The Dream Bike Build (w/video)



The first donor bike: 1985 Honda VF500F

I’ve been riding motorcycles for over 45 years.  I’ve built several gas-powered bikes, and once I got it into my head what the electric drivetrain could deliver, all that focus fell directly on building electric motorcycles.  After decades of riding motorcycles and owning more bikes than I’d care to admit to, riding a big electric motor-powered motorcycle showed me a brand-new experience.  At first, most people who start heading down this road of obsession pick up some random chassis on Craigslist for short money and end up with, at the very least, an introduction to what the electric ride is all about.  This is how I started – with a 1985 Honda VF500F with a blown motor.

Being not so much a fan of mid ’80s bikes, and a huge fan of 1970s-vintage road-racers (please don’t say the word “café” around me), when I found a 1971 Yamaha R5 frame in a chicken-coop in Brookfield MA, (the very same frame that took Yamaha through the late ’80s writing roadracing history) I took the entire drivetrain out of the Honda and build the “R5e“, a tribute to everything we worked on in the ’80s, updated for the 21st century.  Here, for a taste of that, is a video tribute to my misspent youth and “the loop”, in Harvard, MA:

1975 race-ready Yamaha RD350B

Let’s just say the last time a motorcycle scared the crap out of me was riding this bike’s gas counterpart in 1987 – a bored, ported, blueprinted race-ready Yamaha RD350.  But my electric R5e was faster.

The R5e, like most projects, was pretty much obsolete as soon as I completed it.  I knew exactly what I wanted to change, got some good basic experience behind me building with a fairly standard drivetrain – a PMDC motor, some conservative batteries and components that were originally offered as golf-cart controls.  Those lessons (and parts) behind me, as well as several opportunities to ride some remarkable production-ready bikes, and I started formulating a plan for my dream bike.  A 100kw-powered, top-of-the-charts-handling sport bike that can stand toe-to-toe with any 600cc gas bike on the road or track.

600RR frame

CBR600RR frame

The first thing to decide on was the chassis, and at the risk of sparking some passionate debate on the current state of the motorcycle art, I narrowed it down to two bikes – the Yamaha R6, and the Honda CBR600RR.  They both have a huge central cavity in their frame for batteries, and will match any bike on the road for handling out of the box.

The batteries?  We need something that has the absolute maximum for energy and power density, what with cost being no obstacle.  (We’re dreaming, right?)  Though the Tesla’s Panasonic cells boast some huge numbers, they may not be the best choice for a bike because of their volume and their power delivery.  The hot setup, based on what everybody is using in their production builds?  Probably Farasis Energy cells.   Here’s a look at the 25ah prismatic cells’ their data sheet (pdf), if you’re into geeking out on batteries.  Both Brammo and Zero are now using Farasis packs.

Now, the motor.  I think the clear choice is the Emrax, based on my comparisons here, on the Electric Chronicles.  Everything I’ve seen that can match my performance targets is rated around 100kw, and the Emrax is an astoundingly light 27lbs, compared to at least 50-75lbs for the next best option.  Everything on a motorcycle is about power-to-weight.  It’s a challenge, though.  It’s an “outrunner” motor – the outside case spins rather than the more conventional design where an output shaft is delivering the power.  This is a common design for what the motor was intended – light aircraft, where the prop mounts on the case of the motor.  So, it’s a little more work to mount on a motorcycle frame.

It’s a liquid-cooled, AC motor, and here’s what it looks like:

Emrax 268

Emrax 268

mmmm. Beefy.

We have to drive that motor, and for that job we’re going to look at the Mission controller, here: Mission Motor Control Inverter.  You’ve got to be able to match up the motor with the controller, and you can easily under-drive a motor like this with a lesser package.  This will ensure we’re going to get all of the 100kw out of this motor, and maybe a bit more.  And thanks to a certain Ohio State student for that tip.

The final result?  We’re looking at a 450-500lb bike with around 100-mile range that will do 0-60 in close to 2 seconds.  The top speed would be near 150mph.  This bike will match almost any bike out there for handling.  It will meet, or maybe exceed several already legendary bikes – the Mission R/RS, the MotoCzysz E1pc, the Lightning 218, the Energica Ego, and is in a completely different class than the Brammo Empulse and the Zero SR, both respectable sport bikes.

So yes.  This bike would be completely insane.  And by that I mean “just right”.

It’s going to be a long, cold (but dream-filled) winter…

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7 Comments on "The Dream Bike Build (w/video)"

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Ahh, the Yamaha RD350… That brings back memories. Made you feel like you wanted to fly. So I sold it for a hang glider.. Well back then, it was more of a kite, 1979 Wills Wing Raven. Enjoyed the heck out of the video Ted.

My brother had an H2 and an H3 Kawasaki triple 2 stroke with expansion chambers.

Wheelies up and down the neighbor hood.

Sweet. Dream bike indeed.
Back on Earth, about 200 of the Farasis packs you pointed to would be needed to reach 100 kW peak; 100 kg (without enclosure), 18 kW*h total.
I don’t know how you’re going to do it, I can only hope you’ll find room for all this…

Interesting he’s using an out runner motor like on RC airplanes.

Is he running a 1 speed gear box? (or did I miss it)

So is io saying that these Farassis batteries only have a 5.6 C rate? That doesn’t seem very high.

I don’t think Brammo is using Farasis cells in their production bikes – they’re still using 10 Ah cells from an unnamed Chinese supplier IIRC.

Farasis rates their cells at 7C for 10s. At 50% SOC, the cells will sag down to about 3.4V, which is around 600 watts per cell. 170 cells should be sufficient to supply 100 kW.

I think Zero’s 2015 bikes are using a slightly denser cell, probably still from Faraasis, to get the extra capacity.

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