Torque vs Cadence Flat SW Florida

[m@Robertson]

Sounds like true cadence (crank RPM) is being taken into account, not just the presence or absence of crank rotation.

While KT documents nothing beyond the existence of the settings and a very vague Chinglish description, I agree that it is likely that the cadence rate in conjunction with speed is worked in as part of an algorithm (its definitely not just speed, either). It is absolutely not the dreaded 'on/off switch' you hear so much about with lesser controllers found on many DTC ebikes. My very first ebike was a Sondors in 2017 and since they used KTs factory stock, I thought thats how they all worked for the first few years.

Does this KT system offer on-the-fly assist levels (apart from the "slow start" adjustment)? If so, what exactly do they control?

Yes. They are a 5-stage output selector. There's no documentation on the percentage of potential power delivered. The C5 setting @PCeBiker showed above determines how much output the motor delivers for either throttle or PAS. So C5 is a way to throttle back the overall amp output of the controller and de-fang the Bafang hub (I will say three hail marys as penance for that). Lets say you have a 35a controller, if you set C5=10, when you hit the throttle or use PAS, your power curve's peak is not trimmed down. If instead you set C5=05, the your peak 35a controller is now a peak 26.3a controller (35a / 1.33). The power curve to get to that 26.3a peak is unchanged. HOWEVER if instead you set C5=00 then your peak amperage stays at 35a, and instead the throttle curve to get up to that 35a peak is flattened out, so you get to your 35a more slowly (i.e. you start out more slowly). 01 is like 00 but a little less flat, and 02 is the mildest effect, being a bit less flat than 01. 00, 01, and 02 versus 03 thru 10 are two fundamentally different effects on power delivery in the same setting.

C5=10 on my twin hub awd bike makes for a bike that can do a rear wheel chirp and a front wheel 1/8 turn burnout before it catches with a slick front tread. C5=00 gives me a safe start from a stop, but within say two seconds its pouring on that power full blast.

All KT settings across all of their models appear to be the same. I use the LCD-3, the LCD-4 (my favorite) and LCD-8H. There are actually a couple of minor changes but they would not be noticed unless someone pointed them out. If you want to lose the Chinglish and be able to actually read the thing, Dillenger's LCD-3 manual was translated by someone who knew English. But it uses the old form and lists the C5 slow start settings as 'undefined' - which is baloney. The manuals just didn't admit to what they were until recent years.

Manuals

dillengerelectricbikes.com

 

[m@Robertson]

C1=0, 1, or 2 allow for slow start power levels.

I think you mean C5 = 0, 1 or 2. C1 defines how the PAS sensor works. Disc on the right side with magnet count, or use the reverse-direction settings if you need to put the magnet disc on the left side (which is what I do with my 2wd bikes with a BBSHD powering the back wheel) or use the KT V12 self-contained rotating sensor (don't do that if you can avoid it... they suck)

I might try C1=0 to see what happens. I don't have to use full power, at least not all the time.

You will get a slower start that gives you access to the full amps of your controller. This is what I use. I found that for 35a controllers I was stressing the dropouts of both the front fork and rear on the frame even with two torque arms on each. The creaking didn't start happening until a few months down the road. With twin hubs at C5=0 working as a team the bike is still faster off the line than just about anything else out there.

I think I tried it once, but it didn't work because I don't have my cadence sensor hooked up?

C5 affects both throttle and PAS power delivery. "Maximum operating current" as written in the manual. This is why you use the manual written in proper English

 

[PCeBiker]

I think you mean C5 = 0, 1 or 2. C1 defines how the PAS sensor works.

I just fixed that in my post.

I'm going to give C5=0 another try.
I just tried it with the wheel in the air and got it spinning.
I did notice that the wheel didn't spin when my throttle gear was set to zero.

