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KS14D performance on hills


Sobaka
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I have never used an EUC but I'm considering using one to get from home to train, train to work, work to train, and train to home. Essentially first and last mile transportation. Obviously I'm looking for something relatively portable so I can easily take it on the train and store it inconspicuously at work. I was leaning towards the KS14D. My only concern is how well it will handle hills. My last segment of the day, train to home, involves a steady hill climb over 2.1 miles at about a 5% grade (see below). Will the KS14D have significant slowdown (down from it's 18.6mph cruising) or overheating issues for a 160lb rider on a 2.1 mile stretch like this? If so, are there other EUC I should consider as alternatives? Thanks in advance for your advice--I'm excited to one day be a less novice member of this community!

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@Sobaka, welcome to the forum.

The very reason I got my KS-14C (which is chunkier than the 14D and not as powerful) was so it was easy to carry on transport and store at work. I found it fitted a small locker at work perfectly and was no trouble to carry on trains, subways or buses. 

Unfortunately London U.K. isn’t well known for its steep hills (the biggest hill within 50 miles is less than 700ft!)  so I’ll let someone whose had more ups and downs than I give a better answer.

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@Sobaka i iregularily drove up steeper inclines like this with the 9bot e+, having a bit more weight and having ~7km before on flat ground.

I don't know the ks14d personally, but i would not see any problem.

 

Edited by Chriull
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Hi.

It should (easily) do that, though if you want the top speed there, maybe a bigger diameter than 14 inches might be helpful in general. 18 mph is quite fast for a 14 incher. Though that increases the price.

@Marty Backe used a 14S (14D with bigger battery) for quite some strenuous offroad hill climbs, and it worked very well. Maybe he can chime in?

How far is the overall distance you'd ride in a day?

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15 minutes ago, meepmeepmayer said:

Hi.

It should (easily) do that, though if you want the top speed there, maybe a bigger diameter than 14 inches might be helpful in general. 18 mph is quite fast for a 14 incher. Though that increases the price.

@Marty Backe used a 14S (14D with bigger battery) for quite some strenuous offroad hill climbs, and it worked very well. Maybe he can chime in?

How far is the overall distance you'd ride in a day?

~8 miles. 2 miles downhill. 4 miles flat. Then 2 miles uphill. If I'm dropping down to 15mph on the incline, that's not a big deal. But if it's more like 8mph, that would be frustrating. I think the increased price and weight/size outweigh the benefits of a larger wheel unless the hill is going to pose significant issues on the 14D, and it sounds like it won't. It's also my first wheel, and a bit of an experiment for me--I may upgrade to something with better performance in a year or two once I feel more comfortable comparing the alternatives. It's hard to know what you don't know!

With regards to the 14S, I was under the impression that it would only perform better than the 14D in situations in which I drained the 14D's battery (or came close to exhausting it), given that the motors are the same and the difference is just in the batteries. So if I can do my daily commute with the 14D battery, would there be any advantage to the 14S?

Thanks to @meepmeepmayer, @Chriull, and @Keith for the advice!

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I'm not 100% sure about the 14D's range. It throttles the max speed starting at 50% battery (according to ewheels) but I don't think that will be a problem as you'll be over that all the time (I guess its range is quite above 16 miles). No real difference to the 14S for you, then. (And you can always charge at work anyway).

Edited by meepmeepmayer
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And also, if you start with a downhill run, you can't charge it to 100% at home or it will overcharge and stop you. But you can test and charge so it's virtually at 100% when you're down the hill. Doesn't mean anything else, just something to know.

Edited by meepmeepmayer
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1 minute ago, meepmeepmayer said:

And also, if you start with a downhill run, you can't charge it to 100% at home or it will overcharge and stop you. But you can test and charge so it's virtually at 100% when you're down the hill.

That's interesting. I presume there's an app that stops it charging automatically at a certain percentage? Or do I have pull the plug at the perfect time every evening, which would be a hassle? Or maybe I can charge at work to avoid the issue--this would also result in me tackling the hill on an almost-full charge.

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App can't do that. You can get a charge doctor (little gadget that goes between the charger and wheel), a timed outlet of some kind (plus one experiment to see how long to charge to x%), use the manual pull out method (careful:efee8319ab: - actually, since it takes some hours to charge, that wouldn't be too hard either), or just your charge-at-work idea (the simplest and best, I'd say).

