V11 Uphill - What's the limit?

[That Guy]

Hi EUC Community! 😊

I am about to purchase V11. I have chosen it based on (my perception of it meeting) the following criteria: 1) ability to climb hills without cutting off/burning/failing, 2) ability to ride in the rain, 3) overall build quality.

I am particularly concerned about the first and most important criterion – hill climbing ability. I live on a 200m (about 650 feet) with a steady steep climb over about 1.2km (0.75mile) from about the sea level. My office is under the hill. With all the gear I am probably about 100kg (220lbs).

So, before I commit to buy, I thought to check with you guys that I am not mistaken and it will work for me:

Question 1: will I be able to ride up my hill every day without stopping and let the wheel cool?

(Question 1a: will I be able say, once a week, ride up a taller hill: 650m (0.4mile) over 6km (3.7mile)?)

Question 2: as my office is down the hill, I probably will have to charge the wheel in the office because I will not be able to ride it down hill fully charged, am I right?

In other words - what are the limits of InMotion V11 in terms of hill climbing?

I am sorry, maybe this topic has been already fully covered in this forum, I just haven’t found a specific analysis of V11’s ability to climb hills. I watched the “Overheat Hill” video, which made me think V11 suits me perfectly. However, the riders might be lighter. Anyone has a similar experience or use of V11?

Thanks heaps!

[UniVehje]

Q1: yes

Q1a: yes. Overheat hill is way steeper than anything you might ever encounter. Steeper than it looks on video. That’s an extreme test. It the hill is paved or used by people normally, you can ride it with almost any modern wheel without problems. 

Q2: This will be same for all wheels. You can only brake by using regenerative braking and thus charging the battery. It doesn’t mean you don’t have any brakes when you are at 100 % battery. But if you charge to full, the wheel might start warning and tilting back before you reach bottom. Leave it at 95% and you’ll have a fully charged wheel at the office (rough estimate). The regeneration is not very efficient. If you suddenly get an overcharge warning, ride a few meters uphill and you use enough energy to go down a lot more. 

[That Guy]

Thanks UniVehje!

Q2 - understood, thank you.

Q1/1a - not yet... :-) Dunedin in New Zealand has the steepest street in the world, it's wild here, man!... :-) I spoke with someone recently about V10f and they tried, as an experiment, to ride up a hill with a similar gradient to mine and the V10f capitulated within a kilometre, sadly. So, V10f got out of my list. Of course, V11 has a bigger battery and a stronger motor. But the manufacturer is very conservative and they might have limited the V11 to some motherboard temperatures/current, etc. after that pre-production unit tested and failed by Marty Backe? Not sure...

On the overheat hill, are there anywhere descriptions of that hill profile? My daily commute will include (down and up) 20% gradient over 1.2 km. 

I guess, every wheel will capitulate either civilised way or with a smoke at some stage. Has anyone established the (production) V11's limit? ;-)

 

[gon2fast]

Is suspension a requirement? Seems like several non-suspended wheels will meet your expectations... and with much hesitation, an EX would fit.

Edited April 27, 2021 by gon2fast

[UniVehje]

5 hours ago, That Guy said:

Q1/1a - not yet... :-) Dunedin in New Zealand has the steepest street in the world, it's wild here, man!... :-) I spoke with someone recently about V10f and they tried, as an experiment, to ride up a hill with a similar gradient to mine and the V10f capitulated within a kilometre, sadly. So, V10f got out of my list. Of course, V11 has a bigger battery and a stronger motor. But the manufacturer is very conservative and they might have limited the V11 to some motherboard temperatures/current, etc. after that pre-production unit tested and failed by Marty Backe? Not sure...

On the overheat hill, are there anywhere descriptions of that hill profile? My daily commute will include (down and up) 20% gradient over 1.2 km. 

