Sorry - question about support level

[Stefan Mikes]

nice average speed for a sustained distance! has anyone else ever done that segment - it says 1 attempt by 1 person?! a flat road like that here would have a zillion attempts!

Strava continually searches through its database to find more riders. So far, it also found my brother riding together with me (and "That Woman" on an XC bike) for Jun 13th, 2021. We were moving at only 27.8 km/h! I hope Strava would find more competitors. That road is a popular battlefield for roadies, especially those riding from the west with tailwind. Strava could find many e-bikers riding in the opposite direction. Typically, the leaderboard is filled overnight.

 

[Stefan Mikes]

Great job Stefan! Now if you have recuperated from that effort I have another stupid question re: support & watts. On the Mission Control app under “my rides” it shows among other things “total consumption“ in watts, or what I assume is watts. It will read something like: “110.00wh”. Does that reference the average watts put out by the rider during that particular ride or something else? Thanks in advance.

As mschwett said. Only he refers to an SL battery, and I'm not sure what e-bike you're riding?

I love the BLEvo app (will not work with 2022 Spec Mastermind e-bikes). Here's the full ride report from the second segment of my ride of today (note: the elevation and gradient data here are really wrong!). BLEvo also creates a detailed map of your ride will ALL ride parameters for any single trip point as well as locations and duration of any stops you had on the ride.
-----------------
Feb 20, 2022 12:36:55 - Shimanów - Leszno - Pilaszków - Płochocin (2nd Battery) [DOWNWIND]

- Movement time: 1:18:44
- Total kilometers: 37.33 km (▲ 1.7 km | ▼ 2.2 km | = 33.5 km)
- Average speed: 28.5 km/h
- Total ascent GPS: +41 m
- Battery consumed: 73% (370Wh)
- Average consumption per KM: 9.91 Wh/km
- Percentage of average assistance: 72.8%
- Wh ride: 455.8Wh
- Biker: 18.8% (85.8Wh)
- Battery: 81.2% (370Wh)

------------------------------------------------------

FULL STATISTICS:

Firmware: 7.32.0
Bike parameters:
Advanced user - 46/60/100 PP 45/60/100

Percentage of average assistance: 72.8%
- ECO: 46.0%
- TRAIL: 60.0%
- TURBO: 100.0%
Manual assistance changes: 7
- TRAIL: 4
- TURBO: 3

Date time:
- Start: Feb 20, 2022 12:36:55
- End: Feb 20, 2022 14:51:34

Total time: 2:14:39
- Movement time: 1:18:44 (58.5%)
- Stop time: 0:55:55 (41.5%)

Movement time: 1:18:44
- ECO: 01:40 (2.1%)
- TRAIL: 55:40 (70.7%)
- TURBO: 21:22 (27.1%)

Movement time: ▲ 0:04:30 | ▼ 0:05:36 | = 1:08:36
- ECO: ▲ 0:00:14 | ▼ 0:00:55 | = 0:00:31
- TRAIL: ▲ 0:03:45 | ▼ 0:04:11 | = 0:47:44
- TURBO: ▲ 0:00:31 | ▼ 0:00:30 | = 0:20:21

GPS Coverage: 100%

Total kilometers: 37.33 km
- ECO: 0.16 km (0.4%)
- TRAIL: 25.13 km (67.3%)
- TURBO: 12.05 km (32.3%)

Total kilometers: ▲ 1.7 km | ▼ 2.2 km | = 33.5 km
- ECO: ▲ 0.0 km | ▼ 0.1 km | = 0.1 km
- TRAIL: ▲ 1.5 km | ▼ 1.8 km | = 21.8 km
- TURBO: ▲ 0.2 km | ▼ 0.3 km | = 11.6 km

Total kilometers with assistance: 30.00/37.33 km (80%)
- ECO: 0.02/0.16 km (14%)
- TRAIL: 19.20/25.13 km (76%)
- TURBO: 10.78/12.05 km (89%)

Battery:
- Start: 100% (502Wh)
- End: 27% (132Wh)
- Consumed: 73% (370Wh)
- ECO: 0.1% (0Wh)
- TRAIL: 44.8% (228Wh)
- TURBO: 28.1% (143Wh)

