33cc Bike Build - Advice needed

Discussion in '4-Stroke Engines' started by Gus PDX, Mar 13, 2012.

  1. Gus PDX

    Gus PDX New Member

    I am looking to do a bicycle build with a friend. Both of us are motorcycle guys, and can tool around pretty well. Here's what the purpose is and what we are thinking. Maybe you guys can help :)
    My friend has a small store and would like to ride it back and forth to work. Because its Oregon, it needs to be 33cc or less so that there is no need for licensing, titling and insurance. Also, he'd like to be able to put a 18x12 box on the back to transport work stuff between the house and shop. Also, this way one of his employees can use it also. Price does come into play, but its not the end all. He doesn't mind spending money for quality.

    Strength- We want to make sure that the bike is strong enough to handle the stress of an engine. I know that Huffy, Schwinn, etc that are sold at department stores are all pieces of **** now made in China. But, I took a look at some "next step" bikes at a local shop and they looked sturdier. We kind of have our eyes on a Felt 1903 and a Felt Heritage. But, are they acceptable? I know they are also made in China, but seem like good quality for the money ($400-$500)

    Engine - We are thinking about using a 4-stroke Honda GX35. Not really interested in a 2-cycle. Hondas are notoriously dependable.

    Q: Remove gas tank if I use external one?
    Q: What is the best exhaust for balance between power and noise?

    Drivetrain - Here's where I'm stuck. I have been reading the board here a lot, but I am still not sure. I AM sure we don't want friction drive. Mainly because it would take up room where the box would go but also for slip when wet.
    Aesthetically, maybe a belt drive would look better with the bike. What about using the Nuvinci?

    Can someone walk me thru connectors between the motor and the back wheel? I am not opposed to using a kit but would like to use the Honda motor.

    Thanks for your help

  2. bigoilbob

    bigoilbob Member

    Nuvinci/GX35 Feedback

    I'm still cleaning up my BikeE2 Nuvinci Developer's Kit/Gx-35 build, but my drive train is working fine. So, here's a couple of tips. The 360 hubs are probably not strong enough. The 171 hubs seem to be strong enough, but you will have difficulty shifting up manually under power (and you will want that capability). You WILL be able to shift up a GX-35, even geared down, with the Developer's kit. But you need lots of steady electric power to your transmission controller. Over 12 volts and 4-5 amps. That means either a manly battery that you are willing to recharge every hour, or a complete charging system with a little motorcycle battery. I went with the latter. I have what I want, for a cost acceptable to me. I (finally!) have none of the transmission sticking and "safe mode" problems reported elsewhere, which I think resulted from finally getting proper power to the system. But it was a pain to install using trial and error. I will post pix and narrative soon. I am ashamed to do so now because the bike still has an unfinished look (due to having to work outdoors). Once again I need to thank Loquin for getting me on the right track.
  3. Happy Valley

    Happy Valley Active Member

    Good little engine and a couple common kit solutions for the 35 are GEEB belt and Staton gearbox, both rack mounts. For in-frame, you're more on your own and need to innovate and fab mounting and drive train solutions.
  4. If his commute is less than about 25 miles round trip and reasonably flat, an electric is the perfect commuter. If he can recharge it at work, even better. My e-bikekit.com 500Watt(nominal) rear 7 speed direct drive hub motor propels my bike at 26+mph on the flat with a 48Volt, 15ampHour Ping LiFeP04 battery(lithium-iron-phosphate with no toxic chemicals involved). The battery is in a home made wooden box mounted where a motorcycle gas tank would be, which frees up the back for a rack/box. No, it really isn't in the way there. I only need to pedal assist on the steepest hills. Keep it charged and maintenence is the same as for any pedal bike. It is quiet, dirt cheap to run, and legal most everywhere. The only real drawback is it is fairly heavy.

    I don't know how to add photos here, but you can look at a picture of it on my page, Zap the green bike.
    Last edited: Mar 15, 2012
  5. BigBlue

    BigBlue Active Member

    How about a friction drive on the front wheel? You can still mount your box on the back.

    Good Luck,

    AKA: BigBlue
  6. loquin

    loquin Active Member

    It rains a lot in Oregon, BB. I use a friction drive, and they have a lot of good points, but, working well in a wet climate isn't one of them.

    If it weren't for the engine size limit, I would suggest looking at EZM. They don't have anything off the shelf that works with the smaller engines. But, contact them - Quenton states that they are working on adapters to use 35cc class engines on their kits.

    I would also look at the Staton Axle drive kits.
    Last edited: Mar 16, 2012
  7. BigBlue

    BigBlue Active Member


    maybe a crazy idea, but how about Dax rear mount chain drive mounted on the front. A disc brake hub on front wheel with a Top Hat adapter fixed to the disc mount. Mount a sprocket to the Top Hat adapter. Chain will move with forks, so no twisting of chain. Some mountain bike style forks would help with clearance issues if any. Mountain bike forks would remove the taper. Now rain wouldn't be a problem.

    Thought through some more. Since the rear hubs are normally 135mm wide and the front are normally 100mm wide, the drive mount would have to be narrowed by 35mm. This would ensure the gearbox sprocket aligns with the wheel sprocket.

    AKA: BigBlue
    Last edited: Mar 17, 2012
  8. loquin

    loquin Active Member

    Does the DAX even fit the standard 78mm clutch & mount used on the 35cc class motors? The original poster is trying to stay legal in Oregon.

    I seem to remember seeing someone posting about a Staton drive being used this way. His inside sprocket gearbox, I believe...
    Last edited: Mar 19, 2012
  9. BigBlue

    BigBlue Active Member

    Here's the info on Dax. It states a 3" clutch which is 78mm and he uses a pocket bike engine in the install video:


    Here's some pictures of different Staton inside driven gearbox:


    Also forgot about the Staton rear axle kit. I must say, the only one that I like is the black bike:)

    The one with the baskets may fit Gus PDX needs!


    AKA: BigBlue
    Last edited: Mar 19, 2012
  10. darwin

    darwin Well-Known Member

    R/S are 33ccs exactly. Great motors they just lack the lil ooomph I like as a 48/50cc has.
  11. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi Gus PDX,

    Several of our dealers have installed the smaller 4 strokes in frame using the Q-Matic drive with great success. PM or contact me directly and I will provide you with any assistance you need in your project. In fact we can "custom" design a drive system for you if needed.

    Have fun,
  12. Gus PDX

    Gus PDX New Member

    Thanks Lee. Your website doesn't want to load for some reason....
  13. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor


    I will Private Message you with my contact information.

    Just checked website and it appears to work.

    Have fun,