Hi, I'm James, I've never built before

Discussion in 'Introduce Yourself' started by Jamesey, Apr 8, 2016.

  1. Jamesey

    Jamesey New Member

    I don't know too much about bike engines, but I've started reading up on this forum recently.

    My ultimate dream is to put an engine on my recently bought Columbia Tandem bike.
    Last edited: Apr 9, 2016

  2. David Bogle

    David Bogle Member

    Does the frame have room to fit one? Or will it need to have a friction drive on the back wheel? c1b5210d935ebfff52f6d17e9d296ac9.jpg
  3. Jamesey

    Jamesey New Member

  4. bakaneko

    bakaneko Active Member

    I assume this is for two people riding. With the bigger bike and two people, you are going to really need to think about the engine cc if you don't want the motorized bike to be more of a peddle assist versus a full (~95%) engine propelled bike. I don't think a HuaSheng 49cc 4-stroke unless you have a high tooth rear sprocket will be able to propel 2 people on a tandem bike very fast.
    Timbone likes this.
  5. Jamesey

    Jamesey New Member

    I would imagine that it would mostly be me riding. It might seem like a hassle or waste to motorize a tandem if others aren't going to ride it most of the time, but I wanted the option at least to give my friends rides. I don't mind if it's not very fast with an extra person, I just want something to assist getting up hills and coasting across flat stretches. This is my first build, and it will probably be a small summer project, so don't wanna go too big with the engine. Besides, with the laws as they are, I don't really wanna think about motorcycle licensing or registration.

    That said, I'm wondering how difficult it will be to mount a frame engine on a rear rack? I think it's possible, but I certainly don't know the easiest way
  6. KCvale

    KCvale Motorized Bicycle Vendor

    I suggest a front wheel hub electric drive.
  7. Jamesey

    Jamesey New Member

    Any particular models or brands?
  8. bakaneko

    bakaneko Active Member

    I do not recommend this for a first build and you will need to really plan it all out (sketches, almost everything designed) before ordering anything, but I think it is possible to rear mount the HuaSheng 49cc. I might make a rear mounted bike for my mother on a very small women's bike.

    A few impediments... you will need to get the gas tank (1/3 gallon) that mounts on top of the motor or a 4-stroke motor that is able to draw gas from beneath the carburetor placement. I think KCVale has a few of these tanks if you message him he might be able to provide or sell you one. The other thing is that you will need to buy a longer bike cable for the throttle or connect two together. Also, the rear mount rack will need to be pretty strong. I am looking at your bike and you don't have the traditional rear rack mount bar above the wheel so it will have to be a seat tube based or get the adapter (this will weaken the rack). You will have to reinforce the rack to the frame of the bike; I mean really reinforce it, which means perhaps some welding or inventive mcguyvering.

    KC suggested a front wheel hub electric motor; you will need atleast 1KW, which last I checked is still within the law and a 15-20 aH battery. This is the most sane solution but costly as the kit will be $200-250 and battery $400-500.

    * edited for 20ah not 10ah...
  9. Jamesey

    Jamesey New Member

    I know I'm not exactly making it easy on myself for my first project, but it's really what I want to do at the moment.
    As far as fixing the frame mounted engine to a rack, any idea if there are any racks pre-made for such a purpose before I go thinking about
    mcguyvering one?
    Also why would the gas tank need to be on top?
  10. bakaneko

    bakaneko Active Member

    I don't think there is a pre-made rear rack specifically designed for a rear rack mounted engine that isn't a friction drive. There are 4 mounting bolts on the bottom of the 49cc HuaSheng 142-F where you can use a metal plate to bolt onto a rear rack bike frame. I really like the bikes with a in-frame rear rack - they are really sturdy. I have a $10 rear rack that is currently holding a second 3L gas tank. It is securely bolted to my bike with high quality hex bolts and double nutted with stop washers. But, you can shake the rack and the bike will not shake. With the in-frame rear racks, when I shake the rack the bike shakes. This is what you want to replicate in terms of strength and quality of the rear rack for the engine.

    On the HuaSheng 142-F, the gas is gravity fed into the carburetor so the tank peacock has to be above the gas intake valve.

    Also, if you do get the engine on there you will have to have it running all the time even if you are peddling. It will be on idle. There is a minor resistance from the motor. Basically, what I am saying is that once you convert your bike to a motorized bike you will probably have the motor on either idling or running all the time.

    And, I don't think friction drive is bad at all. I've seen some impressive speed videos. And, you can truly operate your bike without the motor by just disengaging the roller. You can't say that for almost any other kit out there. The only issue I see is that most of the friction kits use that bolt hole across the bar over the back wheel that you are missing, but something can probably be done to adapt it to your bike.
  11. Jamesey

    Jamesey New Member

    hm, thanks. I'll look more into friction drive. I guess I would just have to remove my rear fender.
  12. bakaneko

    bakaneko Active Member

    Yeah, lol. You will have to remove it for both the rear rack mounted engine and friction drive.
  13. Jamesey

    Jamesey New Member

    Yeah, I figured that vertical support would get in the way.

    You suggested earlier that I consider getting a more powerful motor. My understanding is that anything 50cc+ is considered a motorcycle. Do the people that put, say, 80cc motors on their bikes just ride them on private property? Do people just risk it on the roads? Or do they go out and get them registered? I'm sure it varies, but what tends to be the norm?
  14. bakaneko

    bakaneko Active Member

    Take a look at this. This guy is using a modded GP460 45.7cc engine with a Staton friction drive and I can tell you he is zooming and it's impressive for a friction drive. Not saying you gonna reach this level with your bike but it is something to strive for once you have the base system up and running well.

    Well, the motorized bicycle laws depend on your state. Before you do anything probably should double check everything. Here in Wisconsin it is anything that can propel a 180lb person up to 30mph so it can be pretty much anything, LOL. I went almost 40mph today and I really don't think cops care. The 80cc 2-stroke motor kits are really 66cc and you can't tell them apart from the 49cc kits so the difficulty of proving that it is above 50cc probably helps those guys.

    I think a lot of folks just start with something simple like the HuaSheng engines and mod them for more utilization of power. And, next season, if they want something beefier they would have had the experience of operating and maintaining a basic HuaSheng to be able to do so.