Anyone replaced the controller of a 700 or Cafe Cruiser?

[Ridersofthenorm]

Alright, I've been working on this for several days now and literally just finished it a few moments ago:

Can finally clean this up and go for a ride

https://imgur.com/tW5aEGz

I hid all of the wires behind the chainring. Tried to make the small bag look as natural as possible. Took multiple extension cables for every wire, lots of soldering, lots of routing troubles, plenty of cursing, and staring at the ceiling but eventually I got it done lol.

PS: After a long exchange with Ride1up, they refunded me $100 and have updated the Cafe Cruiser's sales page to say 18A.

 

[Ridersofthenorm]

I seem to have ran into another issue. After installing the 25A KT controller and testing it out, I am peaking at 1100W. The specs for the battery say 30A continuous and 45A peak.

Using throttle uphill I'm getting 15mph while sitting at around 900W instead of the controller ramping up. Downhill I'm somehow slower than I was with the JN controller. Downhill tops out at 24mph whereas on the 20A JN controller I would get 28mph downhill.

I'm truly at a loss. I followed the Bolton ebikes guide to set it up and played around with P1 & P2. Same results. Google really isn't helping me either.

My previous Ebike with a KT controller would push me even if I was at top speed downhill. This one goes very weak in the same scenario.

 

[AHicks]

Explain "peaking at 1100W" vs. "Using throttle uphill I'm getting 15mph while sitting at around 900W" please?

It SHOULD be peaking, whatever you're going to get, while pulling wide open throttle.

What kind of connectors and size of wire between the battery and controller? The controller can't pass any more than it's getting.....

Battery voltage sag from a partially charged battery?

C-5 setting?

 

[Ridersofthenorm]

Explain "peaking at 1100W" vs. "Using throttle uphill I'm getting 15mph while sitting at around 900W" please?

It SHOULD be peaking, whatever you're going to get, while pulling wide open throttle.

What kind of connectors and size of wire between the battery and controller? The controller can't pass any more than it's getting.....

Battery voltage sag from a partially charged battery?

C-5 setting?

From a dead stop it peaks at 1100w and then goes down as I get up in speed. When I go uphill it hangs around 900w even though I'm going slow.
C5 is set to 10 which is the highest.
Xt60h cables. They're the same size as the controller's cables.
Voltage sag is only .2v.
Full charge

 

[AHicks]

"When I go uphill it hangs around 900w even though I'm going slow."

Is there a chance you're getting the motor hot enough to trigger some sort of internal device that's slowing it in an attempt to keep it from over heating? Or same question differently, how long does it take to slow to 900w from 1100w?

My thought is still the fact that controller can't pass more than it's getting. Any signs of heat at those XT60's? There are very similar XT90's available if you see anything going on there. Have you opened up the battery case to check the wiring in there? Maybe spot a bottleneck in there as well. Like an undersized (restrictive) fuse holder for instance?

 

[Ridersofthenorm]

"When I go uphill it hangs around 900w even though I'm going slow."

Is there a chance you're getting the motor hot enough to trigger some sort of internal device that's slowing it in an attempt to keep it from over heating? Or same question differently, how long does it take to slow to 900w from 1100w?

My thought is still the fact that controller can't pass more than it's getting. Any signs of heat at those XT60's? There are very similar XT90's available if you see anything going on there. Have you opened up the battery case to check the wiring in there? Maybe spot a bottleneck in there as well. Like an undersized (restrictive) fuse holder for instance?

I only really see 1100w when pulling out of my driveway and it's only for a second. After that it's 900-1000W. I did a test that I don't want to do a lot, but I put my feet on the floor for resistance and pulled the throttle for just a sec and it only went to 1100w


I ordered some Xt90 cables that arrive in a day or two. Will switch and report back on that. If that doesn't work then I'll open the case. I think it may be the wires though since the default wires coming from the battery plug are 14awg and I had to extend it from that. So I'll try upgrading them. Thanks

 

[Ridersofthenorm]

Something else I noticed that is different than my other bike is that when I press the throttle from start, the display takes about two sec to read my speed/wattage. Whereas it's basically instant on my other bike. I didn't actually know that the KT display has a "loading" sign for readings until this bike lol.

