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'09 Trek Soho - Belt drive, Luna Wolf Pack, Tong Sheng TSDZ2 mid drive

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    '09 Trek Soho - Belt drive, Luna Wolf Pack, Tong Sheng TSDZ2 mid drive

    Here's my build of a 2009 Trek Soho. It's the gates belt drive, Shimano 8 speed internal geared hub, Luna Wolfpack battery with Panasonic cells, and a 52v Tong Sheng TSDZ2 mid drive. It's marketed as a 52v 750w motor.

    The fortunate part of this was that by moving the 55t front chain ring to the inside of the 130bcd chainring adapter for the TSDZ2 it produced a chainline ( beltline ) that aligned very well. On the belt drive there is very little room to move away from the original chainline because the belt cannot bend or flex sideways like a chain is able to.

    Only time will tell if this system is durable. I replaced the stock nylon gear used in the TSDZ2 with the available brass gear. No concerns so far but it's early days.

    The 2009 model of the Trek Soho uses the mechanical Shimano brakes. These are a low maintenance system suitable for urban commuting - but they are not mighty powerful stoppers so that aspect of the project is not ideal. Some powerful hydraulics would make more sense here. In my case that would have required additional money for a new bicycle to start the project with and I was trying to assemble a nice machine using what I had.

    The result so far has been great. Makes a type of super-commuter bike. The Luna battery looks good, and the TSDZ2 is compact and tidy.

    The TSDZ2 I have is a 52v version and I've set the software to run a max of 15amps. In this configuration I'm covering my 11.5km commute (one way) in 27-32mins elapsed time. Max realistic speed is 40kms in 8'th gear on level of slight downhill and a quick cadence. I must say that 40kms is lots of speed for commuting. With a brisk pedal effort speed is usually 30-35kms, slower on steep sections. The motor drive sound is just a bit louder than wind noise past my ears and often I don't hear it at all.

    I don't have experience with other drive systems so I can't say how his compares to bafang, cyclone or hub drives. My opinion is that the TSDZ2 is a mild drive. It's not a hotrod or an electric motorcycle. It has both cadence and torque sensors. It produces a natural pedalling assist feeling. It's still me pedalling my bike, but it's a lot easier to pedal, easier to go faster, and easier to pedal up hills. In my setup, while it has a thumb throttle, I don't sit back on the throttle and zoom along without pedalling. It will drive me forward on the throttle only, but speed drops significantly. I think the supplied software limits the max power the throttle will apply so for me I feel the urge to kick in with the pedals and zoom along at a faster pace. It's that or I'm just motivated to get to work and home as fast as possible.

    The front chainring does brush the plastic cover on the bottom of the motor. That cover protects the wiring to the motor and covers an empty cavity in the motor housing. It's not perfect, but there's no room, not even 1mm, to attempt to adjust. Doing so would result in an unworkable chainline for the belt.

    pics:

    #2
    Thanks much for this write-up - not much around here on/about that motor. Nice to hear that it can "tuck in" tight to hit a difficult belt line. Does the frame have a kickstand plate - if so, does the motor intrude in that space? Also, the motor have temperature sensing/protection by chance?

    Electric-assist commuter bikes are the nuts ...
    Last edited by ncmired; 10-31-2018, 03:07 PM.
    BBSHD / BBS02: Nexus / Alfine 8: 1 2 3 4 5 6, Rohloff: 1 | PHOTON: Alfine 8: 1 2

    Comment


    • gadgeteb
      gadgeteb commented
      Editing a comment
      The motor is expected to brace the frame using the gap behind the bottom bracket where a center kickstand is often mounted. On my frame that spot did not allow for the bolts to align well enough to use the supplied motor mount/brace. I was able to make my own fitment for this so the motor is braced to the frame and will not rotate or move. Motor does not come with a temperature sensor. There is an open source firmware project on github that will use the throttle input to the motor controller to receive a temperature sensor signal allowing for thermal protection. And the interweb has instructions on how to add a temp sensor to the motor. I may go that way in future. So far my thermal protection device is to use my hand against the motor casing — very precise.

    #3
    Wow, a mid-drive that can achieve a Shimano 8spd IGH belt line; with a huge front belt ring no less.