Average consumption per KM: 9.91 Wh/km
- ECO: 3.61 Wh/km
- TRAIL: 9.03 Wh/km
- TURBO: 11.82 Wh/km

Range: 13 km (▲ 14 m)
- TRAIL: 14 km
- TURBO: 11 km

Battery temperature:
- Min: 11°C
- Max: 18°C
- ∅ : 14°C

Motor temperature:
- Min: 10°C
- Max: 35°C
- ∅ : 27°C

Average speed: 28.5 km/h
- ECO: 5.6 km/h
- TRAIL: 27.1 km/h
- TURBO: 33.8 km/h

Average speed: ▲ 22.4 km/h | ▼ 23.1 km/h | = 29.3 km/h
- ECO: ▲ 9.6 km/h | ▼ 4.4 km/h | = 5.9 km/h
- TRAIL: ▲ 23.3 km/h | ▼ 26.2 km/h | = 27.5 km/h
- TURBO: ▲ 21.4 km/h | ▼ 31.5 km/h | = 34.2 km/h

Maximum speed: 44.9 km/h
- ECO: 13.6 km/h (14:12:46 - km 21.97)
- TRAIL: 41.4 km/h (13:27:22 - km 20.07)
- TURBO: 44.9 km/h (14:23:36 - km 26.98)

Average cadence: 68 rpm
- ECO: -- rpm
- TRAIL: 66 rpm
- TURBO: 74 rpm

Maximum cadence: 94 rpm
- ECO: 47 rpm (12:37:36 - km 0.02)
- TRAIL: 84 rpm (13:27:14 - km 20.00)
- TURBO: 94 rpm (14:41:07 - km 32.70)

Kcal consumed: 335 Kcal
- ECO: 1 Kcal
- TRAIL: 217 Kcal
- TURBO: 118 Kcal

Average Biker Power: 91 Watt
- ECO: -- Watt
- TRAIL: 86 Watt
- TURBO: 100 Watt

Maximum biker power: 173 Watt
- ECO: 95 Watt (12:37:36 - km 0.02)
- TRAIL: 166 Watt (13:27:17 - km 20.03)
- TURBO: 173 Watt (14:26:38 - km 28.92)

Average Motor Power: 385 Watt
- ECO: 219 Watt
- TRAIL: 347 Watt
- TURBO: 466 Watt

Maximum motor power: 663 Watt
- ECO: 237 Watt (12:37:36 - km 0.02)
- TRAIL: 663 Watt (12:55:14 - km 8.64)
- TURBO: 635 Watt (14:25:46 - km 28.40)

Total Wh biker: 85.8 Wh
- ECO: 0.2 Wh (0.2%)
- TRAIL: 55.5 Wh (64.6%)
- TURBO: 30.2 Wh (35.2%)

Total Wh motor: 372.9 Wh
- ECO: 0.6 Wh (0.2%)
- TRAIL: 228.7 Wh (61.3%)
- TURBO: 143.6 Wh (38.5%)

Maximum altitude: 125 m
Minimum altitude: 100 m

Total ascent GPS: +41 m
- ECO: +17 m (41.4%)
- TRAIL: +24 m (58.6%)
- TURBO: +0 m (0.0%)

Total descent GPS: -31 m
- ECO: -25 m (80.6%)
- TRAIL: -6 m (19.4%)
- TURBO: -0 m (0.0%)

Uphill altitude gain per hour: 554.4 m/h

Downhill altitude gain per hour: 335.4 m/h

Maximum gradient: 19.3%
- ECO: 14.2% (14:14:11 - km 22.08)
- TRAIL: 19.3% (14:14:17 - km 22.09)
- TURBO: 2.7% (14:44:01 - km 34.12)

Minimum gradient: -9.2%
- ECO: -6.2% (14:13:49 - km 22.03)
- TRAIL: -9.2% (14:16:40 - km 23.02)
- TURBO: -2.2% (14:41:50 - km 33.04)

 

[Jorge M]

Thanks mschwett & Stefan! I clearly didn’t know what I was looking at. I guess I need the BLEvo app to really tell me about my watts vs the bike’s. I have a Creo btw.

