Cranbrook, Chain shake/flap/slap

Discussion in 'Motorized Bicycle General Discussion' started by stilldoc, Oct 17, 2009.

  1. Creative Engineering

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    stilldoc, pedal pusher:

    Remove your chain and lay it out on a flat surface. Look to see it the chain is twisted lenthwise. I've seen several new chains that were twisted. This causes a lot of problems, and the chain should not be used.

    Jim
     
  2. xlite

    xlite New Member

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    Hmmmm... I haven't run into that situation (yet). My chain is right up against the stay too and even wears a little paint off there. Fortunately I've not had to resort to a half link myself.

    I'm surprised you can't simply adjust the wheel enough. On my Magnas I did have to remove the "insert" in the right side dropout and put a bolt through the derailleur to allow more rear movement of the axle.
     
  3. xlite

    xlite New Member

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    I've seen that too and pretty bad on a couple of my chains. It didn't cause trouble though except for an occasional "tic" which went away. I wonder if you can't simply un-twist with a pair of channel locks or even a couple screwdrivers?
     
  4. BarelyAWake

    BarelyAWake New Member

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    I'm not quite sure what you mean, if you mean move the axle rearward thus adjusting tension - I don't think that's an option ;);
    [​IMG]
    (old chain/old pic, hoseclamp as chafeguard to protect aluminum chainstay - don't need it anymore & fixed tensoner)

    If you mean space the hub/sprocket to driver's right to allow more clearance for chainstay/chain - I don't really want to do that as it's in line with the engine's 10t so perfectly now...

    or... am I misunderstanding?
     
    #24 BarelyAWake, Oct 21, 2009
    Last edited: Oct 21, 2009
  5. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    I saw something that got passed over pretty much...running the sprocket against the spokes is not good and should not be done. Use a piece of leather, rubber or even felt may work (get some at Jo Anne Fabrics, walmart or where you buy your frillies from).
     
  6. BarelyAWake

    BarelyAWake New Member

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    Yeah Joe, I've seen that before - I was surprised that the spokes took it at all! o_O
     
  7. gerdesd

    gerdesd New Member

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    check your tire to make sure its not rubbing on the frame or chain
     
  8. 2door

    2door Moderator
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    Barely,
    On the previous page you said you need the chain to stretch so you can get the tension right but the photo you posted shows an adjustable tensioner. Why not just raise or lower the tensioner wheel to get what you're looking for? What am I missing?
    Tom
     
  9. BarelyAWake

    BarelyAWake New Member

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    Yeah, sorry Tom - It is an adjustable tensioner, but just not quite adjustable enough meh Everything works, I just cant put the tensoner where I want it yet.

    Without a guide my chain will hit the stays, but even so the chain would be a hair to short or way too long for that anyway - depending on where I wanted to put the master.

    With the guide to bring the chain up and back a bit, it clears the stays but I have a limited range of fore and aft movement of the guide before it's out of alignment with the sprockets, and not quite enough vertical height to take up the slack even in it's furthest reward position without getting to close to the sprocket. At it's lowest setting and all the way forward I'm back to the problem of 1/2 link too short or a link too long... "It's so almost" :p

    An interesting problem, some of it due to how high my engine is relative to the rear sprocket, some of it is the angle my chainstays have and where it puts the guide should I move it forward or back.

    When I first put the chain on, a 1/2 link would have fixed it right up and been the perfect length. I didn't have a 1/2 link and they worry me anyway (maybe unnecessarily), I figured that I'd cut it as short as I could and wait till the chain settled in and shorten it then. Currently the tensioner/guide is all the way aft and raised almost all the way, tho it works it's not ideal - doesn't matter though because I was checkin' it out a minute ago and I think I have enough to take that link out now :D

    I'll admit there's ways I could have fixed this, I have another tensioner, the other style with two mounting bolts - that one has a more vertical adjusting slot and thus more reach, but I don't think those hold as well undrilled. I could grind this one so the slot is longer, or... I could wait 50 miles or so lol I'll also admit I'm picky as heck about havin' just the right amount of slack, my last confession is I need to rid myself of that treacherous roller mount altogether and make one that spans the bars...

    edit: Wow - I rambled on o_O I suppose "There's not enough adjustment" woulda sufficed heh
     
    #29 BarelyAWake, Oct 21, 2009
    Last edited: Oct 21, 2009
  10. stilldoc

    stilldoc New Member

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    Well, the "Sprocket against spokes... baaaaaaad!" statement from Xlite bothered me so I re-mounted the sprocket using the 2nd rag joint between it and the spokes. I didn't think this would allow for the coaster brake arm to fit back over the rectangular brake cone but it did. In doing this I had to bend the brake arm to clear the bolt heads (which I finally got right after 3 attempts). And I gave up the dust cover altogether.

    I hadn't thought of checking to make sure that the direction of the tensioner wheel is parallel with the chain as Tom suggested. I'll check that, and Jim's suggestion to make sure the chain will lay flat when removed is a good idea.

    I'm not sure what you mean, Bandito, when you refer to the motor not being at 180 degrees. Are you asking whether it could be tilted a little sideways?

    I haven't got the bike put back together to try it since adding the rag joint, but I will report the result when I start it up again.

    (Do these bikes sometimes make you think of the 1979 movie "Mad Max"?)
     

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    #30 stilldoc, Oct 21, 2009
    Last edited: Oct 22, 2009
  11. freewheeling frank

    freewheeling frank New Member

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    ya guys thanks bairdco i can probably get those washers at ace hardware. i have marked the axle position with a sharpie and it is moving say 1/8 inch in maybe 15-20 miles. gonna find me some o them washers, thanks guys
     
  12. xlite

    xlite New Member

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    On most of the models I've done the axle cannot be moved all the way back because they put a small "slug" inside the right dropout to hold the derailleur from rotating. You usually can't see it w/o loosening the derailleur. Most bikes can still adjust chain tension enough (1 link) but a few needed to have that "slug" replaced by a bolt outside the dropout or else need a half link. One or the other. Anything to get rid of that dam tensioner.

    I can't take pics now but will do so when I can.
     
  13. BarelyAWake

    BarelyAWake New Member

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    Mine has vertical dropouts - so while yer right, that isn't applicable to my bike ;)
     
  14. xlite

    xlite New Member

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    Actually it's about the same (diagonal) as most but because of engine height I see the problem. No adjustment via dropout. Tuff bike. Hopefully you get that tensioner issue worked out.
     
  15. Venice Motor Bikes

    Venice Motor Bikes Custom Builder / Dealer/Los Angeles

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    I've always had clearance issues when using the 1/2 links too. I don't use them on the engine side anymore; instead I use a smaller 1/2 link on the pedaling chain. This trick doesn't work for bikes with derailleurs though...
     
  16. camlifter

    camlifter Active Member

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    i've done a few crane brooks and i know what you mean by, the sproket is up against the spokes, on the crane brook to get the sprocket lined up with the engine sprocket you leave out the outter rubber and just use the inside piece, that puts the sprocket up against the spokes. but now theres not enough clearance for the 2.125 tire and the chain will rub and jump all around, a smaller 1.75 tire works much better when only running the one rag joint. you may also need to bend the coaster brake arm to clear the sprocket bolt heads.
     
  17. bandito

    bandito New Member

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    "I'm not sure what you mean, Bandito, when you refer to the motor not being at 180 degrees. Are you asking whether it could be tilted a little sideways?"
    Stilldoc I guess a better way of saying it is to make sure your engine/gearbox sprocket is at 180 deg vertically to match your tensioner and rear sprocket.
     

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