New member

Discussion in 'Introduce Yourself' started by Rocketman58, Nov 6, 2008.

  1. Rocketman58

    Rocketman58 New Member

    The first motorized bike I saw was back in the gas shortage days of the 70's. I liked the idea, and filed it somewhere in the back of my brain. I recently started toying with the idea of finally building one. I typically build my bicycles from scratch. I sometimes even built wheels. I also rode motorcycles for a dozen years.

    I would like to build a motorized bike with the engine inside the main triangle (not over the back wheel). My only concern is how small a bike I can mount an engine in. I typically ride a 15" MTB frame. Would an 4 strike engine fit in this small of a frame?


  2. Mountainman

    Mountainman Active Member

    not sure about that frame fit --- but - wish to welcome you

    and once you are up and on the road -- have much fun as you

    ride that THING
  3. bluegoatwoods

    bluegoatwoods Well-Known Member

    Welcome aboard.

    I'm trying to picture a 15" MTB, but I'm coming up with nothing.

    But I managed to get a two stroke into a 24" beach cruiser. It was tight, but do-able.
    I dont' know if four strokes require more clearance, though.
  4. waylow

    waylow Member

    the 4 stroke is wider, so you'd need an extra wide crank. The 4 stroke is taller, because it has to have a valve train on top of the head. And the 4 stroke must be mounded level, because it requires oil to stay at the bottom of the crank case, so it can properly lubricate the engine.

    welcome to the board, and best of luck to you with your project. I originally wanted to do exactly what you want to do, but ended up going with a screaming 2 stroke, and Staton gear reduction box that I am going to mount over the rear wheel. then I can still have my water bottles and stuff, plus, it is more like a bicycle with an engine, than a puny wanna-be motorcycle. semantics.

    Good luck in your shenanigans, lets see some pictures when you get things together.

    P.S. there is someone who makes a 4stroke kit that mounts in the center of the frame, it comes with extra wide 1-piece cranks, mounting hardware, and drive train. I can not think of the name of the company/website at the moment. I actually ordered the kit for my cruiser, but did not realize that they were sold out, and it would be a month before I could get it. I went through some hassle, but was able to get my money back. If you want a 4 stroke engine, I would only recommend the Dax kit. It is the only kit that orients the engine with the carb to your back, as opposed to the hot exhaust side. However, I think he uses a chinese copy of the honda engine. not 100% sure about that, but it is slightly different from the Honda.
    Last edited: Nov 7, 2008