All hail your new bicycle God!!!

Discussion in 'Photos & Bicycle Builds' started by evil_genius, Mar 8, 2014.

  1. evil_genius

    evil_genius New Member

    Just kidding, but this is one freakin' sweet ride. It's probably around 95% complete, still a few tweaks to be done.

    Magic Pie III on the front, with a 28cc Bumble Bee on the rear. If Satan had a BMX, it would be this BMX. :devilish: Just a little South of insanity. Sometimes it's legal, sometimes it's not. I took it out for a test run this afternoon, and it will leave about a foot of rubber on the street if you throttle to the max! I had to reprogram the acceleration on the pie back to 85% to keep it stable. Using the GPS speedo app, this is what I got:

    Magic Pie only: 35.0km/h (fast acceleration)
    Gas only: 43.6km/k (pretty slow acceleration, boooo!)
    Both: 50+??? Didn't have the GPS on, but it pulled pretty hard for a small bike. I'd compare it to riding a 66cc cruiser, but with a little less top speed.

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  2. wheelbender6

    wheelbender6 Well-Known Member

    Whew! 50mph on a BMX bike!
  3. keatonx

    keatonx Member

    I think he meant kmh lol
    Hamzsim likes this.
  4. keatonx

    keatonx Member

    Although I do plan on doing that with my rotary engine powered BMX I'm making:helmet: :evilgrin:
    Hamzsim likes this.
  5. butre

    butre Well-Known Member

    I've been thinking about putting an electric hub on my bike, it's a really cool idea. Hybrid 2wd, maybe even ditch the heavy battery for a much lighter one and run it mostly off an alternator. Having the electric front hub would mostly eliminate the need to bump start as well.
    Hamzsim likes this.
  6. wheelbender6

    wheelbender6 Well-Known Member

    I have contemplated a combo electric and gas powered bike many times. Gas motors must gain some rpm before providing significant power. However, electric motors provide significant power at a very low rpm. So, i would use a 24v electric geared hub motor for acceleration from the standing starts and then gas power alone at cruising speed. The hub motor could also be used for help with climbing hills and fighting headwinds. A geared hub motor would cause no drag when not in use and 24v LiPo batteries don't add much weight.
    Hamzsim likes this.
  7. Hamzsim

    Hamzsim New Member

    Swweeeeet ride dude
  8. KCvale

    KCvale Motorized Bicycle Vendor

    Won't work.
    Your 66cc stroke engine could barley run a generator for full power to the electric hub at full throttle and you have a 20-30% loss of power converting the engine power to a generator opposed mechanically to the wheel.

    Do some research on how cars do it because even trying to run lights off the engine make you keep the revs super high.
  9. IbedaYank

    IbedaYank Member


    super high rpms are needed KC??? Then explain why do these PTO SHAFT powered generators run at a low rpm of 540. average car runs at around 700rpm at idle and yet the alternator still supplies enough voltage/amperage to charge the battery. KC now why is this possible???????? Oh yeah because the main pulley on the crankshaft is 5 times bigger then the one on the alternator. So if the main pulley is turning 700rpm the alternator is turning 3500 rpm.