Am Wed, 01 Nov 2023 13:01:25 GMT schrieb Roger Merriman
You didn't answer this question, which leads me to believe you wouldn't.
You probably would consider a mere 20 Watts provided by a motor to be an
unfair advantage, and rightly so.
>>
>> You casually dismiss "peak power ... still sub 1k" as irrelevant. How
>> long can you sustain 1kW, you say?
>
>No idea I’m aware that fit folks can hit over 1k in a sprint
Even I old geezer was able to do over 1 k on the bike a while ago - for
about one second.
Perhaps you believe humans to have a power curve almost as flat as an
internal combustion engine, or as flat as an electric motor. A older VW
Id.3 has a continuous power of 70 kW and a peak power of 110 kW. That's
less than 60% more peak power than continuous power output.
Source: <
https://de.wikipedia.org/wiki/VW_ID.3>.
Cyclists using a power meter on their bicycles have known for years that
a power curve like that would be pure fiction. Garmin and others sell
many gadgets able to collect power while riding and offer software for
analyzing the collected data. I'm using an Garmin Edge 1030 combined
with a pair of Garmin XC200 on my most recent road bike, my wife has got
a Garmin watch and a SRAM powermeter crank on her new bike.
<
https://www.sram.com/en/sram/models/pm-riv-1w-d1>
While the mechanics of how muscles work has been extensively studied by
sport scientists in the past, it seems to me that these widely available
tools have only recently found their way into the scientific literature.
Anyway, I just found this:
<
https://link.springer.com/article/10.1007/s00421-021-04833-y/figures/2>
"An illustration of the spectrum of physiological responses across the
power-duration relationship using arbitrary power output values"
from <
https://link.springer.com/article/10.1007/s00421-021-04833-y>
Unfortunately, that illustration doesn't tell from what data that
concrete curve actually has been derived. But the shape of this curve
fits very well with the individual curves that I can look at for my
individual rides or as an average over many rides.
>some 2k but
>these are still human sized levels of power, note that’s peak the e bike
>will not produce that nominally where again it’s more human level of power
>very good human level admittedly but even so.
Or so you believe if you haven't ever seen a human power curve.
But to equate the short-term performance of a competitive athlete over a
few seconds with the performance that an ordinary cyclist can achieve
over the long term is bordering on fraud, if you know better.
But that's exactly what is done when selling e-bikes as some kind of
bicycle to the audience.
An e-bike that is legally classified as a bicycle in Germany and other
European countries is limited to 25 km/h and is allowed to add an
average power of 250 W in a sliding time window of 30 minutes. This
means that any amount of power may be added within these thirty minutes
as long as this average value is not exceeded and the engine does not
overheat during a test. Bosch aggressively advertises "up to 600W" and
340% for some motors, but could equally sell "up to 1 kW and 400%", or
even more, without breaking the law. Given that people rarely need that
much power for more than half an hour when restricted to 25 km/h, this
essentially boils down to "no real restriction whatsoever".
Have a look at
<
https://www.mystrobl.de/ws/pic/fahrrad/power/powercurve.jpg>
That's a snapshot of a graph power vs time about how long I was able to
hold a certain amount of power, over a logarithmic scale for time,
starting with one second on the left and five hours on the right. It is
quite similar to the curve shown in the article linked above.
As you will notice, I was able to output between 0.750 kW and 1 kW at
max, for one second, but less than 100 W over five hours. That's an
order of magnitude less, factor 10, not a factor of 1.6.
Let's calculate. When I generously take 1.6 times my 100 W continuous
power from my best >5h ride, I'm at 160 W. That I can hold for about two
minutes, according to the graph.
2 minutes vs two hours, that's a factor of 150.
But wait, there is more.
On my last >5h ride I was able to generate an average of 72 watts and
only did an average of 17 km/h, in hilly terrain, average grade 1%.
Adding 340% motor power is both within what German law allows and what a
Pedelec motor from Bosch actually delivers
<
https://www.bosch-ebike.com/en/products/performance-line-cx/>
So adding 250 W on average to my lowly 72 W for as long as I like is
both legal and practical.
What could I do with that 322 W combined? Assuming a road bike or an
E-MTB with smooth tires, I'd easily do that trip with an average speed
of 33-36 km/h, mostly depending on actual aerodynamics. Most probably I
wouldn't, for obvious reasons: there is no motor power at >25 km/h.
