PAS is faster than full throttle!

[dgk02]

I took the new Ebike for its first trip today, and noticed that the PAS mode is significantly faster than full throttle. Since it's only a QT100 motor running at 36 volts, that isn't really very fast but it was unexpected. I'm guessing that PAS ignores the three wire "three speed" connector which comes from the throttle and connects to the controller. The controller documentation refers to it as the three speed connector but gives no information on what to do except that orange is fast, black (GND) is medium and green is slow. Since all are connected to the three wires from the throttle, I could use a suggestion as to how to connect it so that I get the fast mode. The colors do not actually match the colors in the documentation but it clearly is the proper connection.

There are two other connectors that are coming from the throttle that are not connected to the controller at the moment. One is probably the button, which I'll likely connect to the red (+) wire from the PAS sensor and hope that it works to disable PAS. The other unused connector must have something to do with the battery level lights, and that is handled by the Display unit so is not necessary on the throttle.

So far it's all working pretty well, and I've certainly learned a lot.

 

[TheBeastie]

Yeah I been using my PAS on my BMSBattery CST motored 500W S12S controller setup.
I just think if I get used to it enough I will in the long term reduce an accident under certain situations by %50 because when cars see you pedal they assume your speed a lot better.

 

[mwkeefer]

Just so I understand, you saying pas doesn't respect the speed limiter switch and so it goes faster than full throttle in Speed Limited Mode

OR

Your saying that in full assist mode, the bike goes faster than no speed limit full throttle when pedaling along?

Regards,
Mike

 

[dgk02]

Just so I understand, you saying pas doesn't respect the speed limiter switch and so it goes faster than full throttle in Speed Limited Mode

OR

Your saying that in full assist mode, the bike goes faster than no speed limit full throttle when pedaling along?

Regards,
Mike

The controller has a speed-limiter wire, which I have disconnected. But the wire from the throttle is called the three speed wire. All I know is that if I have pedal assist mode on and hit the throttle, the bike slows down. I'm guessing that PAS does not pay attention to the three speed wire but the throttle does. I need to wire the throtle in fast mode but have no idea what I'm supposed to do with the three wire connector:

 

[d8veh]

I'm not convinced about that explanation of the three speed connector, although it could be correct.

The ones on the BMSBattery controllers have a middle ground (black) wire and two other wires: restricted speed and overdrive.

With nothing connected, you get normal operation. With the middle (ground) joined to one of the other two, you get restricted speed. With it connected to the third wire, you get overdrive, wherein the controller changes the timing of the FETs to allow the motor to spin faster that it normally can. On a Q100, the boost is about 2 mph. You shouldn't leave this connected all the time because it makes the motor run less efficiently at lower speed, althougj I don't notice that on my 500w Bafang .

 

[alsmith]

I just think if I get used to it enough I will in the long term reduce an accident under certain situations by %50 because when cars see you pedal they assume your speed a lot better.

I've never noticed any difference at all. Is this a personal feeling, observation, or from some formal test by someone?

 

[dgk02]

The bottom line here is that the throttle is next to useless. I'll hook up a little computer tomorrow but it seems to max out at 8 or 10 mph. I don't know why. PAS is so fast that even in lowest mode it requires me being in top gear to keep up. That is on an 18 speed mountain bike so not really very fast, but I need to do a fair amount of biking slower than that. If the slowest PAS setting is going to be too fast for biking in congested areas, it's going to be a problem.

This is a 24 volt Q100 front kit running at 36 volts.

 

[d8veh]

You need to measure your throttle signal to confirm that it's OK. Measure it woth a voltmeter by sticking your probes up the back of the connector between the black and signal (white?) wires. When you open the throttle, you should see the voltage rise to about 4v.

Another possibility is that you've connected something you shouldn't have. As I said above, one way, the three-speed switch restricts the throttle. Also there's usually a separate pair of speed restriction wires (often white).

I forgot to mention before that the overdrive only seems to work in sensored mode.

 

[dgk02]

Well this is embarrassing. Is it more embarrassing than having a brake hitting the tire and causing the burning smell? Perhaps, because I really wasn't responsible for that one. The brake was badly aligned and I just didn't notice. But I installed the throttle, brake, and grip shifter so this one actually is my fault.

The reason that the throttle wasn't going as fast as PAS was because the throttle lever was physically hitting the shifter's cable where it leaves the shifter and thus wasn't going all the way. As soon as I noticed that and rotated the throttle so that I could push the lever all the way, it hits 19 with no load. It was hitting 13 before. Much better. Still not what I'd like but better. I can see if the 3 speed cable will help out a bit here. A few more MPH would be nice but not really necessary.

I spent most of today working on the bike and buying some tools so I could get everything tight. I installed a front fender; I have one for the back but that can wait a bit. I installed a mirror - very useful.

Now I only need to get the button on the throttle to turn PAS on and off and it's pretty much set. Well, as soon as the torque arm, panniers, and sturdy kickstand arrive. And I need to figure out how to tie up and waterproof all those wires...