I guess, every wheel will capitulate either civilised way or with a smoke at some stage. Has anyone established the (production) V11's limit? ;-)

I get what you are saying. But I still will say that OHH is nothing like anything that is normally used by people. I don't remember what the gradient is but you will not find a paved road as steep. V10F was not limited by battery or motor nominal rating. It had too few MOSFETs and that is not a problem with V11. I really think that your hill will not be the factor you should base your decision on. All modern wheels will make it. 

[Tawpie]

13 hours ago, That Guy said:

My daily commute will include (down and up) 20% gradient over 1.2 km

20% gradient is steep and will be scary going down, wear butt protection (personal experience speaking). Here's some math dealing with taking a bike up the hill, it suggests that for a V11, 'power' shouldn't be a problem. In theory***. http://theclimbingcyclist.com/gradients-and-cycling-how-much-harder-are-steeper-climbs/

***: in theory, theory and practice are the same. but in practice...

Most 'wattage' ratings of electric motors state how much continuous power they can accept before the motor overheats. The controller might be expected to be able to outperform the motor, but that isn't true in most cases. Same can be said for the wiring from the controller to the motor, the wires are traditionally sized 'just barely' large enough. Be aware of your battery percentage when you start going up hill too, the high power demand will cause the battery voltage to sag which means each cell must supply more current which causes the battery voltage to sag—there is a limit on how low the voltage will be allowed to go before the wheel decides it's overpowered and stops balancing. And remember that an electric motor that is turning very slowly is effectively a short circuit, which wants to draw more current from the batteries which causes the battery voltage to sag which...

 

[RagingGrandpa]

One last thing that wasn't mentioned above: speed matters.

• Climbing slow (e.g. 10mph) is less stressful to the EUC.
• Descending at a moderate pace (e.g. 20mph) is less stressful to the EUC.

Your EUC will beep if it is overtemperature, or overvoltage. Respect the beeps.

Enjoy!

  

On 2/19/2021 at 10:06 AM, RagingGrandpa said:

Assuming rider+EUC = 100kg, consistent grade, 32km/h riding (20mph), and no prevailing wind: net energy becomes zero on a 15% grade.
It means: if you are dropping 1500m over a 10km ride distance, you use no energy from the battery pack.
Ride steeper than 15%, and you're charging the pack.

15% is really steep for a roadway.
Public roads in the US are generally limited to 12% grade.
There are some notable exceptions, such as 23% in the city of San Francisco, but they are not sustained for long distances.

So overall, I think it is a very tiny percentage of EUC riders that live on top of a ride route with a 15% grade. Most of us don't need to worry.
Respect the beeps!
Thankfully, there is an audible alert for pack overvoltage. If you hit the alarm, turn around and ride uphill for 1km, or do a few minutes of pendulum practice, then continue back down.

 

[That Guy]

Thanks everyone! Really appreciate your thoughts, guys.

R.Grandpa, yeah, I do expect maybe 15-ish mph speed uphill, not much more but probably not less either.

Tawpie, thanks for the article - good stuff. So where would V11 sit against those graphs for the 20% gradient? I guess the 2.2kW should be just enough to pull both me and the EUC ( up, but for how long? 1km? 2? 5?... 

To gon2fast: no, the suspension is not a requirement but I don't want to wait till V12 (plus don't want to get the first batch of it anyway ;-)). It does tempt me to think towards torquier options such as KS16X... I have never thought buying something may be such a research project! :-)

 

[Tawpie]

@That Guy  I know a V11 rider who tips the scales a bit above you, he was worried about hills (we have hills here, nothing like yours though) when he bought his wheel but has been totally happy so far... I'll ping him to see if he's ever tried something that steep for a km.

[Rich Sam]

Hey guys, I have lost weight down to 245-250ish from 283 when I bought the V11.  Trust me when I say it can handle weight.  Here is my last ride and check out elevation change.

https://euc.world/tour/597625986921141

 

 

[mrelwood]

13 hours ago, Tawpie said:

The controller might be expected to be able to outperform the motor, but that isn't true in most cases.

