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:
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.