Help! My next project

[Benjahmin]

I've moved the throttle to the right which means the up/down buttons are now closer to the left grip. I can reach both easier now.
25 miler today incorporating some of the more severe climbs. System is very smooth and quiet. Going up and down the power levels a lot, it's the nature of the roads around here. Able to get 16mph even in level 1 when on a good road surface and no wind. Mostly using 3 & 4.
Still suffering from the lack of torque on hills but I know that will be sorted by going 48v. Looks like I've been really cosseted by the big diameter Ezee motor for the last 11 years.

 

[saneagle]

I've moved the throttle to the right which means the up/down buttons are now closer to the left grip. I can reach both easier now.
25 miler today incorporating some of the more severe climbs. System is very smooth and quiet. Going up and down the power levels a lot, it's the nature of the roads around here. Able to get 16mph even in level 1 when on a good road surface and no wind. Mostly using 3 & 4.
Still suffering from the lack of torque on hills but I know that will be sorted by going 48v. Looks like I've been really cosseted by the big diameter Ezee motor for the last 11 years.

The Q128 is a brute if you give it the power. Can you remind us which speed variant you have?

 

[Benjahmin]

That I can't remember, there was so much back and forth when I bought it. I originally bought it for a 26" wheeled recumbent.
I do know it's 48v currently being run at 36v max 20A,
Here's the number from it if it means anything:

AKM23032901002
BBA4816B

When changing from, say, level 2 up to 4, the power raise takes time to increase. Similarly after a down hill run, so no power, it takes time to ramp up from zero to set level. Is there a setting that will make this a bit faster?

 

[Sparksandbangs]

Unless there are other variants that aren't available now the 128 only seems to come in 201rpm or 328. A 48V 201 running at 36V would be slow.

 

[Cadence]

Have you tried setting C14 to 3? In the Chinglish instructions this is 'assist strength of intelligent pedal motor". My KT's came set on 2 (of 3 levels).
I tried setting 1 out of curiosity and it gives a slow ramp-up which I guess would be useful in being more gentle on nylon gears when using high amps. I didn't try setting 3 but would expect a more immediate response from the PAS sensor. Worth a try?

 

[Sturmey]

........Similarly after a down hill run, so no power, it takes time to ramp up from zero to set level. Is there a setting that will make this a bit faster?

There was a discussion lately where a recently fitted AKM had similar problems .

KT Controller - Strange Behaviour

I realise that there might not be an answer to this. I have a downhill on my regular journey. The bike is geared so I can get it up to 27/28mph under my own steam, no assistance 15.5mph cut out. When I get up the next hill and the bike drops below 15.5mph there is no assistance. Legal throttle...

www.pedelecs.co.uk

 

[harrys]

I've had a 48V 201rpm Q128 sitting around for several years. I finally installed it into a stepthru for my wife this month. I spoked it into a 26" wheel, 1X cross, all elbpws out. I've read that 2X on a 130mm hub leads to sharper spoke angles.

 

[Benjahmin]

Just found my original thread when I bought the kit. After much back and forth I ended up with a 48v 328rpm, so running it at 36v should be giving me 260 rpm. However speed is not the issue, it's hill climbing torque. I'm beggining to think that I may have stuffed myself here. If I go to running it at 48v (so giving more torque) the motor will be well below it's rpm when running at 15/16 mph - so making it inefficient? This would be worse, wouldn't it, at hill climbing speeds?
Seems to be drawing 680-720w in 5, 350ish in 4, 250 something in 3. There is never a steady reading, it jumps around a lot.
So what I'm seeing is, let's say I'm in 3, Icome to a steep ramp and press the throttle. There is a slow ramp up to higher wattage which never gets to the 700ish level. Seems to top out around 650.
Similarly after a long descent, high speed so no power, as the speed falls below the cut off there is a delayed/slow ramping up to set power. I think this what the thread that Sturmey linke to was trying to get at.

Have you tried setting C14 to 3? In the Chinglish instructions this is 'assist strength of intelligent pedal motor". My KT's came set on 2 (of 3 levels).
I tried setting 1 out of curiosity and it gives a slow ramp-up which I guess would be useful in being more gentle on nylon gears when using high amps. I didn't try setting 3 but would expect a more immediate response from the PAS sensor. Worth a try?