 

[TXPearl]

...
your strategy of keeping support low but max power high can be a good one, although it results in inconsistent and unpredictable battery usage. the harder you pedal, the more battery you use. if you're pedaling hard to go fast (rather than uphill) you'll eat battery very fast without actually going much faster since wind drag is the CUBE of speed - it's 8 times as much at 20mph as it is at 10mph. weight matters almost none once you're already moving.
...

Great post, but isn't aero drag relative to the SQUARE of speed? Either way, the point still stands.

New here and long-time cyclist and data hound, but new to e-biking. Just got a Turbo Levo SL last week so exploring/tweaking power settings. Seems most (all?) here are riding Creos and other road bikes, but I assume much of the logic applies to the Specialized eMTB system as well.

 

[mschwett]

Great post, but isn't aero drag relative to the SQUARE of speed? Either way, the point still stands.

New here and long-time cyclist and data hound, but new to e-biking. Just got a Turbo Levo SL last week so exploring/tweaking power settings. Seems most (all?) here are riding Creos and other road bikes, but I assume much of the logic applies to the Specialized eMTB system as well.

nope. cube. many sources for this - double speed, 8 times the drag. this is why it’s a fool’s errand to try and get a “bicycle” (as opposed to a motorcycle) to go very fast for long distances, particular an upright model with an upright rider. aero road bikes with skinny tires, deep profile wheels, streamlined helmets, riders in lycra etc help greatly reduce the drag, but the relationship to speed is still the same. you’re just multiplying a smaller number by 8 to double the speed lol.

When Cycling Becomes a Drag: The Aerodynamics of Cycling - Interesting Engineering

Cycling, like other modes of transport, has its fair share of aerodynamic drag.

amp.interestingengineering.com

 

[TXPearl]

From your source....

As you can see from the equation, aerodynamic drag increases as the square of the velocity. This means that if you double your speed, you will need four times the energy to overcome the drag.

Maybe the 8x includes increases in other forces....friction?? Doubtful it's that much.

 

[mschwett]

From your source....

As you can see from the equation, aerodynamic drag increases as the square of the velocity. This means that if you double your speed, you will need four times the energy to overcome the drag.

Maybe the 8x includes increases in other forces....friction?? Doubtful it's that much.

drag force is squared. force required to overcome the drag at twice the speed is cubed. (i agree the text from interesting engineering is unclear.)

one can also plug various speeds into bikecalculator.com to see the results of various combinations, confirming that it's approximately 8 times the energy to double the speed as drag becomes the primary factor. at lower speeds it's quite a bit less, and at high speeds still a bit less because the other factors - friction within the bike, rolling resistance, movement of the body and who knows what else, don't increase as fast. but the vast majority of the work is to overcome drag at those speeds. from 20 to 40 it's 6.5x.

 

[TXPearl]

Funny, I went to the same site and got similar results. If you input very extreme speed values you get closer to 8x, as friction becomes less material to total forces. In the real world, simply doubling speed is somewhat extreme, but this exercise makes you realize why road cyclist are hyper-sensitive to a 5mph wind.

Of course, if you travel twice as fast, you cover a given distance in half the time, so back to 4x Wh used by your legs/battery.

 

[mschwett]

Funny, I went to the same site and got similar results. If you input very extreme speed values you get closer to 8x, as friction becomes less material to total forces. In the real world, simply doubling speed is somewhat extreme, but this exercise makes you realize why road cyclist are hyper-sensitive to a 5mph wind.

Of course, if you travel twice as fast, you cover a given distance in half the time, so back to 4x Wh used by your legs/battery.

very true! and since it’s not quite 8x in practice, it’s probably not quite 4x either, so perhaps 3 times the power per mile to double the speed, but one needs a very high capacity battery and bike to sustain those sorts of power levels, and the proportional contribution of the human rider becomes increasingly small. for a 200w load even a casual rider can easily contribute half, but for a 800w load they’re only contributing 1/8th, so 100w needed from the battery goes to 700w, and we’re back to 7x the battery per mile

 

[Stefan Mikes]

Air drag (force) is the square function of speed. Power to overcome the air drag is the cube function of speed.
You two guys were both right.
And all modern Specialized e-bikes including e-MTBs use the same Assist Level/Max Motor Power concept. However, e-MTBs get more options. For example, Acceleration is how quickly will the motor activate when you push the pedal (it can be an immediate action) and another mode (I can't remember the name) that is for riders preferring crank spinning to pedal mashing.