I guess you were still talking about electric motors in general. In the EUC side of things the “motor wattage“ is a strange number. For example, less is sometimes more, and seems it can be increased by just a firmware update, etc.

My wattage rant of the week:

 The value that is given as an EUC motor wattage seems to be closely related to the sustained output power of the controller + battery combo. Although, even that doesn’t always make much sense.

For example, V11 had a 2000W motor that was quietly increased to 2200W, and it has a 3000W controller that can peak at 5000W.

 The V10F also had a 2000W motor, but as we all know, the controller overheated easier than perhaps any other current production EUC. It does seem that the issue has been fixed though, but AFAIK it’s still not quite in the MSX/V11/18XL power group.

18XL got an actual motor upgrade to 2200W, but the general consensus seems to be that the old motor felt more powerful.

 Didn’t the 2000W MSX and 2500W MSP (HT) have the exact same motor?

I think it’s best to see the value as a ballpark figure, +- 20%.

Edited April 28, 2021 by mrelwood

[Tawpie]

17 hours ago, mrelwood said:

My wattage rant of the week:

I'm with you on ranting.

But I sort of gave up after living through marketing for cars, cigarettes, paper towels and pretty much everything else... I threw in the 'do I care at all' towel when computing devices switched from the messaging that more gigahertz was always better to more 'cores' was the only way to go. More watts—what does that really mean, really? It might be 'better' than not as many watts, but better in which regard? Doesn't necessarily mean you can go faster. Doesn't always mean you can accelerate faster. Doesn't even guarantee you have more safety margin. It might mean it's heavier or that it cost more to make but maybe not. Same with free-spin max speed... that's under firmware control to keep the motor from disassembling and has only a loose relationship to max speed under load.

A 750W horse can pull a plow (torque: +1), carry hundreds of pounds up crazy steep hills (load: +1, hill climb: +1), safely balance in snow, loose sand, mud and rocks (controller sophistication: +1, traction control: +1). It can launch itself 4' in the air over a fence and excels on the gnarliest singletrack (durability: +1). With the proper footwear (tires?) it rides like a horse on pavement and it's basically weather proof at the temperatures you and I would be out at (commuter use: +1, tire change: no points). Some can go 35+ mph (speed: no points because they can't go that fast for long, they overheat and their blood pumps fail and 'rims' tend to crack). It stops on a dime (braking: +1). It's exhilarating to ride (helmet still recommended: no points), and not prone to "Sorry, I didn't see ya mate" (traffic/pedestrian safety: +1, AVAS without BlueTooth: no points because some wheels play music directly from a USB stick). Horse trots away as the slam dunk specs winner.

For obvious reasons it's not as 'good' as a 2300W EUC, but having 1/3 the wattage isn't one of them.

I could rant for hours, I've been suppressing for decades.

Edited April 29, 2021 by Tawpie
just can't leave well enough alone

[mrelwood]

3 hours ago, Tawpie said:

A 750W horse

I simply love the way you think!  Anyway, I completely agree on all points.

Regarding wattage wars, I hope you haven’t dived in the worlds of guitar amps or hifi gear...

Edit: Ps. Thank goodness I’m not (a goth or) a female. I would never be able to decide whether 63% longer eyelashes are enough for me, or should I wait for the competitor that should get up to 69%.

Edited April 28, 2021 by mrelwood

[Tawpie]

1 hour ago, mrelwood said:

I hope you haven’t dived in the worlds of guitar amps or hifi gear...

not guitar amps, but did have my jaw dropped by people willing to pay 5000USD for hifi cables that had been baked so they were 'lower distortion'. Granted, they were baked at a very specific temperature for a secret-but-critical amount of time in a special hi-CO2 atmosphere so that shows you I'm just stupid. And I had a stereo salesperson promise me that there was a thousand dollar sonic difference between 0.001% THD and 0.0001%... coming through a $200 Altec Lansing 3-way floor speaker. I still bought the Yamaha, I liked the way it looked.

[mrelwood]

Yeah, one could have a full standup comedy show just reading through some of the “less scientific” Hifi catalogues.

