Science fair Ideas....

weekend-fun

weekend-fun

New Member
Hi...!
I am wanting to do a project for the science fair, and i want it to involve motorbicycling.
My first plan was gas or eletric? witch is better?. I also thought about doing eltrico-magnet thing
(as listed in a prevouis thread: http://motorbicycling.com/f28/never-attemted-plz-look-9718.html)
If you had any ideas i'd like to hear them :)

(another thing is that i usally pay for the stuff on my iwn, but for the science fair my mom will provide the $$$$ :) Lucky ME)usflg
 
Converting your motor bike to run on ethanol might be a science project.
I think it would only require a larger main jet in your carburator. (Do a search on
alcohol or ethanol and see what other members have done)
Home depot sells a veggie based 2 stroke motor oil.
Your bike would be "Fossil Free".

Some current formula 1 race cars use a KERS system; converting braking energy to stored power for later acceleration. Some generate current to charge a battery. Others spin a flywheel with braking power. The flywheel system might not be too hard to add to a bicycle, utilizing a friction roller to transfer the power.

When I received my motor kit, I asked my teenage sons if they wanted to use it in a science project but they were not interested.
 
Here ya go... laff
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I remember in my fifth grade science fair what I did was I took apart an old 4 stroke Briggs&Stratton off a pressure washer and brought that in. Think I used a poster to show the four strokes, what each one did, and how the internals of the engine worked. My brother helped me out with it, but everyone at the fair thought it was so cool, and I learned how an engine worked.
 
weekend-fun said:
Hi...!
I am wanting to do a project for the science fair, and i want it to involve motorbicycling.
My first plan was gas or electric? witch is better?. ...
Click to expand...
When I was building my motor-bike, I did a web page comparing the cost of operating a gas-engine (4-stroke) bike compared to an electric. The gas-engine was considerably cheaper both to purchase initially, and per-mile of operation. The Bionx page has figured for their electric setups and you can figure out what gas engines cost.

{-this didn't surprise me too much because if electrics were really cheaper per-mile, then commercial trucks would be electric instead of fuel-burning, and none of them are-}

Lots of people love to claim that electrics "don't pollute as much" but there's simply no proof of that. It is true that batteries can be recycled, but there's inefficiencies involved-both ecological and financial.

The only definite claim the electric bike motor setup could rightfully lay claim to was lower/easier maintenance.
~
 
Well, you could say that an electric bike is better for reducing air pollution. Global warming is a big "hot button" these days.
 
Well... not to stray too far from the topic, but the question with electrics is - where does the power come from? If yer solar and have a charging station it's all fine and good, but if yer just using grid power then its coal or nuke (unless it's hydroelectric ofc)...

Having one less internal combustion engine sounds great, but the power still hasta come from somewhere.
 
True, but I was under the impression that there's still a significant increase in overall efficiency. I found this on Wikipedia:

An EV recharged from the existing US grid electricity emits about 115 grams of CO2 per kilometer driven (6.5 oz(CO2)/mi), whereas a conventional US market gasoline powered car emits 250 g(CO2)/km (14 oz(CO2)/mi).[14]
Click to expand...

In countries like Canada that have a large hydroelectricity infrastructure, it's even better.
 
Yep, and that's good stuff too - thanks :D

It still gets weird as there's other environmental impacts than just CO2, I'm not by any means tryin' to harsh on EVs... there's just more to the story is all ;)
 
Hi 42Blue15 - I have to wonder where you got your figures for electric vs gas. If you’re talking about a Bionx hub motor with Lithium, well that’s a pretty expensive way to go. On the other hand, a home-built non-hub setup (friction, chain or belt) using a Chinese electric motor can be very cost effective. My electric front wheel drive (described on page 2 of http://motorbicycling.com/f9/controller-relay-9929.html as well as Endless-sphere.com • View topic - 3 speed front wheel drive e-bike ) cost me less than $175 for all new parts: motor (Unite 1016Z3 350 watt), batteries (2-12ah 12v SLAs), sprocket, chain, controller, throttle, wire and connectors. I fabricated the racks from scrap and built it from 2 give-away bikes. Add another $15-20 for a charger and it's still under 200 bucks for everything. I think it would be hard to do a 2-cycle China girl for that, never mind a 4-cycle. Plus it starts every time. I set it up so it has 3 speeds for more power on hills and speed on the flats. I've done 15 miles of hilly riding and had battery left. It freewheels so I can pedal easily to extend the range as much as I want. To tell you the truth, I don't have a tough enough butt to ride a bicycle more than an hour or 2 at a time anyway.

