My 1st 80cc Fat tire Evo

Discussion in 'Photos & Bicycle Builds' started by djat806, Oct 26, 2015.

  1. djat806

    djat806 New Member

    Hello , all I'm new to the forum. I'm looking to get my chain to clear the rear tire with is 4.0 big. Ive been doing my own research and came up with the BikeBerry Sprocket Adapter as an option . Firstly how do I figure out of I need the 1.0 or the 1.5 hub also will this item work. Or is there any cheaper alternatives. Here are a few pics I'll post more if needed.

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  2. KCvale

    KCvale Motorized Bicycle Vendor

    Welcome djat,
    Just a note, there is no such thing as an 80cc, it's a 66cc for accurate future reference ;-}
    Unfortunately just moving your rear sprocket out won't do it.
    That 415 chain has to be in alignment.

    Your engine sprocket is inside the tires width mounted to the seat post, ~2.25" tires is all it can get by.

    That means either also making an offset 2-stroke engine mount for front and rear, use a different system like a friction drive, or just 'jackshafting' your engine output to the right hand side and using the pedal system to drive the wheel.

    SickBikeParts has a 2-stroke JS kit that works well for $200.

    You mount the engine to the JS base, then mount the unit to the bike, and then change out your bottom bracket pedal system that will share the pedal drive with the engine and not beats your legs off.

    Read the install instructions as it's complicated and may be above your skill/tools level but what I use for everything with over 2.25" tires like this one.

    No extra back wheel sprocket, the engine goes to shaft.


    Then, you use the pedal side which is already wide enough to clear your fat tire on the right.


    Bummer you have no rear wheel gears you could use with it as well, but it's better than trying to go the other way as you want your engine secure to the frame.
    djat806 likes this.
  3. djat806

    djat806 New Member

    Thanks for all the help I should receive the adapter next week and my universal mounts , also I tried out the cnc machined mount with no luck , it hits the muffler , anybody run into this?
  4. KCvale

    KCvale Motorized Bicycle Vendor

    You are still trying to go direct drive on the left?
    Well, you were warned it wouldn't work, but hey spend away.
    djat806 likes this.
  5. djat806

    djat806 New Member

    OK after , trying universal mounts and traditional mounts , the chain didn't clear as I was warned ABOVE. After tinkering around more I finally got her running!!!. I added a 1.5 sprocket adapter(, bent my coaster arm several times to get it right.Plus a occ chopper mount(, That did the trick. The chain clears the tire , I test rode it to work, posting pics when I get home.
  6. djat806

    djat806 New Member

    20151116_190825.jpg 20151116_190832.jpg 20151209_191949.jpg

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  7. KCvale

    KCvale Motorized Bicycle Vendor

    So you moved the whole engine left.
    That will work if stays in place, good for you!

    Have you done the shove test?
    Hold your top bar with one hand, your engine head with the other, and shove the engine back and forth as hard as you can.
    If it moves AT ALL, that is a fail.

    I am not sure what your final pic is...
    One pic has your carb at ~45 degree angle, that will always be a problem.
    You will know when it won't start, and the reason will be because the float can't shut off fuel and it will run straight through and pool in the bottom of your engine.

    And it looks like your tensioner is on the top (power) side, they are only designed to take up slack on the bottom (return) side.
    When that fails it's going to really ruin your day, that is assuming it hasn't already been ruined because you couldn't stop that heavy bike with just that wimpy coaster brake and crash.

    Sorry to rain on your parade as you really put a lot of effort into a loosing battle.
    In short I suggest you check your medical coverage and ride in full body armor as I wouldn't ride that death trap around the block no matter how 'cool' it looks because I know first hand how 'un-cool' it is to wreck by going faster than brakes, which in your case is about 10mph.
  8. djat806

    djat806 New Member

    Thank you taking everything into consideration , as of now the bike rides welll. I'll keep u posted.
  9. Blotmo85

    Blotmo85 New Member

    Hey! How did you get the coaster brake arm on the hub with the rear sprocket mounted???
  10. KCvale

    KCvale Motorized Bicycle Vendor

    It's been over 5 months since a reply, I think you can figure whatever he tried didn't work.
    I tried to warn him, I just hope he's not hurt.
  11. bakaneko

    bakaneko Active Member

    He could be just fine and dandy, and don't post much. I've seen these fat tire 2-stroke builds before and they work fine. He just needs to upgrade his brakes or at least the front brake.
  12. Hello Moto!

    Hello Moto! Active Member

    Hey KC, is the bike you have pictured a FITO Modena? I've actually come across that bike when I was looking for something better than my roadmaster to put a motor on. You did an excellent job. I really like the front forks on those bikes. It just looks like it was built for a motor lol.
  13. KCvale

    KCvale Motorized Bicycle Vendor

    Yes Moto, this a motorized Fito Modena GT 7-speed.


    I have never cared for straight hard triple-tree forks, too stiff and they hit the top bar when you turn, hence their bumpers.
    They are pretty cool with a real shock fork though.


    It adds ~$100 to the cost but worth every pothole and speed bump you hit and don't feel.

    They don't make the silver one anymore, just black now. What a dumb move in my opnion.

    I tried to make the top tube a gas tank. Though it can be done it only holds a couple cups of fuel if memory serves, not enough to be useful.
    If you want pictures and details about how I did the 'top mount' gas tank they are here.

    The second bike used the 'extended tank bolts' mount. It doesn't look as cool but is much sturdier.

    The solution to the top bar not being big enough is a similar frame that has a tank built in.
    Hence the new GT2-150 gas tank frame mods for fatter tires and a rear disc brake, my Fito builds spawned the frame changes.


    Ya I know, different engine, but the premises is the same.
    I just move the Fito's parts to the GT2 gas tank frame.

    I suppose I should do a Silver 2-stroke just for comparison to motorizing a Fito but I'm sick of 2-stroke and moving to 4-stroke.

    The GT2 frame is longer so it's wouldn't be to scale against a Fito, but the frame has a 2-stroke mount.
    The big factor is the added cost vs. benefit.

    That is a topic for another day but that is the basics of using the Fito as a base, hope it helps.
    OTP likes this.
  14. djat806

    djat806 New Member

    im . im alive?
  15. KCvale

    KCvale Motorized Bicycle Vendor

    Chances are high you are living.