Thanks Cadence I'll try that.

Another curio. When riding above cutoff speed I see the watts reading jumping around from zero to 10-12 watts. Only stays at zero when not pedalling or brake cutoff is used. Not an issue just odd.

 

[Sparksandbangs]

It's mine that has the weird behaviour. It happens at all speeds above cut off point but it's random. I try to replicate it and I can't and all of a sudden it happens and catches me by surprise. It's not a slow ramp. There is no power showing as I drop below set point and then suddenly after a delay it kicks in.

I used to have a Bafang motor and saw the 10w that you noticed after cut off. Reading previous threads on here it is there to give just enough power to keep the clutch engaged. Since changing to an AKM motor I no longer get this.

 

[Sturmey]

I am inclined to think that good performing motors with KT controllers dont like being hobbled/restricted to 25 Km/hr. The motor is just hitting its peak power band when its suddenly cut off. But the impression I get with some kits is that it does seem to work ok with lazy legs and a fairly standard low rpm 36 v setup as the power seems to be naturally getting weak as it approaches 25 Km/hr anyway.

 

[saneagle]

Just found my original thread when I bought the kit. After much back and forth I ended up with a 48v 328rpm, so running it at 36v should be giving me 260 rpm. However speed is not the issue, it's hill climbing torque. I'm beggining to think that I may have stuffed myself here. If I go to running it at 48v (so giving more torque) the motor will be well below it's rpm when running at 15/16 mph - so making it inefficient? This would be worse, wouldn't it, at hill climbing speeds?
Seems to be drawing 680-720w in 5, 350ish in 4, 250 something in 3. There is never a steady reading, it jumps around a lot.
So what I'm seeing is, let's say I'm in 3, Icome to a steep ramp and press the throttle. There is a slow ramp up to higher wattage which never gets to the 700ish level. Seems to top out around 650.
Similarly after a long descent, high speed so no power, as the speed falls below the cut off there is a delayed/slow ramping up to set power. I think this what the thread that Sturmey linke to was trying to get at.

Thanks Cadence I'll try that.

Another curio. When riding above cutoff speed I see the watts reading jumping around from zero to 10-12 watts. Only stays at zero when not pedalling or brake cutoff is used. Not an issue just odd.

Mine is a 260 rpm 36v, which is the same as 328 rpm 48v. It works perfectly for the steep hills around here. They're maybe not as long as yours, but some are very steep, like up Ironbridge Gorge, which is a climb of about 350 metres.

 

[Benjahmin]

Good to know, I will persevere.
Although I've been a utility and leisure cyclist since I first rode a bike (roundabout 5 or 6 I think), I have never been a strong cyclist. Always suffered from tired legs and would regularly get left behind when out causing mischief with my mates. So there's a me element here. Maybe you got issued a better set of legs !
I do see forum members talking about getting up this or that hill at 15mph without pedalling, I can't see that happening. So I'm OK with a certain leg dependancy and certainly being electric is the only way I am cycling around here at all.

 

[Benjahmin]

I've changed C14 to 3. I think it's made an improvement, hard to tell. Here's what I saw:
Trundling along on 2, I came to a steep bit. Pressed the throttle. Wattage increased rapidly to 380-400 ( which is level 4) then slowly up to 680ish. So tried an experiment. From level 1 I tried the throttle, went quickly to 250ish (level 3) then slowly up to 680. From level 3 it will go fairly smoothly up to 680.
It would seem that it's configured to not apply surges of power to the motor.

On the main road run into the local town there is a V shaped bottom. So, around half a mile steep down, 35mph. Steep on the other side around 1:6. Set assist level to 5 at the top of the descent 'cos I knew what was coming. As I hit the rise started to pedal at 30mph waiting for assist to kick in. It didn't kick in until around 11 mph with a slow ramp up to 680w. The result was I was down to about 5mph by the time the assist was useful.
That's a pig because there were two more such Vee's on the way home. However these were far more..........rustic (through woodland with a mossy road surface), with a steeper descent and climb out. The delay here had me down to 28 ring and 2nd gear just to keep moving. Nearly stalled.
The power is there - eventually and the sound of the motor tells me it really doesn't like these slow high power climbs. Trying to get back up to 8mph on a steep climb is challenging.