Philosophy time.
A bit about me first. As my name suggests I've got an interest in diving. Significantly I've got an interest in mixed gas diving. I took up this sport at a time when there was no training available for surface oriented mixed gas diving at all. There were no readily available decompression tables. I taught myself, which was hard as most of the available information was either classified or proprietary. Still I managed to do it and survive, even writing my own decompression tables for gas mixes that no-one else was using. Lots of people didn't survive. I heard a little later that the death rate for mixed gas diving was running at about 20% per dive. I think that was an over estimate, but it was pretty high.
Then I started to get interested in closed circuit mixed gas diving. There was only one “availableâ€
rebreather at the time. They were five years wages each, minimum order of five and only available to reputable governments. And I'm not kidding about the “reputable governments†bit. It was classified as a weapon just like the guided missiles made by the same company and every bit as hard to obtain.
So I made my own. Not only did I make my own, I was a joint founder of AARG which was a group of like minded individuals who were interested in building their own rebreathers. “So I made my own†encapsulates a 5 year journey that took me to some interesting places (including working for an underwater electric vehicle factory), cost me at least tens of thousands of dollars and at least 8000 hours of my time. Perhaps the amount of research I did was overkill but unlike an electric motorcycle, that simply stops, if a rebreather goes wrong the least dangerous thing that will happen is you will inhale a saturated solution of calcium hydroxide (like the drain cleaner, DrainO). More usually you will go to sleep and drown, or convulse and drown or surface and die of the bends.
I think my home build credentials are impeccable. I've done it, I've supported it, I've helped others do it.
So when would I build a rebreather and when would I buy one? In the days when there were none available, the choice was easy. You build or go without. Now 20 years later there are factory built ones around (most are copies of the AARG machines). Now I'd only build if I was going to build something that did things that the factory machines can't do. Cost is part of the reason. It's a lot cheaper to buy the factory kit. They buy their parts in bulk and there's little wastage. For me if I need a tube that's 300 mm long I have to buy a 6 metre pipe to get it. I spend a day of my time researching where I can buy said pipe and I have to drive to the pipe merchants and buy just one at full retail. The factory spends a day researching, gets a pallet of 50 delivered at wholesale price and makes 1000 tubes. For each rebreather part they spend a few seconds and a small part of a dollar where I spend a day and 50 dollars. If I need to put a tapered thread on the inside and outside of a fitting, I buy a tap and die. They're 600 dollars each and I use them both twice. The so each fitting costs me 300 dollars. Compare that with the factory who also spends 600 dollars each but uses them 2000 times. So each fitting costs them 30 cents. Multiply that out for the hundreds of parts involved, include all the parts that you've bought and then discovered they weren't quite right and all the special tools required and you soon discover that building yourself is the most expensive and time consuming way to do it. I see the lessons learnt from building rebreathers as directly applicable to electric bikes.
Safety is the other reason. It's not as much of a concern on an electric bike. They're far less likely to kill you than rebreathers. But it's still a concern. Yes they're slower than the ICE bikes they're based on, but there are a lot of hacks that you're going to be the one out there testing. I'd rather have the factory test riders take that risk for me. Again that's a value judgement. I've taken plenty of risks in the past but only after I'd thought them through and determined that there was no way to do what I wanted without taking those risks.
Remember that blog I linked to? I really strongly identified with that guy. He immersed himself in the electric bike world in order to complete his project. I did the same in the rebreather world (such as it was then). He built a lot and then discarded what he'd built as he learnt more. I had the same experience. He made a lot of friends along the way. So did I. In the end he died while testing. I didn't but I sure came close.
So right now if you apply the criterion that I use for rebreathers, “only build if I was going to build something that did things that the factory machines can't do†that leaves you with a lot of scope. There are only really 3 bikes on the market at the moment. The Zero dirtbike, the Zero street bike and the Brammo street bike (all three have two different versions, but they're really the same bikes). There are others coming like the Brammo 10.0 but if there's one thing I've really learnt from 'breathers it's that it's much easier to write a spec sheet than it is to deliver a product. So the list of things that current electrics can't do or can't be is long. No two seat bikes yet. No bikes with a freeway range beyond about 20 km. No bikes with a top speed over 110 km/h. No choppers, no trials bikes, no drag bikes, no faired bikes. If you're wanting to home build a bike that is or does any of those things, then hats off to you! Go forth and produce something amazing. Tell the rest of us how you did it (like I did with rebreathers). Home building now should be the realm of the incredible one off work of art.
If you say you want to do the equivalent of building a rebreather that is more dangerous and has less range than a factory machine then I will continue to suggest that you just buy a factory one. I'll even do it on a home brew sub section of an electric vehicle forum.
=:)
