, chances are that you're not a periodic, recreational biker. Thus, are you going to really want one of these on your bike in the first place?

(2) If you ride short distances (around a college campus or in the neighborhood) do you want to have to smell the fumes and listen to the high-pitched whine constantly? These small engines generally don't have much in the way of mufflers or emissions control, so there's that to consider as well.

When I flew model planes, the fuselage was covered with unburned fuel at the end of a flight. I would presume that noise and unburned fuel have been taken into account in this design, but it's still something to consider. The designer probably went further than taking a big R/C aircraft engine and bolt it to a clutch and drivetrain.

Personally, I like the exercise and peace & quiet that comes with a nice bike ride, but as always, YMMV.

Re:Great

[t0qer]

I've seen so many negative comments on this I wanted to chirp in something positive, sorry for being mr optimistic :P

Anyways, first off I think at 23mph with the exhaust about 3-4 feet under your nose (Unless your a midget) you wouldn't have to worry about breathing in fumes. Site did say it has a centrifugal clutch which only activates the motor at a certain speed.

Also I've been reading a lot of comments about pollution too. Do 2 strokes really produce that much air pollution? I've heard that the opposite is true because since it is a gas/oil mixture the remaining exhaust resembles diesel more than 4 stroke exhaust, which just settles to the ground (Yay it gets into our streams and rivers though, which is why MTBE gas is banned in CA waterways)

I just wanted to play devils advocate, it looks like a really neat peice of engineering compared to those things I used to see in popular science.

Great idea

[x159]

But what about the sound - When I'm riding my bike, I don't want to listen to the constant loud, annoying drone of a motor.

Two stroke engine?

[gpinzone]

The environmentalists will be the ones having a stroke if this becomes popular. They don't even make 2 stroke lawnmowers anymore.

Re:Two stroke engine?

[Waffle Iron]

The most efficient internal combustion engines ever made are infact 2-stroke diesel engines, often used in ships and the like, these are large engines and it's well worth replacing them if a more efficient design exists.

To be precise, 2-stroke diesels work on a very different principle than a 2-stroke gasoline engine. They do not mix raw fuel and exhaust, and they have oil pans, so they don't have problems with spewing unburned fuel and oil. They also require an external supercharger to push air into the cylinders, so you won't find one on a chainsaw.

Moped

[fredistheking]

So exactly how is this different from a moped? 80 mi/gal for a moped is not that impressive.

--

Pretty cool, doesn't solve the original problem

[cubal]

It's a really good idea, but we are still going to run out of fossil fuels eventually (not to mention the pollution problem...

doesn't this just put off the inevitable a little bit more?

(although, I must say I wouldn't mind one... altho I 'm not sure how it would handle with the engine on the front wheel like that)

Bad for the Environment?

[trotski]

Some may think that a super efficient small engine is a good thing. I argue that point.

Although a small 2-stroke may put out much less greenhouse gas than a car or motorcycle, a 2-stroke engine of any size is very damaging to the air quality. A 2-stroke engine (such as the one on this bike) must burn large amounts of oil, it's simply the way 2-strokes work. Therefore, a lot more soot, and other impurities are blown out the exhaust. This is the smelly blue smoke you always see out the back of scooters, motorboats, chainsaws and other devices with 2-stroke engines.

While this may be a more efficient form of transportation, if everyone who rides a bike road one of these our cities would be far more smoggy and smelly than they are today.

Let me get this Straight

[Herkum01]

This guy has basically invented a light-weight moped?

American's despise moped's, they figure if you are going to get a a cycle you might as well get one that looks cool. That is why Harley's are so popular, becuase they look cool. I have a co-worker here that is willing to spend $5,000 dollar's every couple of year's to add accessories and get some improvements done on her bike.

While the idea is neat, it will not take off simply becuase of american culture, and it sounds like a moped.

Any gas station?

[Darnit]

What about any electtical outlet for the Segway? The thing goes 10-12 miles on $0.10 USD. That bicycle goes 10-12 miles on $0.25 USD.

Have you seen the pollution in growing nations that have cities full of 2 cycle engines on motor scooters? Damn man talk about stinky horrible asthma causing pollution.

How about this one?

http://www.austinev.org/evalbum/427.html

This bike is probably a little bit better than some stinky ICE bike. It also has the same range. Go figure.

Re:Any gas station?

[torpedo2k]

Next time you flip the light switch think of where the electrons are coming from... a "stinky" power plant. Of which 55% of the US gets from coal. People are quick to jump on the electricity bandwagon without thought as to where it originates.

Re:Any gas station?

[satterth]

And at the same time it is much easier to control and improve the emmissoins from a power plant than 3,000,000 automobiles scattered accross the country.

This is not the solution

[The Ape With No Name]

Two-stroke engines are great contributors to the incredible pollution of places like Dhaka or New Delhi. India is trying to get away from the ill-maintained motor scooters on gas/oil mixtures to hydrogen or, even more practical given the amount of animal manure available there, methanol. Discussion here with insight from a guy working in this problem. Fossil fuels just won't cut it because of the double headed monster of carbon fuel pollution and a multiplier effect of unmaintained equipment burning that same fuel.