Trying to circle back to the original topic... As you have noticed in your marketing experience, people who don’t know better need some numbers to compare. If the measure to be compared isn’t provided by the manufacturer/seller/salesperson, one will be made up by the public.

I once explained to someone in detail why the EUC motor “wattage” plays no practical role in perceived torque, ease of acceleration, or “zippyness”. I also explained which parameters do. The person thanked me for the explanation, and immediately continued asking if he should upgrade from a 2000W MSX to a 2500W MSP because he was intrigued by the “25% better acceleration”. 

The acceleration tests by YouTubers is another mess. If some Russian guy accelerates from 0 to 50km/h in 5s with an RS, the acceleration has obviously gotten much worse since the MSP that Kuji took to 50km/h in just 4s. 

 

After all these rants, descriptions and comparisons, the point of it all is that the answer to the original question is still “We don’t know”. And “Nobody will be able to tell you”. My guess is that it would probably do perfectly fine, but in the end the only way to know for sure is for you to try the hill with a V11 yourself, and afterwards check the graphs on temperature and power usage to be sure you weren’t near the limits.

Edited April 29, 2021 by mrelwood

[That Guy]

Hi Guys, after further research I think I will not go with the V11 at this stage. I think a safe bet for me will be the KS16X...  

[RagingGrandpa]

On 4/27/2021 at 2:16 PM, RagingGrandpa said:

Climbing slow (e.g. 10mph) is less stressful to the EUC.

Upon further consideration, that deserves some more caveats...

On 7/18/2017 at 10:01 AM, Chriull said:

almost double as fast going up the incline and still uses about the same motor current

As @Chriull pointed out a long time ago, for low speeds like comparing 5mph to 10mph, maintaining a constant speed on a constant grade requires roughly the same motor current (therefore: same torque) for various speeds. "Same current" then implies:

• Heat dissipation in the control board (e.g.: FETs) and motor cables would be no different when climbing faster.
• For a given total rise distance, the duration of the climb (and therefore the heating duration) is shorter with the higher speed, and so the peak temperatures reached would be cooler for the higher speed.

With the higher speed, a higher motor voltage will be delivered, and therefore a higher battery pack current (more heat dissipation in the battery pack) and higher system power... but the bottlenecks limiting the hillclimb are not regarding the battery current nor motor voltage, so the higher system power makes no difference with regard to overheating the controller. Controller output current is what matters here.

If speed becomes much faster than 10mph, aerodynamic drag causes additional torque and current to be required, and so the benefit will go away.
There is a sweet spot regarding the "coolest" speed to climb any given hill. Not too slow, not too fast.
 

Practical advice: if you have overheating problems climbing a paved hill at 5mph, don't be afraid to try 10mph: it is likely to result in a cooler board temperature once you reach the top.

(But, don't expect improvement going from 20mph to 25mph.)

 

Edited May 10, 2021 by RagingGrandpa

[Tawpie]

On 4/30/2021 at 12:43 AM, That Guy said:

Hi Guys, after further research I think I will not go with the V11 at this stage. I think a safe bet for me will be the KS16X...  

Not that being a 16X owner makes me biased, but “excellent choice”! I think you would have done fine with either wheel, but having learned on my 16, i have a very soft spot in my heart for it.

but more importantly, how is the adventure so far?

[That Guy]

Yeah, I've got my KS16X a couple of days ago and couldn't be happier. :-) It "eats hills for breakfast and wants more" (I think it was Marty Backe who said it about KS16X). No problem going up any paved hills whatsoever. One of the first things I did was riding up our steepest street and got a lot of "what the heck is that?!" and "look at that thing going up!" from the tourists and locals. One local lady came and said they should have added a budge for conquering the hill on a new device (they have budges of honor for a bikes, roller blades and something else up there)... :-) 

Sorry for talking about KS here in IM forum! I still think V11 looks very cool and I would be excited to have the next generation of Inmotion suspension wheel with (even) more power one day...