Question about clutch types

Discussion in 'Frame Mounted Engines' started by nms, Apr 19, 2007.

  1. nms

    nms Guest

    Hello all, first post here

    I recently decided that I want to try my hand at adding a small engine to a bicycle. I intend to do this from scratch - no kits. The point is not so much to get it done easily, as learn as much as possible and create a completely custom machine. As things currently stand I'm planning to use a small (~30 cc) weed eater engine.

    I've done a little research, and from what I can tell most people on here use a clutch that is very similar to an automobile one. I've seen several links to the one on kings motor bikes . com (separated because I'm not allowed to post URLs). I've also seen several posts about those clutches wearing out or burning up.

    I was planning on using a centrifugal clutch instead, mainly because I assumed that was the norm, and for simplicity.

    What are your thoughts on the kingsmotorbikes clutch vs centrifugal ones?


  2. Hugemoth

    Hugemoth Guest

    I prefer the manual clutches like the Chinese engines use because you can disengage them at speed to coast.

  3. Guest

    Guest Guest

    Totally your preference.
    A centrifugal clutch will simplify things greatly- no cable/lever/ect. Cheap and easy to switch out or adjust too.
  4. TheBadBunny

    TheBadBunny Guest

    Goofy newbie question about centrifugal clutches

    I'm almost embarrassed to ask what I'm sure is a stupid question, but I know nothing about engines. (In fact, one of the reasons I'm looking forward to getting a bicycle engoine is to learn a little about them). Can you pedal start an engine with a centrifugal clutch, or do you have to :yuck: pull start it, and is it still possible to disengage the engine completely so you can pedal with no drag?

    And if it's a manual clutch, can you have hand brakes on both handlebars and still have room for the clutch lever?

    The reason I'm asking this is because I want my motorized bike to stay as close to legal as possible and still have all the features I want. Here in Georgia, they are considered mopeds and must not require clutching (except to start) or shifting. However, I DON'T want a pull start, and as I'm an avid cyclist, I want to be able to pedal freely most of the time. I intend to use the engine mainly to make my commute to work quicker.

  5. Alaskavan

    Alaskavan Guest

    No pedal starting with a centrifugal.
  6. mopedjay

    mopedjay Guest

    you can pedal start it with a centrifugal clutch if you have something to lock up the clutch when starting most mopeds work like this

    then theres clutches like motobecane mopeds have where the clutch has 2 sets of shoes one set of shoes engage at a lower rpm so when you pedal it engages the engine and starts
  7. mnbiker

    mnbiker Guest

    Cent. clutches use g-foreces to engage. As the motor spins faster the shoes expand allowing grip on the out casing with the sproket on it. They do not create alot of drag if motor is not running. So i would think you could pedal normally with not much more friction. You could always lube the outer and the inner part(shoes) to allow them to spin easier.