I wonder if that's what happened the only other time I tried C5=0

 

[PCeBiker]

All KT settings across all of their models appear to be the same.
There are actually a couple of minor changes but they would not be noticed unless someone pointed them out. If you want to lose the Chinglish,..

The Dillenger's LCD-3 manual doesn't cover the additional C4=4 adjustment available on the LCD-8H, so I have to use the Chinglish version.

When C4 = 4 is confirmed, the "percentage value of the first gear speed accounts for its full speed" of the power assist gear flashes, press (UP) button or (DOWN) button for short to make selection, and the default value is 50%. The percentage values of other gears divide automatically in equal.

I think that I've got it figured out, so I'm going to keep the C4=4 at 20% and set C5=00,..

I want to see what first throttle gear feels like.
I think that I'll get 20% of full power now instead of 20% of half power when I had C5=3

I just noticed too, that I had the power set to C5=4 so ⅔ not ½ power.
I'm going to try the "Three Level Slow Start" and see what that feels like combined with different throttle gears.


I didn't want to use the slow start because it still takes the power up to full, and I wanted to cut my power in half to help extend my battery range and not stress or overheat anything.
But, I find myself CONSTANTLY checking my Watt meter when I'm riding, so I will be aware when I'm throwing over 1300 Watts at my 750 Watt motor.

 

[PCeBiker]

,.. It is absolutely not the dreaded 'on/off switch' you hear so much about with lesser controllers found on many DTC ebikes.

My DTC Et.Cycle T1000 came with that dreadful on/off switch.

You can see the throttle and my first attempt at a throttle lock/cruise control,..

Electrical tape and a piece of popsicle stick was just the right thickness to prop my throttle open to about half.

It's much like @PedalUma 's story about the guy that used a zip tie to hold his throttle on, never to be heard from again, but I've always made it back alive to talk about it.

I've had many throttle lock/cruise control versions since then, including the built in Cruise Control of the KT controller.

This is the version that I came up with that I like the best,..

It's the most user friendly and ergonomic for me to operate, and you can't turn it on accidentally.

,.. with lesser controllers found on many DTC ebikes.

The Das-Kit Controller on my ET 1000 is actually an Awesome controller.

Too bad I couldn't use the KT-LCD8H to control it.

It's probably built in China but it's German engineered.
It's fully potted and completely waterproof. It has a very well built circuit board, and a cast aluminum box/heat sink, that's as tough as nails.

It's mounted in front of the bottom bracket where you can bounce it off rocks and curbs and not damage it.

All the KT stuff is junk by comparison (except the programming of course).

It's not just the cadence sensor that you mentioned, the throttles and display brackets are crap too.

My display bracket snapped when I tried to unbolt it. Sure, it's only seven bucks for a new one, but you better buy half a dozen of them cuz you're going to need them.

Same goes for throttles, cadence sensors, and of course the controller itself.

It says it's waterproof but that's a load of crap.
It's got a three sided cover with a screw on bottom and two flimsy end covers with useless "gaskets" stuck on.
They have been know to fill up with water and blow up, so you better order at least two of them, cuz waiting a month for a replacement to arrive from China would suck.

I put my controller is a plastic "waterproof" box, and hosed the circuit board down GOOD with ACF-50 first.

I also drilled a pinhole in the plastic box to let any water drain out if my ebike ever sees rain.

All that "waterproof" really means is that any water that finds its way into the box or controller is sealed in there.

The ACF costs me almost as much as the controller.

 

[Jeremy McCreary]

I know @Jeremy McCreary knows how to use gear calculators, and used it to choose new "sprockets" for his ebike.
Maybe he can help with some rough calculations to figure out what chain ring you may need, and which ones will fit your ebike?

