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BOOM! a Grom Clone

Discussion in 'Electric Motorcycles' started by brian72, Jan 2, 2016.

  1. liberpolly

    liberpolly Lazy rider

    Joined:
    Sep 21, 2015
    Oddometer:
    6,683
    Location:
    Seattle
    So you use DC to DC converter only to charge the batteries?
  2. Reap

    Reap Adventurer

    Joined:
    May 12, 2020
    Oddometer:
    25
    Location:
    Mississippi
    No it converts electricity for the entire bike your lights etc will not work if you do not do this right. If this is all new to you and your not familiar with electrnics I do not recommend taking on the this project on the new model. I had to swap some connectors between the old and new controllers and solder wires (you can splice wires without solder but solder works best). The throttle wires and high brake wire is put together in one connector on the original controller but most other controllers, like the one I posted, will seperate throttle wires and high brake. If any of this sounds daunting do not attempt this upgrade, it is not easy like it was for the early posters.
  3. liberpolly

    liberpolly Lazy rider

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    Sep 21, 2015
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    Seattle
    So it converts the high voltage of the new combined batteries to the lower voltage that the bike can use? Why not just connect the batteries in parallel instead?
  4. Reap

    Reap Adventurer

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    May 12, 2020
    Oddometer:
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    Mississippi
    Im not sure what your thinking of where its confusing or if Im misunderstanding but if the batteries were parallel you would bot be riding this bike.
  5. thismoththo

    thismoththo n00b

    Joined:
    Apr 27, 2020
    Oddometer:
    3
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    Nys
    Hello all. Had my e grom for about 2 weeks now. Have a few things changed, more on the way. Will post pics momentarily. Question about steering; is anyone else experiencing stiff steering and clunky shocks? Compression and rebound are ok, a little on the hard side, but I'm concerned about the stiffness of the actual steering and the sounds I'm getting with bumps.
  6. thismoththo

    thismoththo n00b

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    Apr 27, 2020
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    Nys
    Late-night update.. 20200607_202522.jpg 20200607_202424.jpg
  7. ikev85

    ikev85 Adventurer

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    May 18, 2020
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    18
    Location:
    Columbus Ohio
  8. Reap

    Reap Adventurer

    Joined:
    May 12, 2020
    Oddometer:
    25
    Location:
    Mississippi
    See if you can turn fine at low speed, the stiffness at higher rpm is likely due to the speed your going on a street tire. I think you have to lean into your turns at high speed rather then simple turn the wheel. (New to riding bikes but thats what I noticed its probably bad to be able to turn hard at high speeds?)
  9. Reap

    Reap Adventurer

    Joined:
    May 12, 2020
    Oddometer:
    25
    Location:
    Mississippi
    Went ahead and bought a Zero Motorcycle going to sell my eGrom. The eGrom accelerates 60% faster now with controller and battery upgrades but the motor is locked to 40mph. So if thats fine for anyone near Mississippi Ill sell my bike to you for $1400. I put $500 into upgrades which included a more powerful controller with bluetooth customization.
  10. simplemind

    simplemind Been here awhile Supporter

    Joined:
    Jun 12, 2009
    Oddometer:
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    Location:
    Austin/Telluride
    Which ZERO?
  11. Reap

    Reap Adventurer

    Joined:
    May 12, 2020
    Oddometer:
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    Mississippi
    I got the Zero S, I feel like Inshouldve got it to begin with but the eGrom was nice to learn on.
    liberpolly likes this.
  12. roadpupp

    roadpupp Adventurer

    Joined:
    Jan 22, 2012
    Oddometer:
    13
    Location:
    New haven CT
    Hey all-
    This thread has been great. I bought a 2019 E Boom Vader from Belmonte Bikes in May and received it after about two weeks. 72 volt 2000 SLA version.

    I am an old sportbike guy and bought this as a second bike for me and for my wife to ride around our beach neighborhood. I have lots of upgrades planned and in the works, but not much done yet. I have been modifying my kids Razor RSF 650 bike (over volt, internal shunting, brake upgrade).

    So far:
    2019 Grom SL forks ($250 on ebay) took 5 minutes to swap. HUGE improvement over the stock forks. Seriously.
    $160 rear shock from Ruckshop.com. (haven't installed yet)
    Rear fender delete and integrated tail light from Ruck shop
    Upgraded scooter levers/reservoirs (better look and feel)
    Brembo one pot front brake (not installed yet)

    QS Motors 72 volt 8000w V4 hub motor 13" x 3.5" just ordered. Should be here in 60 days.
    Greentime 80 Amp controller Just ordered. 60 days out supposed to be easy to shunt and get faster

    My thinking has gone several places lately and I would love any feedback:
    My goals with this bike are varied.

    Fun scooter around town for the wife and myself.
    Not necessarily wheelies but LOTS of power down low.
    Ability to do 60 MPH so I can take the highway bridge a few exits (also because its fun)
    Range is not as important but 30 -40 miles would be good.

    My plan is to get the non electrical upgrades done this month waiting for motors and controllers. Brakes and lighting and shock. The motor is a direct swap and the controller will be a bit of work to get all the wiring correct. The Boom doesn't seem to have an accurate wiring diagram so should be an adventure.

    My big question is the battery pack. I have been planning to use Nissan Leaf cells. I built foam mock ups of the 12 x 9 x 2 cells and am not sure I can get 10 of them in the battery pan/tank area. I need 10 because my motor is 72-96v.
    If I fail to get the 10 foam mock ups to work, I am interested in Lifepo or other options. https://www.ebay.com/itm/48V-40Ah-Ternary-lithium-Battery-2500W-Ebike-Bicycle-Electric-Motor-Scooter-BMS/324092408647?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m2749.l2649

    I have never built an electric bike before but this has been a great platform to mess around with E bike stuff. I will post pictures as I go along.

