The Electric Garage: The Corbin “Quicksilver”

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In 1974 Mike Corbin set the Electric Motorcycle Land Speed Record at Bonneville with “Quicksilver”- a bike that, in 1972 set the previous Land Speed Record running lead/acid batteries.  The 1974 record of 165.397MPH  stood for over 30 years. There aren’t many photos, but here’s what I’ve got:

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The bike was running silver-zinc batteries (thus the name).  Now, you may have never heard of silver-zinc chemistry, or you may think it’s a long-lost ancestor of the current lithium battery we all run today.  Well, you’d be wrong.  Silver-zinc is a well known chemistry, it’s still in use, and to find the poster child for sliver-zinc chemistry you’d have to go to outer space.  Mars, to be precise.  Yeah, we’re talking the batteries in the Mars “Curiosity” Rover, and yes, Yardney is still around.

Take a look at their website, here.  Yardney is into lithium chemistry too, but look at these numbers for silver-zinc, here, on their datasheet.  Here’s what jumps out:  Wh/lb ratings of anywhere from 43 to 69.  For reference, an average LiFePO4 prismatic cell is around 30-35 Wh/lb.  Back in ’74, they represented a 8x “more available power” advantage over lead.

Here are the specs I could get:

  • Silver Zinc Batts by Yardney
  • System Voltage: 120 v , 1200 amps
  • Charged with industrial off board charger
  • Motors, starter motors from A-4 fighter plane, bought military surplus.  Intermittent duty, Series wound DC , silver conductors
  • LOA: 9’6″
  • Weight: 772lbs (935 lbs with rider)

Oh, the controller?  How about this:

  • Three stage magnetic contractors , with a spring loaded giant knife switch for shut off.   A 250A fuse in parallel bought time for knife to clear without arc.  The magnetics could not survive the opening arc.

To which I responded, “holy shit”.  To which Mike responded, “That’s what I said…”

The bike was the first electric vehicle raced with battery technology beyond simple lead/acid.

For a pretty complete picture of what Corbin was doing in the mid-seventies, see my post here.  It talks a bit about the batteries there too.  I also did a post on the Corbin motorcycles here, after seeing one of the bikes at the Springfield Museums. A pretty complete history of Mike and his work with electric vehicles, starting with an electric minibike can be found here- Keep Your Eye on the Sparrow.

You can see the bike, today, in person, at the Small Wonders Microcar Museum, in in Crystal Lake, IL.

…and yeah.  I’m a bit of a Corbin groupie.

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3 responses to “The Electric Garage: The Corbin “Quicksilver”

  1. Corbin probably wasn’t using the low rate (LR) cells, they can’t provide the power a LSR bike would need.

    At the maximum continuous rate of 2.5C the low rate cells provide substantially less energy (LR30).
    32.7 Wh/lb = 71.9 Wh/kg and 87.5 W/lb = 192 W/kg

    Something like an 80s2p pack of HR90 cells would provide 120V and 1200 amps (@ 6.7C continuous, sag down to 106V), 520 pound total cell weight.
    HR90 is 32.7 Wh/lb = 72 Wh/kg and 246 W/lb = 540 W/kg

    Compare to modern lithium NMC (EIG C020) @ 5C continuous:
    151 Wh/kg and 794 W/kg, 10s burst 2300 W/kg

    If those specs were available 40 years ago, then they’re waaaay better than lead acid.

  2. Pingback: Almost 40 Years Ago, Quicksilver Set Electric Motorcycle Land Speed Record at 165.397 mph·

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