Orbea Gain D50 ( User learning and experiences )

[AntonioAlfaro]

Thanks ngg and Stefan for your comments. In fact I am thinking about developing a new chapter on how to optimize the mass parameter on an E bike once I finish developing this proposal on how to customize assistance levels in an optimal and structured way.
By the way ngg, I really like those images, it seems to be a beautiful place to practice cycling.

 

[AntonioAlfaro]

The purpose of all this elaboration of ideas is to conclude in a methodology that allows us to personalize our levels of assistance in the E bike, in this way we will be optimizing the use of the finite energy available in the battery.
For this development, we are using a stock Orbea Gain D50 E-bike, so since this bike has a mass of 15 Kg, and having established that from 8 Kg onwards we are going to take it as a dead mass (something like we fattened Delta Kg ) to which we will take into account in the new power budget. Let's see.
How much power do those 7 Kg require to perform with a W/Kg=3 power profile?
Answer : 21W
These 21 W must be supplied by the battery. But this is not all. We will see how to propose the power budget to define our assistance levels (assistance levels are personal, not generalized).
When we cycle, we can find very varied elevations of the route we follow. So if the slope is large we will need more power assistance than if the slope were small. My experience using E Bike led me to establish and associate the 3 levels of assistance to 3 ranges of slopes on the route. So I will use:
Level L0 (no assistance) when the slope of the route is in the negative range or from 0% to 4%.
Level L1 when the slope of the route is in the range of 4% to 7%.
Level L2 when the slope of the route is in the range of 8% to 11%.
Level L3 when the slope of the route is in the range of 12% and above.
Knowing how to use the assistance levels when on the road, what remains for us is to set custom values for each of those assistance levels.
I will continue in the next few days..

 

[ngg]

I handle that intuitively. From my experience:
- It is important to maintain the cadence at an appropriate level for the cyclist (may be 60, 70, 80, 90, but not recommended below 55 RPM).
- When I can't maintain the cadence then I reduce the speed on the rear derailleur.
- If reducing the speed does not help maintain the cadence, I turn on the 1st level of motor assistance (if the motor "takes" me, I change the motor map and reduce the power for that level of assistance).
- When the cadence maintenance problem occurs again, I switch the assistance level to 2 and 3, respectively (if the motor "takes me", I change the motor map and reduce the power for that assistance level).
- When I feel relieved to ride a bike, I reduce the level of assistance, all the way to the 0th level.
Simple, isn't it!

 

[AntonioAlfaro]

Earlier I discussed the use of assist levels. My proposal for the use of assistance levels is based on ranges of terrain slope. What it means is that the steeper the terrain, the higher the level of assistance will be applied.
We are going to advance in the development of this methodology, establishing the "watts" required at each level of assistance, for this we are going to take a hypothetical case: cyclist "X" has a mass of 65Kg and his FTP is 195 W. in other words, its power profile W/Kg = 3, means that its condition is "good".
After many routes and measurements in different topographies and route distances, I have come to the conclusion that L1 should provide up to 25% extra power compared to the cyclist's FTP power, for W/Kg =3.
L2 should deliver up to 45% extra power, and L3 up to 70%.
So for the hypothetical example of cyclist "X", the assistance levels should be customized to the following values:
L1=195x25%=49W
L2=195x45%=88W
L3=195x70%=137W
Since cyclist "X" uses an Orbea Gain D50 that has an additional 7Kg mass than a normal road bike, he will need to use the assistance levels as well to supply power to those extra 7Kg that he did not have before. So we need to make a small adjustment to the calculation:
L1=(195+7)x25%=50W
L2=(195+7)x45%=91W
L3=(195+7)x70%=141W
With these values, rider "X" can now go to the Mahle app and customize his assistance levels in an optimized way.

The big question is how do we adjust the assist levels for a rider whose power profile W/Kg<3.
We will analyze it in the following days.

 

[AntonioAlfaro]

Let's define the "Y" cyclist who is out of shape and let calculate his custom assistance levels. The power profile of rider "Y" is W/Kg=2.3 and the rider's mass is 75Kg which means his FTP is only 173W.
This rider is going to need permanent power assistance to level out his power profile at 3 and a bit more to tackle the terrain slope.
Let's calculate what would be the total power required so that W/Kg =3.
(75Kg cyclist + 7 Kg extra from the Orbea) x 3= 246W
173 W out of 246 W, are provided by the cyclist and the difference must be provided permanently by the Ebike power assistance.
(246W-173W)=73W must be provided permanently.
Now we can calculate the attendance levels:
L1=73W+(246)x25%=134.5W
L2=73W+(246)x45%=183.7W
L3=73W+(246)x70%=245.2W
With these values, rider "Y" can now go to the Mahle app and customize his assistance levels in an optimized way.

I will continue in the next few days..

 

[Stefan Mikes]

You have to make a calculation for a 90 kg rider with an FTP of 80 W, too

 

[AntonioAlfaro]

Hi Stefan, I will do it in the next days.

