T
Tim McNamara
Guest
In article <[email protected]>,
Ben C <[email protected]> wrote:
> On 2007-10-20, Tim McNamara <[email protected]> wrote:
> > In article <[email protected]>,
> > [email protected] wrote:
> >
> >> I just found an interesting article from BERND Rohloff. He discuss
> >> the importance of the "IDEAL" gear for the engine (human leg). And
> >> the answer is:
> >>
> >> Small (15%) and constant gear steps over the appropiate overall
> >> gear ratio! YES!
> >
> > "YES?" Why "YES!" with such emphasis? Since this is Rohloff's
> > opinion that happens to support the hub he designed, it is not an
> > independent verification of anything.
> >
> > And he's also not necessarily right, either. The human body has a
> > much broader range of efficient functioning than is the case for
> > engines. Mistaking humans for "engines" causes all kinds of
> > conceptual problems and is a practice that should be stopped.
>
> My bike has 18 gears which are good for speeds in the range 0 to
> 30mph. My car has only five for 0 to 110mph.
>
> About 4 of the bike's gears overlap, so there are really 14 gears.
> This still means about one gear for every 2mph increment.
>
> Surely the car engine is much the more flexible?
Demonstrating that we're not engines. Trying to conceptualize ourselves
as engines leads to false conclusions about what makes for "efficient"
cycling.
I did a casual 56 mile ride yesterday on my 3 speed. My average speed
over that route was 16.2 mph, basically the same as my average speed at
the same perceived exertion over the same route on any of my derailleur
bikes. My cadence was quite a bit more variable because the steps
between the gears are quite a bit larger than is the case with my other
bikes. Clearly the 3 speed would be considered "less efficient" because
I could not keep my cadence within some "ideal" range (say, 80-120 RPM
has is often recommended in books), but it made not one whit of
difference in terms of performance nor in terms of enjoyment.
Ben C <[email protected]> wrote:
> On 2007-10-20, Tim McNamara <[email protected]> wrote:
> > In article <[email protected]>,
> > [email protected] wrote:
> >
> >> I just found an interesting article from BERND Rohloff. He discuss
> >> the importance of the "IDEAL" gear for the engine (human leg). And
> >> the answer is:
> >>
> >> Small (15%) and constant gear steps over the appropiate overall
> >> gear ratio! YES!
> >
> > "YES?" Why "YES!" with such emphasis? Since this is Rohloff's
> > opinion that happens to support the hub he designed, it is not an
> > independent verification of anything.
> >
> > And he's also not necessarily right, either. The human body has a
> > much broader range of efficient functioning than is the case for
> > engines. Mistaking humans for "engines" causes all kinds of
> > conceptual problems and is a practice that should be stopped.
>
> My bike has 18 gears which are good for speeds in the range 0 to
> 30mph. My car has only five for 0 to 110mph.
>
> About 4 of the bike's gears overlap, so there are really 14 gears.
> This still means about one gear for every 2mph increment.
>
> Surely the car engine is much the more flexible?
Demonstrating that we're not engines. Trying to conceptualize ourselves
as engines leads to false conclusions about what makes for "efficient"
cycling.
I did a casual 56 mile ride yesterday on my 3 speed. My average speed
over that route was 16.2 mph, basically the same as my average speed at
the same perceived exertion over the same route on any of my derailleur
bikes. My cadence was quite a bit more variable because the steps
between the gears are quite a bit larger than is the case with my other
bikes. Clearly the 3 speed would be considered "less efficient" because
I could not keep my cadence within some "ideal" range (say, 80-120 RPM
has is often recommended in books), but it made not one whit of
difference in terms of performance nor in terms of enjoyment.