Compressed-air powered bike

[Cigaro]

As I may have mentioned, I'm into building odd vehicles from time to time.

I've looked into this and I think it's actually possible, although maybe only practical as a commuter. I'm thinking a cruiser-style frame would be able to hold a big enough air tank - top speed would probably be in the region of 40mph and as in the eyes of the law it is not a 'mechanically propelled vehicle' there would be no need for plates, insurance, tax or MOT!

So...

- Am I crazy?
- Would you ride one?
- Should I build it?

[Zen Dog]

No, build a viable electric bike instead, then tell me what batteries and motor you used!

I'm looking it this myself, since the only thing available is scooters with rubbish performance and range. I want a real bike! But i'm having no luck finding a decent large brushless motor, and i havent a clue what the best batteries are these days, just that lead/acid are rubbish....

Surely a compressed air powered bike is going to be seriously inefficient, unless the air powers the rear wheel, rather than providing direct thrust.

Zen Dog
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Current - '94 VFR750FR (Dead), '00 VFR800FI, '10 600 Hornet - Previous - '11 CBF125, '10 Street Triple R, '92 MZ ETZ301, '05 TTR250, NSR125R, KMX125, "Honda" Win
My bike trip around S.E. Asia 2010/2011

[cqueen]

[Whosthedaddy]

[lukamon]

that would make me a bit nervous, slide off and sccccBOOM
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killa wrote: Im an ass man myself

[stinkwheel]

They use compressed air to power steam engines that don't have a boiler certificate. So, what you need is a small steam engine.

Why not build a bike with a single cylinder, 2-stroke diesel engine? Extra bonus points if you manage to have the pistons moving along the frame rather than across it.
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Cigaro]

That's the plan Stinkwheel - except I'll probably build my own.

How far can I realistically expect a big cylinder of compressed air to take me?

I'm still checking up on the legal situation - being able to ride this without any papers would be a massive plus!

[pwntifex]

Puttputtputtputtputtputtputtputtputt-putt-putt.


Good luck!
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the warped one: This is a follow up from the thread 'my willy hurts'

[stinkwheel]

[Paddy Blake]

I think it is a 'mechanically propelled vehicle' if it goes by its self and the
parts are moving by some thing other than your self.

Some one else might be better able to say this but I cant.
Do you think it is a mechanically michine with the moveing parts.
Dont let that stop you and see what you can do.
Best off luck with it.

Paddy.

[lilredmachine]

It is/would be a mechanically propelled vehicle. You are simply swapping the fuel/air and a bang to propel the piston with compressed air force.
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Bikes: too many, too much for one man to maintain anyway.

[TheShaggyDA]

Just having a quick ponder about the mechanics of a compressed air bicycle, I played with the idea of using one of those air drills for the "engine". With an air usage of (say) 400 l/min under load, and an average of 200 l/min capacity for a small compressor, you're going to run out of oomph very quickly.

I think electric is the next best alternative to internal combustion.
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Current: CB500 Previous: CB100N, CB250RS, XJ900F, GT550, GPZ750R/1000RX, AJS M16, R100RT, Enfield Bullet

[i:6e3bfc7581]But still I fear and still I dare not laugh at the madman...[/i:6e3bfc7581]

[Cigaro]

I think you're right, Shaggy, having thought about it.

I could always build a pulsejet engine and strap that on...

[lilredmachine]

It's a shame biofuel would require the entire world to be put over to growing oil crops, gotta love a more environmentally fuel that gives you more power.
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Bikes: too many, too much for one man to maintain anyway.

[Cigaro]

lilredmachine - I agree, and it is a shame too as biodiesel works brilliantly (I run my car on it).

[Robby]

This is where 2nd gen biodiesel, incredibly high yield crops (something genetecially engineered, that grows dense and fast), and a gasification plant becomes useful.

[Yoshi]

I am thinking about converting my car to run on vegetable oil. It's a 306 Dturbo S. These engines are meant to be good at it, as they're indirect injection. If I do it, it'll be run on a dual fuel system along with regular derv.

This is meant to be carbon neutral, as any CO2 you release in running the car is removed from the atmosphere when the plants to produce the oil is grown, as opposed to fossil fuels where it is released but not being taken in. That's the theory, not entirely sure if it's true, makes sense though.

The fact that oil costs 50p a litre from tesco or can be got for nothing if you get friendly with the local chippy (and filter it) might be the reason why as well.

I read somewhere that from this summer it's no longer going to be taxed for small scale users.
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Present: GS650 Katana - Getting ready for summer touring!
Past: TS50, RS50, ZXR400, LT80, TS250

[Cigaro]

[Didge]

All ready been done.........to a car anyway.

https://www.theaircar.com/

[Walloper]

hYDRAULICS WOULD BE A BETTER SYSTEM (FKIN CAPSLOK) Ahem..
As far as energy convertion losses goes, best to worst is: electrics, hydraulics, mechanics, then pneumatics.

The size of reservoir is not as important as the pre-charged pressure.
If you can Liquify the air you will have more reserve for less dimensional volume.
Also a composite material would be best used to construct the tank in order to reduce the weight burden, as less mass will require less energy to change it's position or velocity.

You can drive an air powered drilling machine for about 3/4 hr on a full 200kg bottle of nitrogen (@3000psi) providing 15 lbsft of torque.
This would require some reduction gearing to increase the torque to a useable value.
Might I suggest an epicyclic style of reduction as again, weight will be much reduced if compared with conventional parrallel shaft configurations

You should really consider a regeneration system in which motor would become a compressor when going down hill using a divertion manifold shuttle control to pump air back to the tank. Rather than you just exhausting all your energy store. (But do not try to market this in Holland.)

I have the drawings for an example I patented a few years back...
You can copy them if you like.

Please bear in mind that the equipment and material suggested can be prohibitively expensive though you could find some odds and ends by looking in the right places for scrap parts.
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W-ireless A-rtificial L-ifeform L-imited to O-bservation P-eacekeeping and E-fficient R-epair

[binge]

Well done on creating the worlds uglies car.

https://www.motordeaire.com/Img/Mini_Term.jpg

[Walloper]

[ZRX61]

[MaybeGuy]

i think itd be quite easy and definatly possible.

from what i can tell, this bike would go way more than 40mph because basically the faster the air comes out, the faster it goes.
the throttle could be the CO2 valve?

and yes, paint is awesome for designing bikes.

https://aycu03.webshots.com/image/16722/2005722431813449507_rs.jpg
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Blue_SV650S wrote: it was a sh1te wheelie, but it proves that he can get it up in 3rd and can do angles. In summery, mattsprattuk is a gobby little sh1tebag, dopehead tw4t, but sadly for all of us, he probably isn't THAT full of sh1te!!
Kickstart wrote: Hi I tend to agree with Matt. All the best Keith

[Walloper]