Am Thu, 18 Apr 2024 21:04:42 GMT schrieb Roger Merriman
<
roger@sarlet.com>:
Wolfgang Strobl <news5@mystrobl.de> wrote:
...
But thats beside the point. The point being, giving a weak person the
peak power and the endurace of a world class athlete is just a fancy way
of describing the substitution of muscle power by motor power.
Your wrong about the fact, too, and I've already mentioned that in
earlier discussions. You ignore that humans have a power curve much
different from a motor, even when accounting for that bicycle simulation
done by its controller. And you convently ignore that most humans
aren't professional competetive cyclists.
No I didn’t professional cyclists produce way more power both peak and
continuous,
So you are doing it again: you conveniently ignore that most humans
aren't top level professional competive cyclists, by talking about what
professional cyclists do and by ignoring what ordinary people can do and
what these people do with e-bikes on the one hand, and with real
bicycles, on the other hand. But let's talk about that distraction, for
a moment and lets mention in passing that some competetive professional
offroad motorcyclists need more strength and endurance than your average
cyclist on his bike.
<
https://theselvedgeyard.files.wordpress.com/2012/09/steve-mcqueen-husqvarna-011.jpg>
some beyond 2000 watts some just under, which is comfortably
above what a E bike can produce.
So now you are not only equating your average cyclist to word class
athletes, you are now cherry picking the best of the best in that group?
"`Curiouser and curiouser!' cried Alice."
But perhaps you are just confused about what a human power curve tells
about how much power ordinary people can deliver over what time span.
In reality, a TdF athlete only spends about 140 W while riding in the
peleton. Event the leader at the front rarely exceeds 245 W there.
Source:
<
https://www.tour-magazin.de/profi-radsport/tour-de-france/tour-de-france-verstehen-wattleistungen-im-check-welche-leistung-bringen-die-profis-aufs-pedal/>
| During a normal stage of the Tour de France, pro riders can
| pump out around 230-250 watts on average, which equates to
| burning about 900 calories per hour. But on some of the
| harder stages they can average over 300 watts, or 1,100
| calories per hour. Tadej Pogacar has a Functional Threshold
| Power – an estimate of the power he can sustain for around
| one hour – of around 415 watts. But for explosive one-hour
| attacks on big climbs, some Tour riders have been known to
| exceed an average of 500 watts. And in the final stages of a
| sprint finish, sprinters can hit maximal efforts of over
| 1,500 watts.
from
<
https://www.alpecincycling.com/en/pro-peloton/from-body-fat-to-power-output-anatomy-of-a-tour-de-france-rider/>
Sprinters sometimes accelerate to 65-70 km/h - once, in the final
sprint, after they had saved their strength for most of the time with
the support of helpers. 600 W in addition to your own 136 W (plus 340
percent, remember?) is more than enough to accelerate an e-bike in no
time to 25 km/h.
My back-of-the-envelope calculation using 136 W and +600W shows an about
fivefold power advantage for the e-bike. Not much, you think, cars come
with 50 to 250 hp, making not that much difference on the road? Think
again.
When I look at my power curve over the the past 12 months, that roughly
amounts to sustained power over five seconds vs. sustained power over
one hour, a factor of 720!
A 70 kg cyclist on a 10 kg bicycle needs about 14 seconds in order to
accelerate to 25 km/h. Adding a generous 10 kg for motor and batteries
reduces that to less than three seconds, the actual quotient is <21%.
percent.
To conclude this observation, which distracts from the actual point,
even old and weak, but healthy cyclists are able to produce 140 W or,
say, 2.2 W/kg for less than a half a minute, but people rarely do more,
when it isn't necessary.
You don't need 250 W, even for riding a heavy dutch type bicycle, 140 W
is enough for doing 22 km/h.
But what do I notice when looking at how average people actually use
their e-bikes on flat ground? Those people ride their e-bikes with about
22 km/h, too!
Adding another 500 $ or € to the cost of a better e-bike (say, 2500 €)
is al lot more attractive than adding the same amount to a 500 €
bicycle. Now that many modern e-bikes have got more power, lighter
frames and better gears, people _still_ ride their e-bikes with about
22-23 km/h, just to not trigger the speed limiter.
Unlike cyclists, e-bikers are not motivated or forced to adapt their
speed to circumstances such as wind, incline or ground conditions. Why
should you pedal more than 70 watts at a 4% hill, going 22 km/h? Easily
done on a 25 km/h e-bike restricted to 250 W on paper. How many
ordinary people (not doing cycling as a sport) do you know who can
sustain > 304 W for hours?
Doing the same calculation on the lower end (flat ground) or the upper
end (say, 20% grades) gives similar results, less than <40 W on flat
ground, even 12 % with 22 km/h is doable, needing 175 W human power plus
600 W from the motor.
Are you able to ride longer 12 % grade uphill with a speed of 22 km/h? I
guess not.
Of course, your average utility or leisure cyclist couldn't and wouldn't
do that, either, not even when switching to an e-bike. He or she would
do what I'd do (and actually tried as an experiment, as you perhaps
remember from my previous answer to your question), I'd reduce the
120-130 W I'd need for riding 4-5 km/h uphill to those 90 W I can
sustain for hours, let the motor add 340% ~ 306 W, doing an easily
ridden 12 km/h there.
But that's me. From looking at what people do who _are_ into ebikes I
conclude that people are even more lazy, when given the choice they paid
real money for. They reduce their speed to what they can do without
having to learn to ride really slow, they slow down to about 8 km/h, now
needing about 230 W only for those 12 %, spending 50-60 W human power
plus 170-180 W from the motor.
Just what they spend when going for a walk, even under extreme
circumstances.
Usually, e-bikes do what people usually do with motor vehicles, their
cruising speed is limited mostly by regulations, not by the limits of
their own endurance, muscle strength or cardio fitness. Motorists use
all the power their motor and external energy source delivers, within
the regulatory limits.
Cylists, are lazy too, even more so, because they have to. Ten colories
spent on needlessly accelerating and then braking are ten calories lost
and not available when the gained speed could have been used for just
rooling with speed for a while.
Riding at your limit without overdoing is, getting strength and
endurance is an art. But even without all that sport science training
methods, just _using_ your own power when all you have is that power,
for getting around on a bicycle far and fast enough will get you more
strength and endurance, on the long run. This makes cycling more
usefull and more enjoyable, at the same time.
Adding a strong motor to a bicycle, as it is done with e-bikes limited
to 25 km/h, eliminates most of that. Arguing "but this still is
cycling!!" is like selling electric wheelchairs to healthy people and
pointing to the Paralympics to justify it.
-- Thank you for observing all safety precautions
…