Re: Electric Assist Tandem

On 5/2/2024 9:53 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.
>
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.
>
By the time that realization set in it was too late to
look and see if the
Captain's bottom bracket was motorized, too.
>
I would not think that that would be the case, but you
never know.
>
pH in Aptos
>
I think Yamaha and Shimno also make bottom bracket
bulbs so no idea what it
was.
>
I've seen several of the Ba-Feng (sp?) kit's of late as
well.
>
I'll try to do an un-scientific bike survey of what
goes by sometime this
next month.
>
pH in Aptos

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

>
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.
>
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.

>
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.
>
Conversely, for an airliner I agree that multiple engines
is a reasonable solution.

 
Right. Benefits vs. detriments.
 
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.
 

+1
>
That said, benefits vs costs is inherently subjective.
>
For every guy who says an extra six kilos is a ridiculous
burden there's some other guy who says greater dependability
for only six kilos more is worthwhile.