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7 hours ago, Sobaka said:

I have never used an EUC but I'm considering using one to get from home to train, train to work, work to train, and train to home. Essentially first and last mile transportation. Obviously I'm looking for something relatively portable so I can easily take it on the train and store it inconspicuously at work. I was leaning towards the KS14D. My only concern is how well it will handle hills. My last segment of the day, train to home, involves a steady hill climb over 2.1 miles at about a 5% grade (see below). Will the KS14D have significant slowdown (down from it's 18.6mph cruising) or overheating issues for a 160lb rider on a 2.1 mile stretch like this? If so, are there other EUC I should consider as alternatives? Thanks in advance for your advice--I'm excited to one day be a less novice member of this community!

image.png.00985923dab07975b9b6032d8854c142.png

I have a 14d and have put a couple hundred miles on it . I weigh 180lbs. I only get around 7 miles of full performance riding and that’s at my local park (just a few small hills). If you want to ride fairly fast the whole way, you probably won’t be able to without getting a lot of tilt back. If it were me I would go for something that doesn’t throttle performance so early. It really starts around 60%, when you lean into it a little it drops to 50 or less and gives tilt back. Maybe check out the inmotion v8 (solo glide 3) . It has a little more battery and doesn’t limit you as much and it’s only 100 dlls more right now.

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The KS14D would certainly meet your very specific use case. I will note that you will not enjoy the riding experience that much if you intend on pushing it near 18-mph.

Although the KS14D can travel at 18/19-mph, that's its upper limit. The wheel is struggling, and you will find traveling at those speeds on the KS14D will not be a relaxing experience. I think the sweet spot for fast riding on this wheel is closer to 15-mph.

Other than that, the 14D is a powerful wheel that can easily handle your commute.

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Its more about the battery than the motor. The KS14S handles your requirements with its larger battery. It is "never" a good idea to full throttle up hills with "any" electric powered vehicle. It's not that many can't do it, it just puts extra stress on battery and possibly motor  unnecessarily. A long moderate climb is often more stressful than a short very steep climb.   If you are new to riding a EUC 8 mph will be terrifying at first.:D It will be awhile before you will wish to go 18 mph.;)

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3 hours ago, Jerome said:

It is "never" a good idea to full throttle up hills with "any" electric powered vehicle.

What he said. :thumbup:

3 hours ago, Jerome said:

If you are new to riding a EUC 8 mph will be terrifying at first

True. :blink:

3 hours ago, Jerome said:

It will be awhile before you will wish to go 18 mph

Like a few weeks... B)

My take:

I have a 14D and I ride it slowly (8 mph sidewalks/15 mph streets). Yes, more speed = more fun, but I am fat and the 14D has it's limits. I would be perfectly happy going slow uphill - but some people are only happy when pushing the limit at all times... If you are such a person, then take note that the 14D is an entry level and not a performance wheel. However, lower your expectations (and need-for-speed) and this is a suitable wheel for the conditions you have described so far... (Chances are you will want it to do more.) ;)

 

Edited by RayRay
Good for 'last-mile'
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On 4/17/2018 at 1:37 PM, Sobaka said:

... Will the KS14D have significant slowdown (down from it's 18.6mph cruising) ...

Sobaka, 18.6 mph is the TOP speed for the KS14D.  I would never refer to the top speed as "cruising speed".  I see ewheels.com is using that terminology (maybe just reprinting manufacturer info) and I think it's misleading.  Realize that this means if you try to go 18.6001 mph your face will meet pavement.

I ride a 16" wheel with a 20mph max speed and I have an alarm set at 15mph.  It's always a good idea to leave some headroom.

15 mph is pretty fast.  Unless you can run a 4 minute mile, it's a lot faster than you can run.  Imagine running as fast as you can into a brick wall.  There's nothing between you and the pavement if something goes wrong.

Also, as others have mentioned, a 14" wheel will not be as comfortable as a 16".  I don't think I'd want to step down from my 16 to travel 8 miles/day.

 

 

 

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16 minutes ago, JimB said:

Realize that this means if you try to go 18.6001 mph your face will meet pavement.

The KingSongs have the speed limit specifically so there's a safety margin. But your point is good, if you want to "cruise" at a wheel's "top speed", that generally means you should get a stronger wheel. For extra speed bursts, because you want some reserve power at cruising speed not just for safety, but also for performance and enjoyment.

