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Electronic throttle lock with brake release, and slight power adjustability

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    Electronic throttle lock with brake release, and slight power adjustability

    Tommycat pointed out the existence of this throttle "cruise control" in another thread. On the vendor's website for this device, it simply states, "works in parallel with most ebike throttles and ebrakes" but nothing about Bafang compatibility.

    It's not a true cruise control in that it doesn't monitor the bike's speed and adjust accordingly. It only supplies the throttle signal, in parallel with an existing throttle - it cannot be used to replace an existing throttle though, because of the way it engages.

    It does monitor the brake cutoff circuit, for safety reasons. The left-handed handlebar control mounting band is about 5mm wide, and the unit stands off the bar to fit over (at least the standard Bafang) brake lever, as well as the grip:
    Click image for larger version  Name:	unnamed.png Views:	1 Size:	69.3 KB ID:	91903

    It's relatively inexpensive, so I decided to give it a shot. It does have a connector on the end of its rather long wire, that is not Bafang compatible. I decided to splice it into an 8" main harness extension cable to minimize connection impact, and to make it easily portable or removable in case it turned out to be a POS.

    There are four wires from the control that matter, as follows (there are actually three more wires that are clipped back and not connected):
    Red To throttle power +5V
    Black To throttle ground
    Green To throttle signal
    White To ebrake signal

    Here's the main harness wires:

    Click image for larger version  Name:	main_harness_conn.png Views:	1 Size:	20.1 KB ID:	91904

    All but one of the four control wire colors match the harness wire colors, the one exception is that the control green wire ties to the harness blue wire:

    Click image for larger version  Name:	tl_splice.jpg Views:	1 Size:	102.0 KB ID:	91905
    I spliced the control wires into the harness extension wire (three wire twist), and heat-shrinked each joint, then added a new outer wrapper using glued triple shink heat shrink tubing. I then fitted the control onto the rather busy now left bar of my BBSHD Salsa Marrakesh, shift sensor-ed 8-speed IGH bike:

    Click image for larger version  Name:	20190819_100828.jpg Views:	3 Size:	67.1 KB ID:	91908

    Does it work? Yes - you need to engage the thumb throttle first, then press the blue "cruise" button on the control. I can't do this one-handed and have to reach over with my right hand. I think the cruise control reads whatever voltage the throttle is putting out and mimics it - for example at half throttle (via your finger), the cruise control mimics half throttle when enabled. Once engaged, the cruise LED will light and the throttle will be locked. [update - I have since moved it to the right-side on two installations (throttle on the left)]

    The "+/-" buttons do work, but only for 3-4 increments - on mine, you hold down the "-" button till the cruise LED starts blinking (indicating it's at the end of the range), At the lowest setting the motor (per the display) seemed to be limited to about 200 watts, and the thumb throttle could override and increase power. Another push of the "+" boosted to about 350 watts. One more, 500-ish watts. After that it seemed to have no effect (full throttle). Not unlike the somewhat "on-off" nature of the thumb throttles.

    Hit the brakes and the cruise LED goes out and unlocks. There's no "resume" power setting memory.

    My first test run was about 20 miles over rolling terrain. I'd first start out from stops, get up to speed, set the throttle, and use the gear shifter to match the terrain as long as I could. When the shift sensor activated, the lock was unaffected, so I could row up or down the gears no muss no fuss. I forgot to do any real evaluation of the lock (at its lowest power) versus PAS. I suspect the interaction would be little different than with the thumb throttle, only perhaps easier to maintain - I find holding the thumb throttle at partial settings hard on the 'ol thumb.
    Last edited by ncmired; 08-10-2022, 01:28 PM.

    This ended up in moderation but is approved now


      Just wanted to say what a well done and informative write up! I especially like the part where you can use the gear sensor without having to reset the device. I recommend sending a copy to the "parts" section for easy access...

      Best regards,
      Last edited by Tommycat; 12-19-2019, 05:39 AM.
      See my completed Magic Pie V5 rear hub motor E-Bike build HERE.


        Hello All ...Any idea where someone could buy one of these Crystalyte Cruise Control switches ... I have a Magic Pie 5 that has cruise and I'd like to try to use this instead of the button nice to be able to adjust the speed up and down a little ...


          Not a source, but an parts availability update, I guess - I purchased two of the units from EBIKESSSF in 2019, but they've since folded. The third I found on eBay in 2020, via an automated search. All still are in use, but I've not searched around for any more since.


            Some possible overseas sources:



            A U.S. based company (Hi-Power Cycles) selling via a Netherlands eBay site:
            Their U.S. web site is:


            • diverdon55
              diverdon55 commented
              Editing a comment
              Thanks for the Leads .... Found 1 at the Hong Kong Crystalyte Store .... Paid today ...on it's way ..