max size motor possible for in frame build

Discussion in 'Motorized Bicycle General Discussion' started by moserclassic, Aug 20, 2011.

  1. moserclassic

    moserclassic New Member

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    Looking at possible build options and was wondering what larger size engines (either 2 stroke or 4 stroke) that people have tried with success for building of an in frame chain driven combination without tons of custom fabrication (don't have the ability to weld). What types of features would be helpful to have when looking at individual engines (for example clutch sizes, etc.) and helpful in determining if the engine would work well and fit if just a kit was purchased and the engine was bought separately.

    I would assume the main limitations to what type and power of engine are weight of the engine, dimensions of the engine (ones with larger horsepower may not mount properly within a bike frame), and overall cost.

    Can anyone point me in the direction of some examples of projects that involved larger engines than what typically come in the all in one engine kits? I have searched the diy forum and found some examples but many involve significant custom fabrication which I do not have the equipment for.

    I have a high quality steel mtn bike with 29 inch wheels and very nice brakes which I will be installing the motor onto.
     
  2. The_Aleman

    The_Aleman New Member

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    There's a million answers to your extremely vague and general question you have asked. Despite what details you posted.

    No matter what, when you put an engine with over 2-3 HP on a bicycle, you are creating an illegal moped or motorcycle in the eyes of the law.

    If you want more power, go buy a motorcycle. That's my opinion and I'm sticking to it.
    When new guys show up here and immediately ask about large motors I fear for them.
     
  3. kevyleven007

    kevyleven007 Active Member

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    With your lack of skills I would say a 66/80cc "skyhawk".And yeah,If your going to go over 20mph.watch out for the law and dont hit a dog!lol
     
    #3 kevyleven007, Aug 21, 2011
    Last edited: Aug 21, 2011
  4. WildAlaskan

    WildAlaskan New Member

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    go buy a small atv motor strap it in and hold on
     
  5. Dan

    Dan Staff
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    Howdy Moser,

    On the laws thing, many states differ so would check local DMV. Some states including my own allow for up to 5 HP and many only up to 50cc. Some require registration while most don't. Just a thought.

    The largest engine I have mounted in frame was a Harbor freight 79cc. There are commercially available mounts for them that are bolt on. I made my own with a drill press and some angle-stock. For first builds, I think it would be easier to go with some thing already made and work up to a DIY build. Again, just a thought.

    No matter what you decide on, these things are great fun and you will enjoy it.

    Welcome to the forum!

    I got curious and looked up MBs on the VA DMV site. All the pages I found on " power-assisted bicycle"s seem to have been taken down. Commonwealth of Virginia Department of Motor Vehicles

    But Mopeds had this; Commonwealth of Virginia Department of Motor Vehicles

    The laws section here has this; Google Custom Search But be sure to double check the information you find is up to date.

    But honestly, I have never been bothered about engine size.

    Lots of great folks here who enjoy helping so ask any questions you have. Can almost guarantee some one will know or have tried what your thinking of doing.

    Enjoy and again, welcome. Post lots of pics!
     
    #5 Dan, Aug 21, 2011
    Last edited: Aug 21, 2011
  6. happyvalley

    happyvalley New Member

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    What he said.

    I cringe when the first question I get asked is: "how fast will it go?". My stock answers are something like, 'fast enough', 'faster than I can pedal' and my recent favorite to that question is 'fast enough to whiz past most gas stations @ 125 mpg' ;-)
     
  7. mapbike

    mapbike Active Member

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    Just wanted to ring in here and say that Dan hit the nail on the head on everything he mentioned.

    I say go with the asiest set up you can handle, which based on what you said here is gonna be a KIT of some type.

    Any inframe set up will require a good assortment of tools and the skill to do a small amount of fabrication ( Normally needed for fitting of mounts of some type ), and some basic mechanical skills.


    Click on this link bicycle engine kit, bike engine, bicycle engine, bicycle motor and check out the kits Duane offers here, he gives great customer service and any one of these kits would be a great place to start at getting into the MB-in Hobby.

    There are other great vendors here as well who offer excellent customer service and products like Pirate Cycles, SBP...

    I say get the LARGE ENGINE stuff out of your mind and just focus on a simple easy to built set up that will get you riding asap and then as you learn from your experiences on that first build, you can build on what you've learned in the future and pursue bigger and better things if you wish.

    Duane (ThatsDax) has one of the best friction drive set ups I have seen bar none, and that would be a great way to start out, a couple hours of tinkering and you should be zipping up the road at 25+ MPH


    PACKAGE DEAL ! SUPER TITAN XC50S WITH TANK, FRICTION
    DRIVE SYSTEM, THROTTLE PACKAGE, EVERYTHING YOU NEED
    AND 90 DAY WARRANTY ONLY 392.97 AND 19USD SHIPPING !!



    This would be a great place to start, if you dont mind a friction set up.... very simple reliable set up.

    Or if you have the skills and the tools go with the inframe kit and then buy oe of his Titan 4 strokes for it.

    4 Stroke In frame Adaptor Kit with 3 piece Crank. Everything but the
    engine. Fits Titan, Super Titan, 142F, and more. Gear Box is 3:1 with
    10T mini free wheel. Only $199.99. 90 day Warranty on Gear box.



    TITAN XC50S
    $229.99
    and $19.00
    shipping
    90 DAY
    WARRANTY


    Peace, map


     
    #7 mapbike, Aug 21, 2011
    Last edited: Aug 22, 2011
  8. kevyleven007

    kevyleven007 Active Member

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    yeah,that sounds like good advice.It seems to me like most motors are going to be too wide or long for a bike like that.If you could fit an 80cc with a manual 5 speed in there that would be pretty wicked!
     
  9. kevyleven007

    kevyleven007 Active Member

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    good luck with it
     
    #9 kevyleven007, Aug 21, 2011
    Last edited: Aug 21, 2011
  10. 2door

    2door Moderator
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    The fact that too many people seem to loose focus of is that we're dealing with a bicycle. It has a bicycle's frame, wheels, brakes and was never designed to be engine driven. Keeping the power to a reasonable level, under 3hp is a good number to start with, would be prudent for anyone new to the hobby and not familiar with riding a bike or a motorcycle, for that matter.

    I agree with Al; when the first question I see from a new builder is "How can I get more power/make it go faster?" I cringe and back away from offering advice other than this:

    Build your first bike for the mechanical experience and concentrate on reliability. As the engine accrues more milage and is properly broken in it will naturally produce more power and probably and eventually all the power and speed you'll need for a bicycle.
    That's just my common sense approach and advice to a new builder.
    Tom
     
  11. happyvalley

    happyvalley New Member

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    And darned good advice it is, all around.
     

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