So I think maybe there is a connection with some resistance.

In order to put the controller there, I had to extend the battery wire. I cut the two wires from the controller and soldered 14AWG (Xt60 pigtail) wire to the controller wires to extend it. Those wires travel from the controller, under the bike and up through the bottom of the tube, connects to an Xt60 connector that is the connected to the battery plug. The entire length of the cable is probably12-15in and it's pretty tightly pulled.

https://imgur.com/dQhllsV

I have a second mounting bracket battery plug from Ride1up. I ordered it from them just in case when I ordered the bike. So I will be replacing the 14agw wire with new 10agw wire onto those pins. However, this will be my first time soldering wire onto pins this thick. Do I use any special solder or just the regular 1/26in solder like this:

https://www.harborfreight.com/media/catalog/product/cache/9fc4a8332f9638515cd199dd0f9238da/i/m/image_21064.jpg

Or can I just heat up the existing solder and push the wire through, wrap it around the pin and heat shrink it?

https://imgur.com/VL9CNAS

The new wires arrive tomorrow so will be working on it then

 

[AHicks]

Sorry, scared to answer your question. SO MUCH of this depends on experience and the tools you are working with!

I will say I would probably make every attempt at desoldering any connection previous to connecting a new wire. Be careful, best of luck. -Al

 

[Ridersofthenorm]

I will just cut the 14 awg wires short and solder the 10 awg wires to the shortened 14 awg wires then. Will go to an electrician and have them completely replace the wires on the other spare plug I have. From what I read, 14 awg can supply 30A over a short distance and most controllers have 14 awg wires anyways so I think it'll be alright without having to completely replace the wires from the pins. I think where my problem is, is using a 14awg extension cable which is probably too much resistance with it being a thin ext cable over that length.

 

[AHicks]

A thought occurred to me regarding this slowing down thing. I know, pretty pathetic right? If this P3 setting is not already set to "P3=1", try that.....

From the manual-
"P3 is for power assist control mode, when P3 parameter setting is1, power assist control mode is gear 5 of "imitation torque control" mode, when P3 parameter setting is 0, power assist control mode is gear 5 of "speed control" mode."

By way of explanation, "imitation torque control" is chinglish for power based, where the controller doesn't give a darn about your speed. This as compared to "speed based" that MIGHT try to act just like what you have going on.....

 

[Ridersofthenorm]

I have still been troubleshooting this with Ride1up. Others in the FB group/other forums say they easily get 28mph on theirs on flat but I have to pedal hard to see 24-26mph on flat. I'm only 155lbs, bodybuilding/martial arts for a decade and so I'm not out of shape.

I hooked up the cruiser to my old DIY bike, just plugged the controller cable from the cruiser to the motor of the DIY and hit the throttle. After some tests, the DIY motor uses 25-30% more power than the cruiser's motor. The top no-load speed is 41mph as expected since it (I guess) has a higher rpm.

I'm not sure if there could be something done internally to the cruiser's motor from the factory that would limit power or rpm aside from winding. Not sure if it's possible that they have some sort of safety sensor in it that regulates it or if that's possible. But I get accurate wattage on the DIY motor instead of the cruiser's.

I saw a post from a user in the fb group that said theirs seem to get to a certain speed and then it slows itself down rather than coasting at that speed which is what I also experience. Like the motor thinks it's going too fast and then slows down.

Like, if there is a tiny hill, it'll ramp the power draw up and after the hill the motor will actually speed me up for a second because it's still drawing that power that it needed for the hill which will put me at a higher speed but then it'll cut it back because it's no longer going uphill and will slow me down.

Idk a lot about sensors but is it possible to be related to a torque sensor or something?

Another thing I experienced on a long flat road going full throttle is that after a minute or two, the motor started vibrating and shaking until I released the throttle for a moment and re-engaged it.

 

[AHicks]

Your "P3" setting please?

 

[Ridersofthenorm]

P3 = 1