Or would I? Actually we've calculated with averages. In actual fact, I
can do much more than 72 W, see the power curve above, but only for
short times. I'm riding in hilly terrain, sometimes going up and down
with a grade of 3, 6, 10 or sometimes even 12 percent. I could do up to
4 % uphill with slightly less than 25 km/h, continuously, without
spending more than 72 W of my own power, or do 10 % with about 15 km/h.
And then, crouching behind the handlebars, rolling down those four
percent gradients at 44 km/h without pedaling at all - reducing my self
generated average power to even less than 72 Watt.
Seriously: if you know how difficult it is to increase your average
performance by even a few percent, or at least to maintain it at this
level as you get older, then that gross statement regarding "human
level" comes is pretty crazy.
>>
>>
>>>
>>> In essence EMTB still ride like bikes not motorcycles,
>>
>> Most smaller off-road motorcycles basically ride like MTB. I'm not
>> talking about off-road sports, but rather the use of bikes as a means of
>> transportation, whether on the way to work, for business, or for
>> leisure. There, even a small amount (much less that what's nowerdays
>> state of the "art" wrt e-bikes) makes a difference like between day and
>> night.
>>
>They really don’t even a EMTb extra 10kg or less is noticeable, small
>motorbikes even mopeds are a lot more and this radically changes how they
>ride and also where.
I spent half a day riding an lented older E-MTB up and down a nearby
hill (8 % up to 11 %) in France, this spring, after mounting my own
power meter pedals. Modern E-Bike motors offer even more power, so I
assume my conclusion applies even more to these.
|Extended Boost is a new and innovative function in eMTB
|mode. The unique dynamism means that obstacles can be
|overcome with ease by applying the right amount of pressure
|to the pedal. The pedals rarely, if ever, jam. If the front
|wheel is already on the step, a slight pedal pressure is all
|it takes to give the decisive "kick". This takes pedal
|management to a whole new level.
Quoted from the Bosch article.
None of my bicycles can do anything remotely similar to that.
Even that according to current standard somewhat inferior E-Bike (no
Extended Boost, for example) radically changes how one rides and where.
This cuts both ways, by the way: It makes riding up an 11% grade easier
as riding up a hill less than half as steep and it needs completely
different motorics. You learn how to operate a motor much stronger and
having more endurance than yourself using your feed as a kind of
accelerator pedal, but you unlearn how to do it with your own power. The
starting aid makes it unnecessary to learn how to start on hills. You
learn to actually use excess engine power by riding steeper sections
faster rather than developing an efficient riding style. You learn to
simply ride straight through potholes even uphill, with thick tires and
suspension instead of cleverly avoiding them to save energy. Etc.
>>
>>> raises folks fitness
>>> level
>>
>> Au contraire, switching from bicycles to e-bikes lowers people's
>> fitness. Just as it takes time to get fit through intensive daily
>> cycling, sometimes years, it doesn't happen overnight that you become
>> unfit if you let the motor do most of the work. It happens so
>> insidiously that people don't notice it until it's too late.
>>
>That isn’t what I meant ie means for example that folks can ride a 20 mile
>MTB ride without being done for days at all, though some folks apparently
>do use them for training as it’s lower intensity and all that.
This is neither quantified, measured nor likely. It's simply a beautiful
narrative that accompanies self-deception.
>>
>>> and makes very steep technical climbs easier though by no means just
>>> doable, I can still clear stuff they can’t and so on.
>>
>> They most probably wouldn't, when using offroad motorcycles or their
>> car, either. This proves nothing.
>>
>> <
https://dirtbikemagazine.com/10-best-motocross-bikes-ever/>
>>
>>
>Well it’s shows that the bikes broadly have similar capabilities, ie riding
>with mates on E-bikes is not like riding with motorbikes really isn’t.
Who cares? That's a red herring. Motorcycles have capabilities,
e-bikes have capabilities, but bikes don't have capabilities. People
have or develop capabilities - or don't.
I've never seen a bicyle advertised with
Max. support level** (%) 340 %
Maximum possible drive torque (Nm) 85 Nm
Max. support up to 25 km/h
Smart Walk Assist with Hill Hold yes
Rated continuous output 250 W
Maximum power 600 W
Max. power at a cadence of 70 rpm 600 W
Max. Power-to-weight ratio 207 W/kg