Frame Fitting for Engine Mount

Discussion in 'Introduce Yourself' started by brujahboy2004, May 30, 2012.

  1. brujahboy2004

    brujahboy2004 New Member

    Hey my name is Brandon, I just joined the forum today, and though I don't have a motorized bike just yet, I am going to be purchasing a kit very soon.
    I felt it would be a smart move to be able to bounce ideas around with a group of people who have experience with the field. I don't think I'm too ignorant when it comes to basic mechanics, but I'm not exactly "savvy" either.

    I guess my first inquiry would be about the frame I'll be using. I own a 26" Schwinn Sidewinder mountain bike (S2600WMG) that I will be using as a donor bike. It has a pretty robust frame for a dept. store bike, which was the second factor in my purchase (after budget). I heard horror stories about frames coming apart and people getting seriously injured, so I made sure to check all of the joints and welds for bubbles, gaps, evenness, etc. The dimensions on the inside edge of the tubes measures out:

    Seat Tube - 13 1/2"

    Top Tube - 19"

    Down Tube - 22 1/2"

    I've printed out a template to make sure that it would fit in the frame, and though it's a bit snug, it should fit.
    The only thing that concerns me is that the down tube is a very thick (55mm or 2 3/16") and is an oval type shape. I'm sure there would be a way to modify it, although I'm leaning more toward a build that doesn't require altering the frame (drilling, cutting etc.) I've seen people use muffler clamps to secure the engine, and was wondering if something similar would work for me :thinking: even if the tube is over twice the size intended for the engine (it's a fat boy! lol.) Please let me know what you think would be the best plan in transforming my bike into my new toy! Thanks.

    Also, I've been seeing a whole lot of debate on which motor kit is the best to go with. I'm not so much concerned with speed as I am reliability and a quality product (there are plenty of upgrades to heighten my performance if need be). I just want to see if I can obtain a well made kit "out of the box", so to speak (all machines need maintenance and tuning) so that it makes it a bit less difficult, and frustrating ,to maintain in the first place.
    Last edited: May 31, 2012

  2. Lunardog

    Lunardog Member

    Let me forewarn you on the sidewinder. Check my profile and picture album. The sidewinder does seem to be a well constructed bike. Steel frame and shimano gearing but it presents some semi-serious mods to get a 2 stroke to fit. If you decide to go this route anyhow I may be able to assist you in some of the roadblocks you may encounter. Good luck and motor safely.
  3. brujahboy2004

    brujahboy2004 New Member

    Thank you very much! I was worried that it would be a major pain to get the engine to fit in the frame. Looks like one heck of a project. Kudos on a great job! I actually ended up opting to go for a rear mount anyway. I was thinking along the lines of something I could easily disassemble and adapt for another bike, without much modification, if I were to encounter any difficulties. I'm trying to steer away from Grubee, but budget is also a concern. I'm seriously looking at the 49cc 4 stroke available on Thank you for your input! I'll be getting my kit and putting it together in approximately a month. I'll post pictures and let everyone know how it went! Thanks again!