Crappy throttle issue with Cyclone powered fatty

[mammonista]

I'm sure this has been covered before...
A couple of months ago I finished my Cyclone Deadeye Monster build. We moved to coastal Oregon about a year ago and this fatty should be ideal for cruising the beach and the dunes/backwoods. The bike has a Nexxus 3-speed IGH hub with a 3000w Cyclone mid-drive that I mounted inside the frame with some custom brackets.
I changed the 44/44 front sprocket that the Cyclone kit shipped with for a 32/44. The original sprocket combo gave me top speed in gears of 21/26/32mph for low/mid/high on the Nexxus. Much too fast for off road/dunes riding. With the 32/44 set-up I now have 15/20/25mph or thereabouts.
I bought a much too big 20ah/48v battery that is mounted on the rear rack. Dunno what I was thinking but it does give me a lot of range.
Here's my problem the one eighth turn twist throttle that the Cyclone shipped with is a piece of crap. There is approximately 1/8" - 1/4" (10 degrees?) of twist 'free play' from the 'off' position before the cyclone starts spinnin. So the rider never really knows when the power is going to come on when going from 'coasting/freewheeling' to 'acceleration'. Additionally power delivery is anything but linear. If I had to guess it goes from 0% power to 80% within the second 10degrees
I like the idea of a twist throttle as opposed to a thumb throttle. And I like the idea of a simple, LED voltage gauge that comes with the throttle.
But is there a better quality throttle out there?
or.....
is the problem not the throttle at all and instead the controller that the throttle shipped with from you know who.
Any help would be appreciated.

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[fechter]

That's a common problem with many throttles. In some cases, there are programmable settings in the controller for throttle start and max settings. Not sure if your controller has that feature.

The old fashioned way to fix that problem is to place a resistor in series with the throttle ground wire. This raises the signal voltage. The trick is getting the right resistor. I like to use little 10 turn trimmer pots to make it adjustable. Other wise use alligator clips to any pot and dial it in, then remove the clips and measure the resistance of the pot, then find a fixed resistor that's close.

Typical values will be 100-200 ohms. When testing be sure to lift the wheel or otherwise be ready for the motor to start running.

To dial it in, start at zero ohms and slowly increase until the motor just barely starts to run, then back off a little.

Not only does this get rid of the annoying dead band, but makes the low end throttle response much more gradual.

 

[mammonista]

thankyou, thankyou, thankyou!!!!
now I just need to get your instructions into the hands of somebody who speaks volts, ohms, capacitors, resistors, potentiometers, etc.
thanks again,
mark

 

[fechter]

I wish there was an easier way to do this. A more advanced controller would be able to do this automatically.

I have also done it by adding a small piece of magnet inside the throttle, but that is even trickier.

 

[mammonista]

well it doesn't sound like rocket science...more like potato cannon science! If I read you right I need to find the ground wire from the throttle. Hmmmm? I have a yellow and blue leads in one plug from the throttle and red, green, and black on the other plug. How would I find the 'ground' lead? God knows what happened with the documentation for the kit throttle, but maybe the schematic is available on line? You're saying get some kind of adjustable resistor (potentiometer?) and temporarily wire it in line on the ground lead and then turn it until the motor starts spinning then back it off and measure the resistance across the potentiometer and get a resistor with the same value (maybe just a tad more?) and test it and go up or down a few ohms and when satisfied solder it in and live with it?

 

[fechter]

I love potato cannons....

Anyway, the ground is most likely the black wire. To make sure, you need to measure with a voltmeter between the battery negative and the wire in question. The right one will be zero volts and have continuity to the battery neg. But I totally don't trust the colors unless previously tested by someone.

Yes on the procedure. The pot should be around 200 ohms, but a higher one will work, just be more touchy to adjust.
Alternately if you have a pile of various fixed resistors, you could do trial and error. Most I've done turned out around 150 ohms.
If you use too much resistance, the motor will keep running or the controller will fault on startup and the motor won't go at all. You should have a little dead band to compensate for temperature variations.

 

[mammonista]

Yeah, now that I think of it I'm going to visit my brother up in Alsea next week (?) and I'll bring my cannon. Fun doesn't get much cheaper than that!
Well I think you've answered all my questions. The bike was dangerous to ride the last time. Would easily lift the front wheel from a dead stop and trying to finesse my way up a small sand hill would want to come over on me at the first opportunity. Trying to keep the front wheel on the ground at one or two mph got real old real fast.
It will be a different beast with a predictable, linear throttle.
If I go for a 72v battery at some point would I need to recalibrate the resistance to keep the throttle in tune?

 

[fechter]

If I go for a 72v battery at some point would I need to recalibrate the resistance to keep the throttle in tune?

That shouldn't change it.

Having some control on the ramp up speed might be good, but that is also programmed in the controller. There used to be a thing a guy made called a "throttle tamer", which was a little Arduino circuit that set the end points and controlled the ramp up rate. I don't think it's been around for a while, but the idea is good. Most of the better controllers have some kind of setting for this now days.

 

[mammonista]

dang man...I know I should buy a better controller. but I'm old now and living on a fixed income. and when I tell people my build cost me $1,500 in parts they back slowly away.

 

[mammonista]

that's the bike, motor kit, battery, etc. mind you. But still $1,500 for an eFat bike is a lot of dough.
And a quick check of programmable controllers (from China!) on Ebay tells me the cheap ones go for $200 plus. Think I'd rather try a couple of resisters first!

 

[mammonista]

So I bought a V3 Cycle Analyst...thinking that would eliminate some/all of my issues with crappy throttle response. I also bought a couple of cheapo throttles off Ebay because I wasn't really thrilled about the throttle that shipped with the Cyclone 3k from LUNA CYCLE!
But now I'm thinking my money would have better spent elsewhere.
HELP!!!!!!

 

[mammonista]

Here's a thread from another ES forum...
Not so much help (at least not hearing what I had hoped to hear.
https://endless-sphere.com/forums/viewforum.php?f=3

 

[mammonista]

oops.
https://endless-sphere.com/forums/viewtopic.php?f=3&t=94795

 

[TommyCat]

As Fechter was saying...Hall sensor throttles can be tweaked a bit. With resistors or magnet field manipulation. Is yours a candidate?

If you where to back probe the throttle cable connector and get the sensor output readings it would help. Probably Black ground and green/white output. If it varies with turning the throttle you know you have it. As always watch that back wheel...


Here is my profile that works well with my Magic Pie V5...

And here is a blank one for you.

Regards,
T.C.

 

[John in CR]

The CA V3 should be able to fix you up nicely once you learn about how to tune it's throttle capabilities. Look in the ebike reviews and testing section of the forum for the monster book of a thread. The torque throttle capabilities is what you want.