Maintenance and operating costs are next to nothing. Charging the batteries after a 10 mile jaunt uses less than $.10 of electricity. That’s 275 mpg at today’s gas prices. Yes I’ll have to replace the batteries someday but at under $40 for the pair that’s not going to break the bank. Of course they can and should be recycled. Also, I think “they” are moving forward on battery technology, so performance is going up as prices come down. I think the short-commute future is with plug-in electrics – car and bike. That might be a good point to make at a Science Fair - jd
 
BarelyAWake said:
Well... not to stray too far from the topic, but the question with electrics is - where does the power come from? If yer solar and have a charging station it's all fine and good, but if yer just using grid power then its coal or nuke (unless it's hydroelectric ofc)...

Having one less internal combustion engine sounds great, but the power still hasta come from somewhere.
Click to expand...

Thats why i wanted to do solar....completely green.
But its lookin' like i might have to just compare eletric vs gas vs car vs normal bike :p
 
jdcburg said:
Hi 42Blue15 - I have to wonder where you got your figures for electric vs gas. If you’re talking about a Bionx hub motor with Lithium, well that’s a pretty expensive way to go. ....

Maintenance and operating costs are next to nothing. Charging the batteries after a 10 mile jaunt uses less than $.10 of electricity. That’s 275 mpg at today’s gas prices. Yes I’ll have to replace the batteries someday but at under $40 for the pair that’s not going to break the bank. ....
Click to expand...
The problem with doing a comparison of e-bikes using SLA batteries is that SLA's are so heavy and have such a low energy storage density that (at the time I did the web page) none of the better kits even offered SLA batteries at all. Using SLAs immediately limits you to very short distances, as SLA's are the most-easily damaged by deep discharging.

I got my e-bike figures off of the BionX site, because that was the ONLY site that tried to give real-world performance figures for what they were selling. BionX tries to explain how many miles you'll get per-charge, and how many discharge cycles you will get before needing a new battery. You need to know that stuff to compute the real costs, and nobody else knew them, and no other vendor sites gave them.

I used the two battery types that BionX offered, because that was all I had real figures for.

My info showed that gasoline would need to rise to around $14.50/gallon before EV's would become economically justifiable.

Someone did post a link to an electric scooter that could come very close to the cost-per-mile of a gasoline setup. The scooter used lead-acid batteries but it only had a range of about 30 miles, and it weighed over 300 lbs. The long recharge times and the lack of pedals (the scooter being too heavy for them anyway) drastically affected its practicality. Yea if you only had to go 20 miles total a day it would work great--but then, the question becomes "if you buy the e-scooter to save money on gas, will you ever recover the purchasing cost of the e-scooter by gasoline savings?" and in most instances, the answer is "no". Most people who buy motorcycles and claim it's to "save gas compared to driving their car" will never recoup the cost of the motorcycle ownership by gasoline savings.

I'll repost that web page if I can find all the stuff that was on it.
~
 
Hi 42blue15 - I can't really argue with your analysis as I don't know what figures you or Bionx used. Because we are talking about a science fair project, it would be good to use the scientific method, that is, quantifiable data obtained in a reproducible manner analyzed without bias. Last month I paid $60.70 for 326 kWh of electricity from the grid. That’s $0.186/kWh. My 6 amp 12V battery charger says the current draw is 1.1 amps at 120 volts, which is 132 watts or 0.132 kW. Normal charge time is 2.5 hours for an average 10 mile ride. That’s for the 2 12v 12ah batteries connected in parallel for charging. Charge time can vary slightly depending on headwinds and load but hasn’t exceeded 3 hours. 3 hrs X 0.132 kW = 0.396 kW. 0.396 kW X $0.186/kW = $0.073 per charge in “fuel costs.” That’s $0.007/mile for a 10 mile ride. If gas is $2.75/gal, then 2.75/0.007 = 392.8, or the equivalent of 393 mpg. However that doesn’t factor in depreciation on the batteries. I paid $18 each for them. If they last 100 cycles, that’s $0.036/mile for the pair for each 10 mile ride. I can’t speak from bicycling experience about that many charges, but my Black & Decker battery-powered lawn mower has 2-12v SLAs that have at least 100 cycles on them, so that is not an unreasonable assumption. $2.75/(0.036+0.007) = 63.95 mpg equivalent. 200 cycles would give 110 mpg. Lithium batteries are reported to have a 1000 cycle life, so although they are more expensive to purchase new they may be a better long term purchase, in addition to being 60% lighter. BTW, my total conversion including SLA batteries, motor, racks, wires, etc added about 30 lbs to the 40 lb bike, so it’s nowhere near 300 lbs - jd
 
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