chain falling off issue.

Discussion in 'Frame Mounted Engines' started by mikesova, Oct 18, 2008.

  1. mikesova

    mikesova Member

    I'm having an issue w/ my chain coming off. I can ride it all over town and not have a problem... or I can go take off and hit a bump or brake hard and it will come off. Today I had the clutch locked with the lock and got off the bike and the clutch activated and caused the chain to fly off and roll around off the sprocket. Shouldn't it just stall in that case? Would the idle being adjusted to high cause that to happen instead of it just stalling? I'm not sure what the deal is, I figured it would be an alignment issue, but it looks pretty straight, any ideas?

  2. bluegoatwoods

    bluegoatwoods Well-Known Member

    If I understood your post right, then it sounds as though your chain just isn't tight enough. That would seem to be the case if merely engaging the clutch caused it to slip off.
  3. mikesova

    mikesova Member

    nope, it's plenty tight. it's really weird.
  4. MotorMac

    MotorMac Member


    Your sprocket is probably not in alignment. Check your rear sprocket by spinning the rear wheel ,and see if its wobbling ,a 1/8th to 1/2 inch wobble will throw the chain.You may need to take a peice of chalk or a marker and hold it against the sprocket turning the wheel the marker will hit the high spots.
    Last edited: Oct 18, 2008
  5. Mountainman

    Mountainman Active Member

    if you get down real close to the chain and sprocket

    spin your drive unit very slowly

    look to see EXACTLY where the teeth of sprocket hit in the chain

    should hit directly in middle of chain --- sometimes easier said than done

    if chain sides touch much to one side of sprocket - adjust as needed

    ride that thing
  6. Knol

    Knol New Member

    Sometimes when a chain gets thrown at high speed it will bend and take a set as it wraps or unwraps itself from and into unintendended components. If your chain seems to rock left and right as it runs from the rear to front sprocket this could be part of the problem, and even if the thing that caused the problem the first time is fixed, the damaged chain would still be with you. I think MT.MAN is right about chain alignment on the sprocket being important, also the idler could be acting as a deraliuer if it is more than slightly out of square or off-center under load assuming the obvious (sprockets are true, the engine and rearaxle bolts are tight and the frame isn't broken)
  7. HI,

    You may want to bevel the sprockets if you haven't already done that yet.

    Hope this helps you.

  8. fetor56

    fetor56 Guest

    It sounds like an alignment issue....maybe even try a different brand of chain known to fit perfectly(KMC K910 Xtreme Freestyle)