 

[AntonioAlfaro]

Let's not forget that the power available in the E-bike battery is a finite resource and that it will allow us assistance with certain limitations. Next we are going to use the cyclist exercise "Y" and its power assistance levels to analyze extreme possible scenarios.
Scenario 1: we are going to assume that the "Y" cyclist moves only and always on flat ground, that is, 0 to 3 degrees of slope. Under this assumption, it will only require 73W of assist power at all times. Those 73W will lead to an equivalent W/Kg power profile of 3. In this scenario, and considering that the Orbea Gain battery capacity is 240W/h, cyclist "Y" could be assisted by at least 3 hour and 17 minutes. In this hypothetical scenario L1=L2=L3 should be customized to 73W.
Scenario 2: Let's assume that the cyclist "Y" always moves only and always on flat terrain with a slope between 4 and 7 degrees. Under this assumption, it will only require 134.5 W of assistance power at all times. Those 134.5 W will lead to an equivalent W/Kg power profile of 3.
Cyclist "Y" may be assisted for at least 1 hour and 47 minutes. In this hypothetical scenario the custom assistance levels would be L1=L2=L3= 134.5W
Scenario 3: Let's assume that the cyclist "Y" always moves only and always on flat terrain with a slope between 8 and 11 degrees. Under this assumption, it will only require 183.7 W of assistance power at all times. Those 183.7 W will lead to an equivalent W/Kg power profile of 3.
Cyclist "Y" may be assisted for at least 1 hour and 18 minutes. In this hypothetical scenario the custom assistance levels would be L1=L2=L3= 183.7W
Scenario 4: Let's assume that cyclist "Y" moves only on flat terrain with a slope above 12 degrees at all times. Under this assumption, it will only require 245.2 W of assistance power at all times. Those 245.2 W will lead to an equivalent W/Kg power profile of 3.
Cyclist "Y" may be assisted for at least 58 minutes. In this hypothetical scenario the custom support levels would be L1=L2=L3= 245.2W

Reality:
We have analyzed hypothetical scenarios for cyclist "Y" in order to get an idea about the duration times and the importance of managing the finite energy of the battery.
But the truth is that in real life, cyclist "Y" will face terrain with very varied altitudes, and for that his personalized assistance levels that we already calculate are:
L1=134.5W
L2=183.7W
L3=245.2W
these levels will be at his/her disposal to use them as the case may be.

How long will the available battery power last? The 240W/H will run out in how long?

We will discuss it soon.

 

[ngg]

I think the initial assumptions are wrong.

Namely, the fact is that the average cyclist (power = 3x weight) can generate 246 watts (as you calculated), but this does not mean that on flat terrain without major climbs this average cyclist will spend all 246 watts. It probably won't take more than 80 watts to ride a bike on flat terrain. And everything else up to 246 watts will remain in reserve, to master larger climbs or to master the length of the ride.

So, in Scenario 1, the battery will last (theoretically) indefinitely, because that cyclist Y, although reduced power, still has at least twice the power needed for a short ride on flat terrain without uphill.

I think you need to start with the estimated power needed for each different terrain, and then calculate how much assist it takes for a cyclist Y to overcome that terrain.

Another problem is that in calculations you exceeded the maximum permanent limits for the 1st and 2nd degree of assistance, from 100 and 175 watts.

 

[AntonioAlfaro]

I think the initial assumptions are wrong.

Namely, the fact is that the average cyclist (power = 3x weight) can generate 246 watts (as you calculated), but this does not mean that on flat terrain without major climbs this average cyclist will spend all 246 watts. It probably won't take more than 80 watts to ride a bike on flat terrain. And everything else up to 246 watts will remain in reserve, to master larger climbs or to master the length of the ride.

So, in Scenario 1, the battery will last (theoretically) indefinitely, because that cyclist Y, although reduced power, still has at least twice the power needed for a short ride on flat terrain without uphill.

I think you need to start with the estimated power needed for each different terrain, and then calculate how much assist it takes for a cyclist Y to overcome that terrain.

Another problem is that in calculations you exceeded the maximum permanent limits for the 1st and 2nd degree of assistance, from 100 and 175 watts.

Hello NGG, I am glad to know that my post finds space for observations, discussion and improvement.
You are correct with your comment, but as I have mentioned these extreme hypothetical scenarios do not exist in reality, they are only for educational purposes and to show how the battery power reserve is drastically reduced depending on the level of assistance used. I totally agree that the times indicated in each imaginary scenario are theoretically the minimum (note that I always use the word "at least").
In the next days I will continue commenting about the battery time estimation in each level. Thanks again for your comments.

 

[ngg]

I suggest you start from the available CRR data. Your Hutchinson Fusion 5 Performance TLR 700x30 road tires require over 28 watts (for two tires) to maintain a speed of 29 kph (18 mph) with a load of 42.5 kg (94 lbs). Alternatively, Panaracer Pasela PT 700x38 city/touring tires require over 38 watts (for two tires) under the same conditions. These are initial values that can apply to quality flat roads without any uphills.

So, the base values for quality flat roads without uphills are 30 and 40 watts, depending on the type of tires and for a cyclist weighing 70 kg. And here, obviously, he doesn't need any assistance, not even Stefan, who thinks that his FTP = 80 watts.

