Hi all,
I'm looking into building my very first motorized bike, but before I commit to simply slapping a gas engine - kit or otherwise - onto a bicycle I've decided to consider alternate systems. I figure that since I'm going to be putting some DIY effort into this thing I might as well make it interesting so long as performance isn't going to suffer too badly. Obviously I'm not quite at the design stage and am just looking to brainstorm. Basically I'd like to know what my options are within my technical requirements.
First off, I'd like the bike to go a minimum of 30mph. The faster the maximum speed the better up to the point where it causes control issues, but the bike can't be a wimp. I don't mind if it has to warm up before optimal efficiency, but it should be able to reach 30mph within 15 minutes of starting. I am not averse to having to prime a system before or during riding, or changing fuel supplies on-the-fly if the system is designed for it, but weight is a consideration as the bike needs to remain light enough to be a pedaled for practical distances in the event that I run out of fuel. When it comes to range, I'd like to carry no more than 10 pounds of fuel and be able to travel 50 miles with it.
Let's get creative! Something tells me that precious little other than gasoline is going to meet these requirements, but if nothing else some of these ideas may make for good discussion among the chemistry and engineering inclined.
One of my first ideas was to harness a vinegar-baking soda reaction because basically I can get them both for free. The reaction produces CO2 and water, meaning there's a great deal of expansive force much in the same fashion as steam and can thus be used to drive a piston. I'm not aware of the full scope of technical abilities/limitations this system possesses or if it matches up to what I need... there aren't many google results for "vinegar powered engine". I realize I'd have to custom-build something but would like to get some kind of idea what to expect for performance first. I also began to examine steam engine bicycles and saw some interesting stuff, but I don't know if it can be modified to fit my needs. Obviously there are numerous ways to create heat through not only combustion but also chemical reaction.
Sugar is another possible high-energy fuel source I have access to for cheap - the question is how to extract energy from it in a fashion practical for my needs... might I be able to refine usable amounts of alcohol? Hydrogen would be a great fuel but has key drawbacks such as embrittlement of engine parts, storage difficulty, and extreme volatility; a relatively safer thing to work with is methane. On the plus side it can be extracted via the composting process, but on the downside it's not the easiest to get fuel other than what you bring with you.
There are some interesting diesel engines out there, and I like the idea of being able to use vegetable oil for fuel in a pinch, but at small sizes they tend to have considerably short lifespans in relation to price. Unless I'm missing something there's really little reason to choose diesel over gasoline considering the size of the application.
The last of my ideas is a "bow drive" which would operate by storing kinetic energy in a flexible rod and in turn using that to produce rotational force, possibly via a flywheel. There are a whoooole bunch of drawbacks and benefits to this idea, but for the most part I don't believe it capable of practically achieving what I'd like it to.
Anyway, that's all I've got. I'd love to hear some thoughts!
I'm looking into building my very first motorized bike, but before I commit to simply slapping a gas engine - kit or otherwise - onto a bicycle I've decided to consider alternate systems. I figure that since I'm going to be putting some DIY effort into this thing I might as well make it interesting so long as performance isn't going to suffer too badly. Obviously I'm not quite at the design stage and am just looking to brainstorm. Basically I'd like to know what my options are within my technical requirements.
First off, I'd like the bike to go a minimum of 30mph. The faster the maximum speed the better up to the point where it causes control issues, but the bike can't be a wimp. I don't mind if it has to warm up before optimal efficiency, but it should be able to reach 30mph within 15 minutes of starting. I am not averse to having to prime a system before or during riding, or changing fuel supplies on-the-fly if the system is designed for it, but weight is a consideration as the bike needs to remain light enough to be a pedaled for practical distances in the event that I run out of fuel. When it comes to range, I'd like to carry no more than 10 pounds of fuel and be able to travel 50 miles with it.
Let's get creative! Something tells me that precious little other than gasoline is going to meet these requirements, but if nothing else some of these ideas may make for good discussion among the chemistry and engineering inclined.
One of my first ideas was to harness a vinegar-baking soda reaction because basically I can get them both for free. The reaction produces CO2 and water, meaning there's a great deal of expansive force much in the same fashion as steam and can thus be used to drive a piston. I'm not aware of the full scope of technical abilities/limitations this system possesses or if it matches up to what I need... there aren't many google results for "vinegar powered engine". I realize I'd have to custom-build something but would like to get some kind of idea what to expect for performance first. I also began to examine steam engine bicycles and saw some interesting stuff, but I don't know if it can be modified to fit my needs. Obviously there are numerous ways to create heat through not only combustion but also chemical reaction.
Sugar is another possible high-energy fuel source I have access to for cheap - the question is how to extract energy from it in a fashion practical for my needs... might I be able to refine usable amounts of alcohol? Hydrogen would be a great fuel but has key drawbacks such as embrittlement of engine parts, storage difficulty, and extreme volatility; a relatively safer thing to work with is methane. On the plus side it can be extracted via the composting process, but on the downside it's not the easiest to get fuel other than what you bring with you.
There are some interesting diesel engines out there, and I like the idea of being able to use vegetable oil for fuel in a pinch, but at small sizes they tend to have considerably short lifespans in relation to price. Unless I'm missing something there's really little reason to choose diesel over gasoline considering the size of the application.
The last of my ideas is a "bow drive" which would operate by storing kinetic energy in a flexible rod and in turn using that to produce rotational force, possibly via a flywheel. There are a whoooole bunch of drawbacks and benefits to this idea, but for the most part I don't believe it capable of practically achieving what I'd like it to.
Anyway, that's all I've got. I'd love to hear some thoughts!
I realized going in that the scope of my ambition was likely beyond realistic practicality, but without running ideas by others there's no way to know what's absurd or not.