    How loud is that TSDZ2 mid-drive? Is it whisper quiet like a Bafang BBS02B?
    MOVING BACK TO PEDAL...
    2020 Banshee Paradox V3 1x11 (pedal)
    2018 Soma Wolverine 3spd IGH Belt Drive (pedal)

    Comment


    • gadgeteb
      gadgeteb commented
      Editing a comment
      This motor is not whisper quiet. I replaced the motor’s nylon gear with a brass gear. You can hear the motor at low speeds. When at cruising speed the wind noise will often drown out the motor sound. I do not find the noise loud. It’s a machine and you hear it.

    #4
    Hey, neat build, thanks for showing it off. That drive is TINY! It just disappears on your bike. I hadn't seen it on a bike yet, it's very stealthy.

    What else are you able to tune in the settings, besides max current? Do you have access to the torque and speed parameters, to change the way the bike reacts to your pedal inputs?
    Fabrication is fun! Build something today. Show someone. Let them help. Inspire and share. Spread the desire.

    Comment


    • gadgeteb
      gadgeteb commented
      Editing a comment
      In the system settings You can set wheel diameter, max amps, max speed (up to a max of 45kms), a walk assist. With the buttons on the display you can toggle through distance, speed, trip time displays and you can adjust the assist level. Assist level determines how much motor assist is added against the force you apply to the pedals. So on “turbo” light pedal force applies max motor assist, eco mode means you pedal more strongly with less motor assist.

    • JPLabs
      JPLabs commented
      Editing a comment
      I see. Thanks.

    #5
    Originally posted by gadgeteb View Post
    In my setup, while it has a thumb throttle, I don't sit back on the throttle and zoom along without pedalling. It will drive me forward on the throttle only, but speed drops significantly. I think the supplied software limits the max power the throttle will apply so for me I feel the urge to kick in with the pedals and zoom along at a faster pace. It's that or I'm just motivated to get to work and home as fast as possible.
    ... As assist should be.

    Originally posted by gadgeteb View Post
    The motor is expected to brace the frame using the gap behind the bottom bracket where a center kickstand is often mounted. On my frame that spot did not allow for the bolts to align well enough to use the supplied motor mount/brace. I was able to make my own fitment for this so the motor is braced to the frame and will not rotate or move.
    I've looked at the installation manual, and have some ideas - can you post a picture of what you cobbled up?

    Originally posted by JPLabs View Post
    What else are you able to tune in the settings, besides max current? Do you have access to the torque and speed parameters, to change the way the bike reacts to your pedal inputs?
    There's an open source firmeware project underway, which may make on-the-fly setting tweaking directly available via the display.

    I asked about temperature sensing/protection because the motor looks like it doesn't have much mass - and 750 watts is getting up there.

    Isn't it more than about time for "take three" of Bafang's BBS motor series?
    Last edited by ncmired; 11-05-2018, 10:08 AM.
    BBSHD / BBS02: Nexus / Alfine 8: 1 2 3 4 5 6, Rohloff: 1 | PHOTON: Alfine 8: 1 2

    Comment


      #6
      For the rear mount I happened to have an odd style of bolt that fit into the motor but that turned into a 12mm or so diameter cylindrical "post". Threaded into the motor it made a sturdy motor mount. I then used a small hose clamp around the frame member behind the seat post between the chainstays.

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        #7
        I'm working on the same bike. I long ago ditched the front roller brake (as did Trek, going to discs in 2012). The front roller has a torque limiter to prevent idiots from going over the bars, but for a big guy like myself, it was dangerous. I installed a cheap double pivot sidepull, which also allowed me to go to a lighter and stronger radial spoking.

        What 130BCD adaptor did you use? I've had a plan to just use standoffs to set the beltline, then fabricating some offset drag links to connect to the next trailing chaining bolt to carry the torque, but it looks like using the TSDZ2 mid drive and that adaptor you've managed it.

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          #8
          Got a TSDZ2 for Christmas. Fitted it to my Trek Soho encouraged by this thread. However the belt doesn’t appear to line up and wants to move inward towards the bottom bracket. Any suggestions?

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