Re:The Human-Powered Bicycle

[xtr_982]

<rant>
These things really make me mad. You have to be incredibly lazy to want one of these things. Why put an internal combustion engine on the most efficient form of transportation? With the level of gear reduction on most bikes, you can ride up any hill you can walk up... These must be for people who can't even walk uphill.
</rant>

Sometimes innovation for its own sake...

[dvd_tude]

... turns out to be just that. Taking a small, inexpensive motor and attaching it to a bicycle? It's a basically sound idea. That is after all how Soichiro Honda got started in the motorcycle business after the war. Putting the engine in the rim? Hey, another nifty idea, but not original: the Megola did that in 1922.

Okay, sometimes synthesizing old ideas into new ones can yield interesting results. At least it makes you think "hmmm, neat hack". I don't see this as a fine example of this. All that gearing and mechanical complexity of the clutches and gearset strike me as expensive and failure-prone: too many moving parts for what it sets out to do. It would seem simpler is better.

Then there's the question of intrinsic value. Mopeds and motorcycles are cheap for the utility and performance they provide when you compare them to today's overpriced yuppie-toy bicycles. You can find a used motorcycle for $1200 or so, and mopeds even less than that. Mileage? Well, my CBR900RR gets 55mpg, and I don't have to worry about looking good in Spandex. Pollution? Many have pointed out that even 2-stroke motors can be engineered to be quite 'green', such as Aprilia's direct-injected 2-stroke scooter using technology licensed from Orbital Engine Corp.

So, tell me why this is useful?

Re:noise and no emission control

[NeMon'ess]

Are the emissions worse than a Ford Explorer? If I ride this bike five miles to the suburban mall, and my neighboor takes his Explorer, with no other passengers, to the same mall, who pollutes the environment worse? Is the noise from this worse than that Explorer rumbling down the street?

My 80cc scooter gets 85 MPG and does 40 MPH

[Anonymous Coward]

I bought a used 1989 Honda 80cc scooter for $700 a couple years ago, which is probably less than what you'd put into trying to engineer a motor onto a bicycle. I weigh 160 pounds with jacket and helmet. The scooter weighs 140 pounds and will accelerate from 0 to 15 faster than pretty much anything out there. Of course from 15 on up it's completely gutless, but that's okay.

It'll do 35 easily all over Seattle and 40 on flat ground. Faster down hills. Its tank is a little over a gallon and I regularly ride it 95 miles between fillups. It has a wide flat surface down where your feet go that's big enough to put a big sack of groceries or a PC on, which I've done on several occasions (under carefully controlled test conditions, since loads are always supposed to be secured while riding around town, you understand).

It has a centrifugal clutch and no transmission, so its controls are basically the throttle and the front and back brakes, which are on the handlebars much like a bicycle's. The other controls are the ignition switch, turn signals and horn. It has a gas gauge on it, so I consider it feature-rich.

The scooter performs so well and is so incredibly economical and practical that for the first couple months I felt like I had discovered some amazing secret that would solve all of our energy and transportation problems, and that all I'd have to do was tell people about my experience with this marvelous machine and the world would be changed for the better.

Finally I stumbled across some pictures from Thailand or somewhere with an entire family, several suitcases, a dozen chickens, and a milking goat on a scooter putting down a dirt road and then it dawned on me: Yeah, these ultralight scooters are the most economical powered form of transportation that the human race has come up to date, but no one really cares. They want their SUVs and the oil to power them, and if we have to Shock and Awe a quarter of a million kids in baghdad to keep from having to shuttle a sack of groceries or a new NEC 19" monitor home on a scooter the way that millions and millions of people in "third world" countries already do, then that's just the way it'll be.

I really like my scooter though, and if I take it easy on it and don't try to beat the Camaro next to me to the other side of the intersection, it really does get 85 MPG and goes almost 100 miles on, uh, however much it is now, $1.50 or $1.70 or something.

Re:no place for bicycles, motorized or otherwise

[nochops]

So the bike lane is to blame for you being hit? Or you're to blame? What are you trying to say here?

If you were in the bike lane, and riding responsibly (following the law) I'm inclined to think that the person who hit you was at fault. Stand up for your rights. A bicycle does not belong on the sidewalk, it belongs on the road. If a bicycle lane is provided, all the better. Granted a bicycle could be unsafe on anything faster than, say a 45 MPH road, but otherwise it's perfectly safe and reasonable to ride on the road, as long as you follow the rules of the road. This means obeying stop signs and traffic lights, and stay as far to the right (in the US) as is practical for your own safety. In most states, a cyclist has the right to "take the lane" if he needs to protect his own safety.

Here is a comment I made on a similar story posted here recently.

Like the Segway, this thing doesn't belong on the sidewalk. If it can maintain the same speeds an avid cyclist can maintain (20-30 MPH) I could lve with it in a bike lane. Otherwise, it belongs in the road like any other moped/motercycle.

BTW, as if you couldn't tell, I'm an avid competitive cyclist.