Question About Aero Bike Idea - Mike Flanagan UK

[Flantoons]

Please, may I ask for a comment on my idea for the Aero Bike?
I want to store energy in the frame of the bike, by pumping with your arms on the

handlebars to create air pressure, (at the same time as you do your normal

pedaling). Also perhaps regenerative braking can store energy too.

My drawing here explains the idea.
flantoons.co.uk/aero-%20bike.jpg

Many thanks,
Mike Flanagan UK

 

[Unrest]

Can you actually ride that? If you're leaning forward with weight on the handlebars, how do you pull them up? Even then it would be horrible hard work, and bad for your back. Same with the cylinder on the front fork. That's why some mountain bikes can have the shock absorbers locked up, so you aren't wasting energy doing all that pumping.

I like the idea of utilizing that empty space inside the frame. But I doubt you could store any useful amount of energy like that. If you put any significant pressure in it, the frame would have to be made stronger to take the ordinary bike loads added to the pressure load, and with enough safety factor to prevent it exploding or becoming like a rocket when it cracks.

Compressed air is basically useless for propulsion of normal vehicles because it has a very low power to weight ratio. You need a lot of heavy pressure vessel to hold much energy.

 

[xxChrisxx]

Goes against all convention of bike design. You don't what bits to move that don't have to as that wastes energy from going forward. Let's take a look at the energy path for a rigid bike, we know the more steps we add the less efficient a system is.

With a rigid bike.
You -> Pedals -> Motion.

With your system
You -> Compressed air -> Pedals -> Motion.

The vast majority of the time you are temporarily storing energy only to be used a split second later. It would be far less tiring to just pedal a rigid bike. As you are the only input, your system will be far more tiring and awkward to ride.

As unrest said, you aren't going to store that much energy even if you can store it at all. Especially the way yuo've drawn it. Either you are comrpessing air with the pedals also (doing work against yourself), or you are just venting the pressurised air into the atmosphere as you have no mechanism to stop the air from rushing out the piston chamber.

Then you need to ask the question, if you sort out a mechanism to store the pressure and realease it on que. Is it really worth the extra weight and complexity?

 

[RandomGuy88]

I think it might also be difficult to release the energy at the proper time. In your drawing, if the compressed air is pushing the piston towards your pedals than it would assist in your pedaling motion. However, if the the gear were rotated 180 degrees and the compressed air were pushing the piston towards the pedals then you would actually be opposing your pedal motion. So you would have to make sure that the power stroke is in phase with your pedaling.