Now to these values should be added the watts needed to overcome aggravating circumstances, such as (smaller and larger) uphills and the weight of the cyclist (actually, the weight load of the tire), above all else.

 

[Stefan Mikes]

So, the base values for quality flat roads without uphills are 30 and 40 watts, depending on the type of tires and for a cyclist weighing 70 kg. And here, obviously, he doesn't need any assistance, not even Stefan, who thinks that his FTP = 80 watts.

Well, ngg. My Vado SL weighs some 18 kg. Yes I can ride it unpowered. However, my low FTP makes me ride very slowly that way. I can even ride my 24+ kg big Vado unassisted. However that happens at speed of 12-14 km/h and the whole point of riding e-bike is missed...

 

[ngg]

Well, ngg. My Vado SL weighs some 18 kg. Yes I can ride it unpowered. However, my low FTP makes me ride very slowly that way. I can even ride my 24+ kg big Vado unassisted. However that happens at speed of 12-14 km/h and the whole point of riding e-bike is missed...

According to CRR data, you (95 kg) with your Vado SL (18 kg) should easily reach 29 kph on a flat road (without uphills) without any motor assistance, as it does not require 80 watts.

If you need motor assistance, then something is wrong, either with the bike, the tires or with your physical conditions.

I’m a little heavier (99 kg), my Vibe is a little lighter (15 kg). But all in all it’s the same, and I don’t have that kind of problem. I can easily reach a speed of 29 kph on quality flat roads, even with Kenda Kwick700 tires, which are probably at least 20 watts (for two tires) more demanding than the Panaracer Pasela, e.g.

 

[Stefan Mikes]

with your physical conditions.

This.
Theory is theory but... I have Strava records for my traditional hybrid bike rides before my ailments developed. My typical average speed on a 50 km trip was 16-17 km/h. Strava was estimating my power as 40-50W. I could never reach the speeds like 29 km/h on the flat, and it was 21 km/h maximum. I was 53 at that time.

I think practice is very different from the theory. Now I have a power meter as the part of my e-bikes, and a wealth of statistical data. I would say riding e-bikes has improved my physical shape! More leg power, endurance, etc.

The stats of my yesterday's upwind ride. All measured by the 45 km/h Vado. The average battery consumption was 11.16 Wh/km. My bike + cargo weighed 30 kg.
I can also share the stats of my downwind ride.

 

[ngg]

I record approximately the same data as you (except for the cadence - my maximum is less than 100). I'm a little older than you, and I have high blood pressure too. Sorry Stefan, but I'm still confused. Maybe one day I'll figure out what it's all about. For now, let it stay that way. Good luck.

 

[Stefan Mikes]

I'm 60, to be clear.

 

[ngg]

I'm 60, to be clear.

and I am 61

 

[AntonioAlfaro]

I like to see all these comments and points of view about this new and interesting topic. All comments are welcome and will be attended.

 

[AntonioAlfaro]

I'm going to pause my development to analyze the case that Stefan shows. A few days ago I myself was surprised by the data that Stefan showed and I asked him for confirmation of it, but like NGG, there is something suspicious that seems to disagree with the theoretical and the real that I have seen in my long years in cycling .
To approach the case in a methodical way, I would like to have an answer from you Stefan (if you agree) of the following questions:
1) When you say "I have Strava records for my traditional hybrid bike...". Can you tell me what type of bike you are referring to?
2) The records you have on Strava from which you conclude that your FTP is 80 W, are you using which bike?
3) In the Strava dashboard you can find the Power Curve in the Training tab. Please check FTP estimate. Could you send me that graph?
4) Could you send me an image of the altitude of your last trip of 34.09 km?
5) When you mention "Now I have a power meter as the part of my e-bikes" could you clarify a little more what it is about?

I look forward to your responses for further assessments. Thank you very much for your contributions.

 

[Stefan Mikes]

Let me start with a general explanation (your point 5).
Specialized Turbo e-bikes are divided into "full power" and "SL" (low power) groups; I own a representative of each group. All Specialized e-bikes are equipped with mid-drive motors, torque & cadence (and more) sensors as well as they boast Bluetooth and ANT+ connectivity. Meaning, the rider's power is being measured together with the electrical assistance power (that we know how to convert to the mechanical motor power). The e-bike, rider, heart-rate, and ride data (generally around 50 parameters) are made available to the outer world.

An independent Italian app BLEvo can monitor all these parameters online during the ride, record them, and present in form of reports, maps and Excel sheet for the most detailed post-ride analysis. If required, BLEvo will export the post-ride data to Strava for further analysis. The user can also study the most detailed ride data on the ride map (each ride point has the full data record), in reports, or in Excel.

1. Old Strava records refer to an 18 kg flat bar 28" wheel traditional bike. See the picture in the attachment.
2. Weighted average power of the rider of around 80 W is reported by Strava for long rides on both my Vado (full power) and Vado SL (low power) e-bikes.
3. The Power Curve for a low power Vado SL and full power Vado are attached.
4. Altitude chart for the 43.09 km ride is attached. 48 m elevation gain means flat terrain with perhaps two overpasses on the way.