My ebike has the KT-LCD5 controller fitted, if l change the controller for one off ebay will l

be able to adjust the maximum assist speed?

 

Not that it will go that much faster, it's a single speed so l guess 18mph will be about it.

 

But, can anyone tell me is the restriction in the display/control unit or elsewhere?

 

You can set the max speed to anything you want on the one that came with the bike, but the bike still only does 15mph.

 

Also, if the restriction is in the controller

ls this a genuine KT controller?

 

https://www.ebay.co.uk/itm/353979811739?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=PzT9OwbRSnK&sssrc=2349624&ssuid=Cj4IjO6GTG6&var=&widget_ver=artemis&media=COPY

Does nobody know the answer to this? l thought these controllers were widespread and popular.

 

l know that on the more expensive mid-drive MTB's the display is just that, it doesn't contain the operating software.

 

But l wondered if these hub-drive folding ebikes were the same, or if the software was in the controller/display

The Kt lcd's don't restricted the speed as such, it is the motor winding that's likely holding you back for the small wheels.

So you are saying it could well be restricted to around 16mph on account of the motor itself being designed to do that speed under full power?

 

And the reason you can increase the "max speed" on the display to (say) 20mph, and it doesn't make any difference, is because the motor physically won't go any faster

 

That does make a lot of sense.

So you are saying it could well be restricted to around 16mph on account of the motor itself being designed to do that speed under full power?

 

And the reason you can increase the "max speed" on the display to (say) 20mph, and it doesn't make any difference, is because the motor physically won't go any faster

 

That does make a lot of sense.

 

Yes, smaller wheels depend on a faster motor winding to go faster so it boils down to the motor used.

My dsplay allows me to set 49.9 but it is pontless doing so.

The last KT controller I had, had looped wires which could be plugged or unplugged, one was for cruise function, one was for self learn and the other was a speed/power restriction wire. These wires you will notice will basically come out of the controller and go back in the controller, I found the speed difference when I unplugged one of the 3 which gave about a 4mph increase.

I think white is usually self learn which leaves you with the other two I just unplugged both so I can't 100% tell you which belonged to the speed restriction and which to the cruise function.

 

Unplugged = faster/unrestricted

Plugged in = slower/restricted

Never had self learn wires on any of the kT's I have bought or any I have looked at.

Cruise and speed restriction yes , but not SL.

So ultimately [mention=35530]lightning[/mention] unplug all your looped connectors on your new controller and you'll get the fastest speed with the setup you have.

Thank you l will have a look later.

 

l managed to turn on the cruise function in the setup menu, although you need a manual to go through it all.

 

l also found an option to turn on the throttle, but l didn't bother with that.

cruise function

Once "cruise function" is enabled in the C7 parameters, all that should be required, and I think it applies to LCD5, but LCD3 once at PAS/throttle desired speed when riding, hold down the "down" function arrow on the display(LCD5) and it should lock the speed you are traveling at until you engage the PAS, brake(sensor) or throttle.

Hi there yes it does, but it won't allow over 15mph, if you pedal faster and set it, the speed drops to 15mph and it sits at that speed

I'm sure if you use throttle fully twisted for either 6 or 8 seconds it should automatically activate cruise function, leaving ho of the throttle and then a slight twist will deactivate it.

The wheel size of my bike is 16"

 

l've done some experiments and if the wheel

size is set (on the controller) to 16" the motor will assist to an indicated 15.5mph (actual speed on my GPS around 14mph)

 

If you set the wheel size to 14" the motor will still drive the bike to an indicated 15.5mph (actual speed around 17mph) but only when the battery is full. Once the battery is partially depleted it will only manage around 14.8mph on the bike's speedometer

 

lf you set the wheel size to 12" the motor won't drive the bike past an indicated 13.8mph (actual speed around 17mph)

 

So it seems l've reached the maximum rpm of the motor, it's obviously designed to max out at around 16mph

Edited June 20, 20223 yr by lightning

l've reached the maximum rpm of the motor

Sounds about right, if you are running 36v then stepping up to 48v would give 30% more rpm however you would need a new battery and controller, unless the controller is marked 36/48. I have both 36 and 48v and the same battery mount for quick local errands I use 36 and for pleasure rides the 48v the advantage of a dual voltage controller is I don't have to swap out the controller each battery change, although with 36v I, like you are limited to lower rmp.

ln the controller setup l have this setting for the "maximum current adjustment"

 

There are ten settings and on the Mirider it's set at 9 which is "maximum current value divided by 1.1"

Setting 10 is "maximum current value"

 

Will there be any difference if l set it to 10?

 

No, current doesn't increase speed, you need voltage & more of it.

If your controller is dual voltage a 3s battery in series will give a boost of speed.

So there's no point in turning it up to 10 then, would it not increase the torque?

 

More speed isn't really worthwhile because the single gear spins out at about 18mph anyway, it's unsurprisingly designed to do 15mph

One will get a small torque increase but doubt one will notice it that much, it will equate to approx. 9% increase. But that isn't what you asked about.

One seem fixated on the speed issue, it is small wheels so except the legal speed or simply pedal harder or increase gearing to over come the cut off speed.

Yeah l was just wanting to see if l could get a bit more out of it, but l knew nothing of hub motor technology and maximum RPM's etc so it's been a learning curve.

 

Thank you for all the advice, this is a great forum.

Ok we are all up for learning.

Even mid drives suffer much the same with the speed limit unless they are dongled , one has to use gearing to to go beyond the cut off. With hubs one has to choose the given rpm for the speed one wishes to cycle at but then hill climbing ability is affected unless one also increase the current by quite a bit or uses a higher voltage, it depends how far one wants to go out side of the window.

Problem with voltage increase is the more cells required and heavier batteries, though one can offset that a little with 21700 cells and 10/15a rated ones. one could have a theorectical 15ah 30a/45a rated battery but for longevity 15/18 would be the max current draw, alternately one could opt for 12.5ah and a 30a max current draw.

As with all batteries it is the siting of either a hard case on a frame/rack or softcase type in a pannier or frame bag.

A good example of a very good hub which I use for my Roadrat and towing a laden trailer (up to 90kg) is the Bafang G370, it has a fairly high two step gear ratio and is 36v 201rpm rated so about 16/16.5mph at 700c.

I run it at both 36 & 44v but not for the speed but the unpowered ability, I have intentionally set the cut off low at 13.2mph just to get me going and then without too much effort rides nicely to 20 mph unde rmy own power (without a trailer). For towing slow I'm happy with for stability esp some of my precious cargo.

My YOSE is circa 220rpm based on the sales pitch of 36v with that extra 30% on 48v I get 280ish rpm and better mph plus no issues up hills however I keep my amp to 14 or 15 if I swap out a controller, but my 14a has served me well & if I was to put my 17a on I would reduce that to 15/14. Now when that dies I'll use my new mxus but that rpm is 270 [mention=22943]36v[/mention] so circa 330rpm on 48v but keeping my amps low should prevent/minimise overheating when up hills, but gain a mph or two. Any problems on 48v and I stick to 36v or amp reduce to 12/13