..........Returning from a 6 mile ride I could feel some slight warmth in the motor, bit concerning on such a short ride and not the steepest hilss I tackle. Never felt any warmth in the big Ezee........

I find what you say above interesting. I changed my front motor from a MXUS to a AKM 100 and found the same. But I think they are two different designs of motor. The mxus has its copper stator in the center whereas the akm is described as an 'Inner Rotor Motor' and has the magnets in the center and the stator on the outside. I suspect (and hope) that this probably makes the AKM better at shedding heat. In this way, I am thinking (and hoping) that the AKM in being warm on the outside is perhaps a positive thing as the heat is escaping.

The mxus by the way gets very hot on hills but can mainly be felt on the axle where the cable enters. In my case, the right hand fork use to get very hot as well.

Yeh, checked that and it is as you say. I think the rather underwhelming performance is a mixture of wrong wheel size, 17A maximum current setting and running it at 36v, not to mention being so used (11 years) to the full power kick from the very torquey Ezee.

I'll take it out again tomorrow and see how it is now it's been fettled.

My Q128 was pretty powerful at 14A. i was happy at that for ten years, then I tried 22a, which is too much. That's at 48v.

 

The point I was making is that a simple tap of the throttle gives you immediate maximum power when you want it. the rest of the time, you can use whatever power is comfortable. The throttle saves you from having to keep pushing buttons, and it makes the LCD4 much more viable.

If you set the throttle like I said with P4 =1 and C4=3, you can use it to give instant max power when you need to pull away quickly, dash round a roundabout, through a busy junction or anything like that. That's one of the best features of the KT controllers.

 

I can concur. I just had to try my recently acquired 48v. battery (bought for my hybrid fitted with a Yosepower 250w. cassette motor) on my Yosepower 350w. freewheel motored "winter bike".

Flippin' awesome at 15amps - no need for anything higher from the 20A KT controller.

By far the best feature of these controllers (for me) is the P4=1, C4=3 legal throttle setting.

Works without pedalling up to 6km/h for gentle start assistance, then full throttle above that speed whilst pedalling . Stop pedalling and throttle won't kick in again until speed is below 6km/h. or you start pedalling again.

As saneagle points out this means you don't have to keep pressing buttons to change PAS levels. I stay in PAS 1 most of the time and just "boost" with the throttle when needed. It almost eliminates the need for any gears, particularly when I'm feeling lazy and just "ghost pedal".

the akm is described as an 'Inner Rotor Motor' and has the magnets in the center and the stator on the outside. I suspect (and hope) that this probably makes the AKM better at shedding heat.

That's interesting Sturmey, I hope you're right. It's puzzling though because, if the windings are on the outside, wouldn't this need slip rings, or somesuch, and therefore brushes?

The point I was making is that a simple tap of the throttle gives you immediate maximum power when you want it. the rest of the time, you can use whatever power is comfortable. The throttle saves you from having to keep pushing buttons, and it makes the LCD4 much more viable.

I see what you're saying, I'll try that when I get out today. It may mean I have to reconfigure the handlebars to make the throttle easier to reach.

I'll also see if the increase to 20A gives me the hill climbing torque I need. This is my main concern. The test hill I'm using, to get the feel of this new system, is around a mile and a quarter long of moderate to hard climbing. Haven't tried any of the lung/leg busters yet and there are many of them round here.

Back to your wheel build: why a '1 cross' pattern on such a large wheel with powerful motor? Surely a '2 cross' with its larger spoke angle would have significantly lower spoke loads under power?

I reduced the current to 18A from default 22A on my 48V full sus bike with Bafang G020 rear hub motor. It seems plenty powerful enough on the numerous 20-25% max gradient hills round here with my 105kg weight with some pedalling effort.

Back to your wheel build: why a '1 cross' pattern on such a large wheel with powerful motor? Surely a '2 cross' with its larger spoke angle would have significantly lower spoke loads under power?

I went as recommended on the Grin site, their recommendation is to keep to one cross. In retrospect maybe they're more used to 26 inch wheels and larger motors.

Thanks Peter, i am starting to think that 48v is going to have to be the solution. I'll see after todays ride out.

That's interesting Sturmey, I hope you're right. It's puzzling though because, if the windings are on the outside, wouldn't this need slip rings, or somesuch, and therefore brushes?

Aikema in their catalog below divide their hub motors into two categories, inner rotor and outer rotor. The inner rotor type does not have a continuous axle but two shorter axles with the body of the motor forming part of the axle as shown in photo below. This allows them to fit an inner rotor motor and also a much greater gear reduction as far as I know.

I have never dismantled one.

AIKEMA Catalog 2025 V2.0.pdf

Just been to the next village to get my artisan baked sourdough - I know !

Any way system set to 20A seems a lot better. Giving me around 320w on 4 and 650ish on 5. Not sure how saggy this is going to make the batteries but they're on charge now ready for a longer run this afternoon.

Pas is very quick to kick in (V12). Throttle not so quick. There seems to be a smoothing algorythm or something, i.e. using the throttle from level 3 (around 250/280w) it takes around 15 seconds to ramp up seeming to stop short of full wattage. Cut off looks to be exactly 16.5mph, slightly hard to tell 'cos it's so smooth.

Think there's a psychological thing going on here, this motor is soooo quiet I'm working harder because I think it's not working.

Just been on a 15 mile ride, think I'm starting to the feel of it. The advice of using the throttle on short ramps/climbs is certainly useful. I'm going to have to re-arrange the handle bars to make it more accesable.

Coming back from the local town on what passes for a main drag around here, it was easy to maintain 16mph on 3 and I could feel the slight drag and push of the motor coming in and out. I can now see why people new to eapc's think there's something amiss - it does feel a bit strange.

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.

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?

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?

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.

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?

........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 .

https://www.pedelecs.co.uk/forum/threads/kt-controller-strange-behaviour.48804/#post-746420

Edited June 25, 2025Jun 25 by Sturmey

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.

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.

Edited June 26, 2025Jun 26 by Benjahmin

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.

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.

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.

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.

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.

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.

Are you sure that you don't have C4=4.? It should be C4=3. Mine goes instantly to full power.

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.

I was thinking of using a 260 rpm akm-128cst for my gravel bike. I was thinking of running one marked as 201 rpm 36v at 48v but I just thought, could also run one marked as 328 rpm 48v at 36v