Re: Electric Assist Tandem

On 5/2/2024 2:15 PM, Zen Cycle wrote:

On 5/2/2024 3:10 PM, AMuzi wrote:

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.

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?? Not about multiple engine airliners. Boeing hasn't made a single-engine commercial aircraft in my lifetime.

 Yes, Andrew, not wrt multiple engines.
 

There's a difference between the design and printed (I suppose now digitized) plans and actual QC at the loading dock or, for Boeing, runway.
Much of the bad press (and they do have QC production failings) is related to airline maintenance and not Boeing's actual product as delivered. Recent examples include wheel fall off, emergency slide fall off, improperly secured engine cowl fall apart, etc.
I'm thinking here of a lawsuit Ford settled in which the 2d owner of a Ford van had recently installed mismatched used tires and suffered a fatal crash from tire failure. Sympathetic plaintiff notwithstanding, that had nothing to do with Ford...
--
Andrew Muzi
am@yellowjersey.org
Open every day since 1 April, 1971