I still think the 14D is a good option for OP if he wants a not-too-expensive start into EUCing (and it will certainly do the job), but if 18mph is indeed the desired cruising speed (one's first intuition of what is wanted is often the best) a stronger (and bigger diameter) wheel will be better. And 8 miles is indeed quite far, it will make you want to go fast automatically (at least if the route is suitable for speed).

Edited by meepmeepmayer
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9 hours ago, Jerome said:

Its more about the battery than the motor. The KS14S handles your requirements with its larger battery. It is "never" a good idea to full throttle up hills with "any" electric powered vehicle. It's not that many can't do it, it just puts extra stress on battery and possibly motor  unnecessarily. A long moderate climb is often more stressful than a short very steep climb. 

Full throttle at high speed is in most cases very near to or a real faceplant...

But going up a hill fast does not mean that there is more stress on the motor/battery/electronics than going up the hill slowly! Both cases need the exact same energy to go up. For simplicity asume "fast" is twice the speed of "slow". So going up "slow" takes some power p over some time t to go up (Energy needed slow = p x t ). Going up "fast" takes half the time and needs double the power. So Energy needed fast = 2 x p x t / 2 = Energy needed slow.

The power the electric motor produces is motor voltage x motor current. The motor voltage is proportional to speed. So for the fast case with twice the power p at double speed s (double motor voltage) the same current is needed as for the slow case with power p and speed s.

"Stress" for the motor/battery/wires and electronics is determined solely by the current.

So going up the hill twice as fast gives the same stress for just half the time as going up slow! So this means going up a hill twice as fast is half the stress for the wheel!

Only downside of this is that one comes nearer to faceplanting (high load with high speed -> faceplant)... ;( That's about one of the first things i learnt watching my brother (thanks again! ;) ) taking up speed before an incline (as one intuitively does with an bicycle) is a bad idea, as he imideately hit the ground on the incline as the wheel ran out of torque...

Also its hard to get up a hill fast - requires quite some leaning forward and the toetips tend to dig into the ground... ;(

With the losses (motor, battery, air drag) the reality is not as "easy"  (double the speed needs some more than the same current), but imho accurate enough for a first "sum up" - so for more details one can read the two topics: http://forum.electricunicycle.org/topic/7549-current-demand-versus-battery-voltage/ and http://forum.electricunicycle.org/topic/7855-anatomy-of-an-overlean/

 

4 hours ago, JimB said:

Sobaka, 18.6 mph is the TOP speed for the KS14D.  I would never refer to the top speed as "cruising speed".  I see ewheels.com is using that terminology (maybe just reprinting manufacturer info) and I think it's misleading.  Realize that this means if you try to go 18.6001 mph your face will meet pavement.

No. Absolutely not! at 18.6001 the wheel is tilting back or about to start to do so. (If this 18.6 mph is the max tilt-back speed set with the app).

Here in Europe the KS14D is sold with a max speed and presumably max tilt back speed of 30km/h which are 18,6411 mph - so we Europeans would faceplant all the time? ;) 

With the KS16B the top speed is advertised with 30 km/h and that was my safe cruising speed on flat terrain! (As long as the firmware did not restrict the max speed due to low batteries...)

I always (*) had my alarm and tiltback at 30 km/h, now with the KS16S at 35 km/h.

As one sees in the second link above there is still enough reserve! I'd assume that the figures are something like this too for the KS14D - also i don't have any data for this wheel... ;(

And as one also sees in this link the wheel can easily overlean("cut out") below this max speed too, if pushed hard enough.

4 hours ago, JimB said:

15 mph is pretty fast.  Unless you can run a 4 minute mile, it's a lot faster than you can run.  Imagine running as fast as you can into a brick wall.  There's nothing between you and the pavement if something goes wrong.

+1. Also if one could run this speed - overleans/"cut outs" often come by surprise and one can be happy if one has at least some reactions like lifting the hand to protect the face...