 

[Merle Nelson]

Phenomenal information in this thread.

I just get on the bike with two round wheels and turn the spinny thing to move forward.

Sounds like there is a world more that I could understand and benefit from.

 

[Stefan Mikes]

Phenomenal information in this thread.

I just get on the bike with two round wheels and turn the spinny thing to move forward.

Sounds like there is a world more that I could understand and benefit from.

All such information is vital for assistance planning for long rides, Merle. I was to set off for a 50 mile ride on last Sunday. I knew I would need to counter a 17 mph headwind on the outward leg of my trip. I knew the initial charge of my two batteries as exact figures beforehand. And I decided I could make the trip if the assistance level would be (full power Vado) of 60% with the Maximum Motor Power capped at 60%.

Outcome:

• Outward leg of the trip: 95% of the Battery #1 consumed, average speed of 14.1 mph
• The return leg of the trip (downwind): 73% of the Battery #2 consumed, average assistance of 72.9%, average speed of 17.6 mph with the maximum speed of 28 mph on a sprint.

If not the understanding of the phenomena occurring on e-bike rides, I would either return on my own leg power, or would come back terribly tired because of too low assistance upwind.

 

[kahn]

All such information is vital for assistance planning for long rides, Merle. I was to set off for a 50 mile ride on last Sunday. I knew I would need to counter a 17 mph headwind on the outward leg of my trip. I knew the initial charge of my two batteries as exact figures beforehand. And I decided I could make the trip if the assistance level would be (full power Vado) of 60% with the Maximum Motor Power capped at 60%.

Outcome:

• Outward leg of the trip: 95% of the Battery #1 consumed, average speed of 14.1 mph
• The return leg of the trip (downwind): 73% of the Battery #2 consumed, average assistance of 72.9%, average speed of 17.6 mph with the maximum speed of 28 mph on a sprint.

If not the understanding of the phenomena occurring on e-bike rides, I would either return on my own leg power, or would come back terribly tired because of too low assistance upwind.

I have to admit my head is spinning, like the pedal thingie @Merle Nelson uses to move forward. I need you along since most of this stuff is just over my old head. Besides I'm pretty pooped packing up a dining room with about 200 chatzkies/tchotchke (Yiddish tshatshke trinket, from obsolete Polish czaczko) so that the room can be stripped of wallpaper after 34 years. Yes, I realize many of you are not even 34!!!!

I do know that just winging it, last summer we managed 53 miles and about 3,000 feet of climbing using the main and range extender. I guess I'd like to be able to plan better but ... Hence, the second range extender!

 

[Gbike]

The one thing this thread has allowed me to do is USE IT. No sense leaving energy in the battery if there is a more fun ride to be had

 

[mschwett]

if anyone's head isn't spinning, here's an interesting question: how accurate are these formulas when compared to actual real world cycling?

surprisingly (to me) well it turns out. especially on the gravity (climbing) side. still very good when drag is the main factor.

here's a short climb in my neighborhood. bike calculator prediction based on my speed is that it would take 246 average watts of power to make the climb. actual value recorded by my creo? 244 watts average. a vanishingly small error, especially given a few pounds of variation and slightly inaccuracies in the grade measurements. in this case, i actually doublechecked them against a contour survey of the area and found it within 5%.

the difficulties in approximation get a little more difficult when the subject is drag rather than gravity. here are two 14-15 minute lapping sessions on a public cycle track in golden gate park. since it's a loop, wind is cancelled (although that pesky square/cube function will still penalize wind to some extent, as power used to accelerate faster still with a tailwind is diluted), and in any case it was not a very windy day.