I outlined my largely empirical approach to gearing here. Here's a shorter version:

1. Memorize just your top and bottom gears in gear-inches using an online gear calculator or spreadsheet.*
2. With these figures in mind, ride your target terrain, especially the big climbs and descents. Take note of how well these top and bottom gear-inches actually meet your speed and cadence needs.
3. If you find that you need a higher top gear (like the OP), ask yourself if you could live with a higher bottom gear. If so, a larger chainring might be all you need. If not, you'll likely have to change the cassette as well.
4. Guess the top and bottom gear-inches to try next based on your testing and get as close as you can with available/affordable parts. Rely on the cassette manufacturers to space the gears in between.
5. Test again with the new top and bottom gear-inches in mind.
5. Repeat till your top and bottom gears are dialed in for you and your terrain. Took me 3 tries but totally worth it.

Let your LBS mechanic help you with all this. Ask if you can go to a larger number of cassette cogs at reasonable cost. My LBS increased mine from the stock 9 to 10 with spectacular results, but the chain, derailleur, and shifter had to be changed as well. Around $400 with labor, but I ended up with much better components and vastly improved shifting and reliability.

* By working in gear-inches, your optimized results will apply to bikes with any wheel diameter.

 

[m@Robertson]

The Dillenger's LCD-3 manual doesn't cover the additional C4=4 adjustment available on the LCD-8H, so I have to use the Chinglish version.

Hah that is EXACTLY the oddball difference I was thinking about when I made my original statement. The feature you note is not even found on all LCD-8H's. Mine doesn't have that. Its identical in its features to the LCD-3 and LCD-4. If you look at the Area 13 tutorial on changing the LCD-3 and LCD8H settings I don't believe its on that LCD-8H either.

Also the LCD-4 has a walking throttle speed adjustment that doesn't seem to actually do anything.

 

[m@Robertson]

My DTC Et.Cycle T1000 came with that dreadful on/off switch.


You can see the throttle and my first attempt at a throttle lock/cruise control,..

No what I was talking about was how many controllers treat PAS as if its just an on or off switch with nothing in between, and no awareness of how fast the crankarms are turning. Its just an on switch that delivers 100% motor power or it switches off and delivers 0%

My display bracket snapped when I tried to unbolt it. Sure, it's only seven bucks for a new one, but you better buy half a dozen of them cuz you're going to need them.

I think I bought three when I first saw them a few years ago. I've never used them and dammit I don't know where the box is, although I did come across it like a year ago in storage.

Same goes for throttles, cadence sensors, and of course the controller itself.

I have throttles socked away like two or three deep. The new Bafang ones with the clamshell mount are worth their weight in gold,. Plus the KT controllers I have use black HIGO plugs which are rare, so I keep a couple extras on hand in case of a crash taking one out (which has happened).

Today while changing out a display I found a new thing to screw up: My throttle connection snapped on the wiring harness side. Since I use Magura brakes I use the California Ebike special harnesses. Luckily I have one extra but that still means I need to buy one more so I have another in reserve.

 

[PCeBiker]

No what I was talking about was how many controllers treat PAS as if its just an on or off switch with nothing in between, and no awareness of how fast the crankarms are turning. Its just an on switch that delivers 100% motor power or it switches off and delivers 0%

Yes, it happened in PAS mode as well.
The slowest PAS mode speed was around 18 kph which isn't slow enough.
There was a lag after you stopped pedaling and a lag when you started pedaling and it would turn back on at full power.
The kick wasn't as noticeable at higher speed but you could still feel it.

 

[PCeBiker]

,..: My throttle connection snapped on the wiring harness side.

Keep in mind that if you lose your ground connection to your throttle, the throttle input to the controller goes to full power.

I tested for that when I was breadboarding my potentiometer to use as a cruise control.

The KT controller has a throttle input between ~0.8v and ~4.2v.
Anything below 0.8v or above 4.2v will give you a throttle fault.
With most Bafang throttles, when the ground is disconnected, the voltage goes up but not over 4.2v like it should, so you get full throttle.

I've got a spare throttle in my tool bag.
I don't have my PAS sensor connected anymore, so if my throttle fails, I have no power.