    One thing, I am surprised to learn from a recent post that the controller on the newer E Groms won't do 96v. I haven't tried it but was planning to as a test before buying a pack.

    Thanks all Great thread!!
  13. MJSfoto1956

    MJSfoto1956 Been here awhile

    Joined:
    May 12, 2017
    Oddometer:
    510
    Location:
    Boston, MA
    the QSmotor 8000w V4 readily sucks as many amps as it can get. If your battery/BMS is not up to the task you will find them failing. I know this from experience. My BMS is more than capable, but the battery I built is not up to the task. As such I had to dial the BMS back. I still love the QSmotor V4 8000W though and feel it is a great investment. I will have to rebuild my battery pack from scratch though if I ever want to get the most out of this motor. In the meantime, I have a lovely 60mph scooter that is ideal for doing errands. However, no chance at any burnouts (assuming that is your thing).
  14. johnnyddn

    johnnyddn n00b

    Joined:
    Jul 15, 2019
    Oddometer:
    6
    Location:
    Las Vegas
    roadpupp - What brake levers did you upgrade too? I wanted to upgrade the levers and reservoirs on mine. Even with the fluid topped off and brakes bled, they still feel like crap.

    I'm also interested in upgrading the forks. Can you measure your 2019 Grom SL forks at the clamps? Mine are showing 41mm at top triple clamp and 45mm at the lower clamp.

    I'm also going with Leaf cells. I just purchased an entire Leaf cell battery pack from a wrecked Leaf. I'm still waiting for the yard to pull and ship the pack so hopefully the deal goes through. I think I will able to fit 10, maybe 11 or 12 but you would have to cut up or fab your own faux gas tank. I started a thread a while back on endless sphere.

    https://endless-sphere.com/forums/viewtopic.php?f=10&t=105324

    But from my measurements, I believe you can get 10 cells in there arranged like this:

    [​IMG]

    [​IMG]
  15. roadpupp

    roadpupp Adventurer

    Joined:
    Jan 22, 2012
    Oddometer:
    13
    Location:
    New haven CT
    MJS-
    Can you tell me more about your experience with the 8K motor? So it has tons of power but drains the pack quickly? They were recommending a 6K watt motor originally. Perhaps they understood the size of the pack needed.

    What are you thinking for a better matched pack?
    Thanks
    Roadpupp
  16. roadpupp

    roadpupp Adventurer

    Joined:
    Jan 22, 2012
    Oddometer:
    13
    Location:
    New haven CT
    Johnny-
    I got the levers from scooter Tuning. I got the cheaper ones with the round reservoirs. I wanted Black with red adjuster levers like in the photo but they came all black. I had the red adjuster levers from an old busted set. so they swapped on. Look so much better, though the original brakes didn't feel too bad at the speeds I am riding. Levers and a brembo one pot up front should be plenty of stopping power.

    https://www.scootertuning.ca/en/bra...hydraulic.html?search_query=Adelin&results=15


    The forks appeared the EXACT same length when I laid them next to each other. I don't have calipers to measure diameter but they fit perfectly in the triples. 5 minute swap. Much better feel, I am not a big guy so I have not bottomed them out yet. Perhaps when I get more power I will.

    [​IMG]

    Awesome that you are working toward a Leaf battery pack. I will be anxiously watching what you can achieve and would be happy to swap ideas.
  17. MJSfoto1956

    MJSfoto1956 Been here awhile

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    May 12, 2017
    Oddometer:
    510
    Location:
    Boston, MA
    It’s not so much the amount of drain but how much sag the battery delivers when power is demanded. Originally I designed my pack for a 4000w motor. But after my battery was complete I needed a replacement motor and instead just replacing what I had, opted for the 8kW V4. The first time I plugged it in it fried my cheap controller within 30 seconds! I then upgraded to a controller which is capable of 600a but had to dial it back to half that. With an upgraded battery I’ll be able to dial it back up to 600a and it should then be able to fully take advantage of the 8kW V4 QS hub motor.

    you can read about my project here: https://advrider.com/f/threads/my-ezuma-project-elektra.1340153/page-9#post-38740746
  18. roadpupp

    roadpupp Adventurer

    Joined:
    Jan 22, 2012
    Oddometer:
    13
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    New haven CT
    Thanks MJS
    I am leaning toward the Powervelocity controller. Just to need to get the pack set. My motor arrives Wednesday!!
    MJSfoto1956 likes this.
  19. BobDz

    BobDz Adventurer

    Joined:
    Dec 23, 2017
    Oddometer:
    21
    Location:
    Chicago area
    So I ended up burning up my stock controller before the end of the season. Picked up a 96v Kelly controller, definitely a lot larger . I think it will make the bike a little bit cleaner mounting it on the inside of the fairing (drill a few holes in the front for cooling). Going to be an interesting winter...

    Attached Files:

  20. roadpupp

    roadpupp Adventurer

    Joined:
    Jan 22, 2012
    Oddometer:
    13
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    New haven CT
    Woah- That controller is big! I bought the KS-S mini that is rated for 120A-300 Peak. I need all the space you used for the controller for my leaf batteries. Hopefully 120A continuous makes me happy. Please let us know how the controller and SLA batteries pair up.

    I fabbed a deeper box for my Leaf Cells. I am able to get 11 cells in the box and stacked on top of the others. Will need to mock it up to see if it sits too low. The bigger rear wheel should help. The metal of the box is so thin, I could only tack it to the thicker material I plasma cut to make the extensions. Once it proves to work, I will JB weld on the outside and silocone on the inside to make it waterproof.

    [​IMG]

    [​IMG]

    [​IMG]