(*) after some familiarisation to the speed and the wheel coming from a 9bot e+

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On 4/17/2018 at 2:37 PM, Sobaka said:

I have never used an EUC but I'm considering using one to get from home to train, train to work, work to train, and train to home. Essentially first and last mile transportation. Obviously I'm looking for something relatively portable so I can easily take it on the train and store it inconspicuously at work. I was leaning towards the KS14D. My only concern is how well it will handle hills. My last segment of the day, train to home, involves a steady hill climb over 2.1 miles at about a 5% grade (see below). Will the KS14D have significant slowdown (down from it's 18.6mph cruising) or overheating issues for a 160lb rider on a 2.1 mile stretch like this? If so, are there other EUC I should consider as alternatives? Thanks in advance for your advice--I'm excited to one day be a less novice member of this community!

image.png.00985923dab07975b9b6032d8854c142.png

Avoid Gotway like the plague <Duck! Here come the Gotway fanboy hatered messages! ?>

Pretty much any mainstream manufacturers wheels will make that run. Even a Segway S1 could do that. It won’t be a challenge for any decent wheel. KingSong is my preferred brand <DUCK!>

The KS14 would be a great choice. Be sure and pad your wheel before you begin training. 

Here is my vid on that subject:

 

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Max speed does not mean max speed up 2.5 mile hill, or any hill for that matter.

You're going to want to go about 3/4 speed up a mild incline, and stop all acceleration for 2 seconds in regular intervals to de-load the battery and prevent the battery from emptying completely and shutting down.

If you want to avoid the need to stop accelerating periodically up a 2.5 mile incline, you're gonna need a bigger battery wheel.

14D is perfectly suitable for your needs, but not as suitable for your wants. And your wants will only increase after riding for two weeks.

 

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54 minutes ago, Scouts Honor said:

ou're going to want to go about 3/4 speed up a mild incline, and stop all acceleration for 2 seconds in regular intervals to de-load the battery and prevent the battery from emptying completely and shutting down.

???

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1 hour ago, meepmeepmayer said:

:confused1::confused1::confused1::confused1::confused1:

Ehm wut? Are you maybe drunk?:P This makes no sense. Never heard of anything like that.

You can't accelerate all the time anyways.

Going up with a constant speed (current) is better than slowing down and then accelerating again which needs a current spike each time.

One can argue whether a 14D with 2p battery can produce enough current for what OP wants, but... wut?

Acceleration was the wrong word. Foot on the gas, I suppose. On a long incline with a relatively small battery, unless that battery is full, the battery can drain down below 20% or 0% if under load for too long on an incline. Taking foot off the gas/whatever you want to call it and removing all load from the battery for a second or two can boost the battery levels back up again.

My view is probably distorted because my MCM3 only has a 340wh battery, and I'm 190 lbs.

When my battery is only 50%, I get low battery beeps and my battery bars go down from 2 to 0, on big hills, until I de-load the battery for a second or two and It goes back up to 2 battery bars again.

But if he's charging his wheel at work, or the hill is very mild in incline, maybe he'll be just fine and won't need to de-load the battery by coasting for a second or two periodically.

 

Edited by Scouts Honor
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14 minutes ago, Scouts Honor said:

Acceleration was the wrong word. Foot on the gas, I suppose. On a long incline with a relatively small battery, unless that battery is full, the battery can drain down below 20% or 0% if under load for too long on an incline. Taking foot off the gas/whatever you want to call it and removing all load from the battery for a second or two can boost the battery levels back up again.

thats a better description...

but actually the battery is not getting empty because of this normal occuring voltage drop. the "Charge" is still there.

 so as the voltage drop under draw can get up to 30% on a small battery, i would not advise to do such long draws on a very low battery.

but also: to prevent cutouts from voltage drops normally our BMS are designed not to cut the battery off/low voltage protection  on exact 0%

on a 67volt wheel 0% is about 52-53volt....the to low voltage protection of a KS BMS only would jump in at 48volt...aka -20% or so.

So as long as you hear to your warnings you are safe.

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1 hour ago, US69 said:

thats a better description...

but actually the battery is not getting empty because of this normal occuring voltage drop. the "Charge" is still there.

 so as the voltage drop under draw can get up to 30% on a small battery, i would not advise to do such long draws on a very low battery.

but also: to prevent cutouts from voltage drops normally our BMS are designed not to cut the battery off/low voltage protection  on exact 0%

on a 67volt wheel 0% is about 52-53volt....the to low voltage protection of a KS BMS only would jump in at 48volt...aka -20% or so.

So as long as you hear to your warnings you are safe.

Is it true that the upcoming Z wheels from Ninebot are all low voltage wheels? Could that negatively affect their hill performance? 

Edited by Scouts Honor
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