Re: Electric Assist Tandem

On 5/2/2024 1:50 PM, Zen Cycle wrote:

On 5/2/2024 10:53 AM, Frank Krygowski wrote:

On 5/2/2024 9:00 AM, AMuzi wrote:

On 5/2/2024 4:33 AM, zen cycle wrote:

On 4/30/2024 8:56 PM, AMuzi wrote:

On 4/30/2024 7:21 PM, pH wrote:

I was driving along on my way home and noticed a a Jobst-yellow tandem of
some sort.
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I did a double take when I saw a Bosch-like motor bulb on the stoker's pedal
set!  I did not realize that there were electric assist tandems.
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By the time that realization set in it was too late to look and see if the
Captain's bottom bracket was motorized, too.
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I would not think that that would be the case, but you never know.
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pH in Aptos
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I think Yamaha and Shimno also make bottom bracket bulbs so no idea what it
was.
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I've seen several of the Ba-Feng (sp?) kit's of late as well.
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I'll try to do an un-scientific bike survey of what goes by sometime this
next month.
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pH in Aptos

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Yes battery assist tandems are a thing. As you note, several motor formats just as bicycles generally.
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https://2022.santana-tandem.com/en/tandem/e-tandem
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There's no point in more than one motor in a drive train. Or on both wheels for that matter.

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If we're talking about electric assist bicycles where it can still be propelled with legs in the event of a motor failure, yes. However some redundancy on vehicles without a 'back-up' is indeed practical.
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Turbine locomotives have motors on each drive wheel for exactly that purpose. If one motor fails, 7 more are generally enough to still do the job. If the turbine goes, they're still fucked though.

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Well, engineering is achieving a goal with efficiency of limited resources; in the case of a tandem, weight, cost, complexity and service over the system life.  There's room for interpretation and weighing of those factors but a single drive unit has been the overwhelming format.
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Conversely, for an airliner I agree that multiple engines is a reasonable solution.

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Right. Benefits vs. detriments.
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Detriment of a single motor failure on a tandem: Riders have to pedal a bit harder. Versus detriment of engine failure on a single engine airliner: 100+ fatalities, years or decades of litigation and penalties, loss of future customers, etc.
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 Boeing seems to have come to a slightly different conclusion.

?? Not about multiple engine airliners. Boeing hasn't made a single-engine commercial aircraft in my lifetime.
--
Andrew Muzi
am@yellowjersey.org
Open every day since 1 April, 1971