Hybrid motorcycle ideas

[drmouse]

Hi all

I have been thinking about his, on and off, for a couple of years. I would like to make the simplest possible hybrid conversion for a motorcycle. This has not been my number one priority up till now, but I may be changing jobs soon and my VW Bora 1.9TDi will no longer be the the most suitable choice of transport. I would be driving through rush-hour inner-city traffic, which will tank the efficiency of my VW. This has brought the motorcycle mods back to the fore.

There are a couple of ideas I have had for this. My first idea was simply to add a small series-wound motor with a sprocket at the back, driving the chain. This could be driven from batteries (a small pack, it's mainly for crawling through traffic), or from the generator on the bike if/when it was more efficient than the engine directly driving the wheel.

The other idea struck me when I was reading up on the charging system on my bike. It uses a permanent magnet, three phase generator to supply electric power from the engine. This, in essence, is what an AC or BLDC motor is. So why couldn't I just use a BLDC motor controller hooked up to the generator windings (obviously without the regulator/rectifier)? It has some significant disadvantages (like only being able to drive through the engine) and it will not be the most efficient motor on the planet (I think the winding resistance is very high compared to real motors, although I may be wrong), but it is already there.

So, what do you all think? I am no expert, but from my rough calcs either should work and be pretty cheap to implement (apart from the battery pack). I welcome any ideas or constructive criticism (or even an expert telling me I'm an idiot )

[redyaris]

drmouse
I to have a few half baked ideas as to how to make a hybrid motorcycle. What I had in mind would be to instal an electric hub motor; like the electric bicycles have, on the front wheel and then do the control system for drive and regenerative braking. A 125cc bike might be a good choice with streamlining or a 250cc bike with or without streamling.

[drmouse]

redyaris: I also considered these. I'm not convinced. For me, I can see problems with mechanical properties (will the bearings and others take the loads generated by a motorbike?) and also the power output (they all seem very low power).

For myself, I'm looking to convert my existing bike. This is a Kwak GPZ500s. It's a lovely bike, and has never returned less than 50mpg (imperial) even when thraping it (to my limits). Adding an electric drive for low speed operation on a secondary front sprocket seems the simplest way to go, and the cheapest. Driving the generator seems like it would be a much more compact solution.

The thing is, I don't want to take away from my main reason for having a motorbike (it's FUN!), and can't have a second bike just for commuting (no space, and my fiance would kill me).

[Frank Lee]

You are going to have to add a substantial amount of battery to get any useful range. That means lots of weight and volume or lots of money, take your pick. Either way, the baseline bike will not be as agile and sporty as it is now.

[drmouse]

I was not planning on getting much battery-only range out of it. The plan would be that it could be operated on batteries only for slow speed (heavy traffic) conditions, maybe up to 20mph, but only for short distances. A little balancing of when the motor should be used and when the engine, I believe it could save me some fuel.

Of course, this is still in the "I wonder" stages at the moment. If I am way off, I don't mind being told that.

[Johngee]

Hi, I read your posting about building a hybrid motorcycle. If you're still interested, please check our website on the build we did. It was a LOT of work, but hopefully we can help you avoid the pitfalls and get to the actual build a lot faster.
classic-hybrids.com

Sincerely, john

[sheepdog 44]

Could you elaborate a little on how it operates? I see you did a simple design of just mounting the electric motor and engine separately to the same chain. Is it just assist on the same throttle as gas? Or separate throttles?

[Frank Lee]

That setup is gonna be tough on the components, seeing as how all the stuff was put on the tension side of the chain.

[Johngee]

The pics that are in the reply are from my earliest try. And you are absolutely correct to state that the set-up is hard on components. In the beginning, I truly had NO CLUE as to what I was doing. But over time and lots of trial and error. I cam up with the bike in the Phase III. Take a look at phase III on classic-hybrid.com. Also look at the videos in the VIDEOS section. I am more than happy to share how it was done, as I think its a great project, and if I can help someone get there faster than I did, so much the better...

[Johngee]

The bike uses a custom designed throttle control which controls both the motor controller and a servo that opens and closes the carb. I tried various configurations and eventually found a large hubmotor from Enertrac in NY and then custom built the remainder as needed.