here the prediction is for 21.5 mph and 20.2 mph for the two rides, respectively, and the actual values are 21.0 and 19.8, respectively, ,for an error of a little over 2 percent. given that GPS significantly undercounts distance on curves (bike travel in curves, not a straight line between points around a curve) i'd guess the actual error is more like a little over 1 percent, likely indicating that the power meter in the bike isn't perfect and i have more drag than the bike calculator assumes, which isn't surprising! my bike has 32mm tires and i don't wear lycra jerseys

nonetheless, these three examples are all impressively close to real world measurements. for those who are interested in the subject, bikecalc makes it very easy to predict range and speed for your e-bike rides if you know your human contribution! (for all these rides, my creo's motor was off)

 

[WiggityZwiggity]

That's very easy to explain. The Support parameter means how much your leg input power is amplified by the motor. The maximum mechanical amplification is 1.8x (that's what is delivered to the drivetrain). 15% support means 0.15 * 1.8 = 0.27x amplification. Say your leg power is 150 W, then the motor will deliver 0.27 * 150 = 40.5 W to the chainring, and you will add your own 150 W.

Max Motor Power is a cap on the mechanical power the motor is allowed to assist you. 100% Max Motor Power is 240 W for the SL 1.1 motor. 50% of Max Motor Power is the motor is allowed to deliver up to 120 W of mechanical assist.

These two parameters are independent.

For instance:

• Support 100%
• Max Motor Power 50%
• Your leg input power 150 W.

The leg power should be amplified to 150 * 1.8 = 270 W. However, you capped the Max Motor Power at 120 W, so no more than 120 W mechanical would be provided by the motor to the drivetrain.

Or,

• Support 15%
• Max Motor Power 100%
• Your leg power input 150 W.

As shown above, the motor will assist you with 40.5 W but theoretically might deliver up to full 240 W of assistance.

Or,

• Support 15%
• Max Motor Power 15%
• Your leg power input 150 W.

The Support expects to assist you with 40.5 W. The cap on the motor power is 0.15 * 240 W = 36 W. If you set the system as above, the motor will only provide up to 36 W.

Sorry to hop on an older post. How does torque apply into this equation of understanding assist levels? Also curious around how nominal vs. peak power play into this? I feel like I read that the older Comos/Vados had 500 watts peak power but 250 nominal, the newer 2022 models only list 250, do those still have 500 watts peak?

 

[Stefan Mikes]

Sorry to hop on an older post. How does torque apply into this equation of understanding assist levels? Also curious around how nominal vs. peak power play into this? I feel like I read that the older Comos/Vados had 500 watts peak power but 250 nominal, the newer 2022 models only list 250, do those still have 500 watts peak?

Torque * rotational speed = power. Therefore the more power at given motor rpm the higher the torque. (We only do not know the rotational speed of the motor).

250 W is "continuous rated power for 30 minutes" that is the mechanical power that could be collected from the motor without overheating it. (It is more legal than a technical term). The Maximum Motor Power or Peak Power is far higher for so-called full power mid-drive e-bike motors. The peak power of Specialized full power motors depends on the motor version (therefore - the e-bike version). Rest assured the Specialized 2.2 motor found in version 5.0 of new Vado and Como pumps 565 W of mechanical Peak Power, with the maximum torque of 90 Nm.

 

[WiggityZwiggity]

Torque * rotational speed = power. Therefore the more power at given motor rpm the higher the torque. (We only do not know the rotational speed of the motor).

250 W is "continuous rated power for 30 minutes" that is the mechanical power that could be collected from the motor without overheating it. (It is more legal than a technical term). The Maximum Motor Power or Peak Power is far higher for so-called full power mid-drive e-bike motors. The peak power of Specialized full power motors depends on the motor version (therefore - the e-bike version). Rest assured the Specialized 2.2 motor found in version 5.0 of new Vado and Como pumps 565 W of mechanical Peak Power, with the maximum torque of 90 Nm.

View attachment 114914

Obviously less torque on the 2.0 motor found in the 4.0's but presumably same peak power?

 

[Stefan Mikes]

Obviously less torque on the 2.0 motor found in the 4.0's but presumably same peak power?

Expect 450 W or so. The torque for the same type of the motor is proportional to the motor peak power. 2.0 is expected to be 80% of the 2.2.