Chains help with chain coming off rear sprocket

Discussion in 'Transmission / Drivetrain' started by tkrocks2, Apr 22, 2013.

  1. tkrocks2

    tkrocks2 New Member

    I bought my first bicycle engine kit and my chain keeps popping off thee rear sprocket here is what I have tried so far

    make sure the chain was running in a stright line

    flipped the rear sprocket over

    also made sure the engine was stright and tight

    I have done everything I can think of and it still pops off I don't know what else I can try.

    The only thing I can think of is I fliped the rear sprocket over when the engine was not stright and I think that might be my problem I am not sure because the chain is running in a stright line. $T2eC16F,!zoE9s5nc3tvBRdDulTmwg~~48_20[1].jpg

    Any help would be great.

  2. crassius

    crassius Well-Known Member

    in that pic, your chain has too much slack

    when tightening the chain, always roll the bike thru a full turn of the back wheel to find where it is tightest before adjusting it

    when adjusting the chain, be sure the tensioner is feeding the chain straight onto the rear sprocket rather than off to the side a bit
  3. battman29er

    battman29er New Member

    Lookin at the pic.. the chain is too loose...
    You only need 1/4" to 1/2" play...
    Also double check the tensioner is aligned
    Mine was pulling the chain off... good luck
  4. tkrocks2

    tkrocks2 New Member

    I have the chain as tight as I can possibly get it I might be able to get it tighter if I move the chain tensioner back closer to the rear sprocket.
  5. crassius

    crassius Well-Known Member

    don't do that as you're as far back as you really want to go with one of these

    take out a link and if that is too short, put in a half-link
  6. Big Red

    Big Red Active Member


    You can move the tensioner left or right to help keep the chain rolling straight on the sprocket. Also, If ya look close, The roller itself is NOT in a straight line to the rear sprocket. The V frame always puts the roller in a position thats NOT in line with the engine sprocket and the rear sprocket. If ya look at the chain, it starts on one side of the roller and ends up on the other side as it comes off. I ALWAYS, ALWAYS... twist the tensioner bar so the roller lines up. A big pair of vice grips will do the J.O.B.
    And when ya think ya got it close, roll the bike forward a few feet, then look at the rear sprocket. You can see which side of the sprocket the chain wants to go to. It should ride in the center of the chain, so when you push it side to side, the chain should have some space on both sides on the sprocket. If not, Push the tensioner VERY LITTLE to the side you need untill it hits center after pushing the bike forward a few feet.Your chain should now stay on.
    (This is all assuming your engine/sprocket alignment is right.)
    Big Red.
    Last edited: Apr 23, 2013
  7. tkrocks2

    tkrocks2 New Member

    I have found the problem my rear sprocket it bent to F**k I never noticed it until tonight I moved the chain tensioner back I got the chain as tight as I could leaveing some slack in the chain.

    I flipped the bike onto the seat and handle bars. I turned the pedals then it popped off but then I see the problem the chain gear pulls off to one side way to far witch causes the chain to pop off.

    I don't have the money to replace the chain gear I spent $197.75 with tax buying the kit and it has been a pain in my a** ever since. I think the big problem is it did not come with the instrucions to help put it to gether.

    I am just going to try and sell it the way it is I am tired of working on it I always end up getting pi**ed off at it My Honda is a better bike then this piece of junk kit.
    Last edited: Apr 23, 2013
  8. Big Red

    Big Red Active Member

    I have a Honda, I have a car and I have three personal 2 stroke bikes in my garage, Along with up to 4 or 5 customer bikes waiting to be fixed at any given time. So having other transportation is no reason to give up. They are PROJECTS, Not always just plug and play like your Honda.
    Putting one of these together takes some mechanical ability and sometimes a little patience. If you don't have one you will need more of the other. And if you have neither then perhaps building a 40mph bicycle is not for you.
    Part of the building experience is learning and part is enjoying what you're doing. It seems to me you don't enjoy building things and learning how to MAKE something work.
    So, If you're that eager to give it up over a $20 part, then again, Perhaps the Motorized Bicycle thing aint your thing. Just jump on that bad a** Honda and RIDE.
    Good luck to you brother.
    Big Red.
  9. tkrocks2

    tkrocks2 New Member

    I stopped working on it for a few days then I took a look at it today I found out that my bicycle chain is to short and the rear wheel sits right on the edge of the drop outs and when you put tension on the engine drive chain the back wheel would come out and make slack in the chain and pop off so I took off the bicycle chain and moved the rear wheel to the center of the drop outs now when I move the bike the drive chain dose not pop off!

    If you look at the picture you can see what I am mean.
  10. Big Red

    Big Red Active Member

    Glad to hear ya didn't give up on it. Sometimes just taking a break from things can help. It seems the pic didn't make it, but I know exactly what yer talking about. I always try to set the axle all the way back into the dropouts. I figure anywhere in the dropouts is fine for a peddle bike, but it's not REALLY a bicycle anymore, is it? You're gonna be doing anywhere from 30 to 45mph on it. And when I hit a pothole at 35mph I want to know that the axle isn't gonna slip and dump my a** on the asphalt.
    On a mountain bike this is not usually a problem. But I do a lot of Cruiser builds and it is a problem. The peddle chain is never long enough to let the axle sit back. I do this a few different ways. Usually I just install an old derailleur after adding enough peddle chain. But I've also used half links and a second tensioner on the peddle chain side.
    I guess I just like the idea of my axle sitting as solid as possible in the dropouts. Heres how I did it on my Baby.
    Big Red.

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  11. tkrocks2

    tkrocks2 New Member

    I would also like to try and add a moped rear rim so then I can have better way to put my sprocket on and then I can also have drum brakes witch is way better then having the bicycle v-brakes but I don't think an old moped rim would fit on the back of a bicycle.
  12. Big Red

    Big Red Active Member

    My riding partner Ocho Ninja put a moped hub on his 4 stroke build. It looks real freaking good. I'll try to remember to get pics and maybe have him contact you and shoot ya a little advice on the subject.
    I'm using the Howard Hub Adapter on the Huffy (Hussy) It works well but yer right, Drum brakes are better than V-brakes. And Disc brakes are better yet. My opinion has always been that if you can't go, you can't die. But if you can't stop you WILL die.
    Big Red.
  13. tkrocks2

    tkrocks2 New Member

    drum break

    Any pictures or advice on putting a moped rim on my bicycle would be great.

    I have never owned a bike with disc brakes I have always had drum brakes I am 19 and I have owned 70's moped right up to a 2001 tomos moped all have drum brakes even my 2009 honda 50cc scooter has drum brakes I have never had aproblem with drum not even in the rain/mud.

    I tend to abuse the mopeds I can't use a 50cc dirt bike in the city and they don't make a 50cc dirt bike in an adult size so the moped kind of becomes a street legal dirt bike then I wonder why I can't get more then a summer out of a moped.
  14. Big Red

    Big Red Active Member

    Moped hub

    I talked to Ocho Ninja and he has a thread about it on the "OTHER" forum. But basicly he says ya gotta find a moped hub that fits between your dropouts,(Maybe with a "little" stretching.) Get a steel rim with the same number of spoke holes that can be drilled for the bigger spokes and build yer wheel.
    He said Sportsman sells the hubs, but I think they are overpriced on EVERYTHING.
    Anyway, here the link to his thread. Hope it helps.
    Big Red.

    I just looked at his thread and it don't go into the hub build. I'll chew his a** out and make him get hold of you if yer still interested.

    (P.S. If you wanna look me up, I go by fatdaddy on this forum.)