is my chain to high on the back sprocket

Discussion in 'Motorized Bicycle General Discussion' started by cj200, May 27, 2012.

  1. cj200

    cj200 New Member

    Joined:
    May 19, 2012
    Messages:
    27
    Likes Received:
    0
    is my chain to high on the back sprocket at the top point


    here some new pic "you can click on them"

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]
     
    #1 cj200, May 27, 2012
    Last edited: May 28, 2012
  2. Al.Fisherman

    Al.Fisherman New Member

    Joined:
    Sep 9, 2009
    Messages:
    1,966
    Likes Received:
    1
    Hard to tell, as the pictures could be better, but, it doesn't look like the chain sits down far enough.
    Did you bevel the teeth on the sprocket (both sides)?
     
  3. cj200

    cj200 New Member

    Joined:
    May 19, 2012
    Messages:
    27
    Likes Received:
    0
    what do you mean by bevel the teeth on the sprocket
    sorry im new to this

    here some new pic "you can click on them"

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]
     
  4. Nashville Kat

    Nashville Kat Active Member

    Joined:
    Apr 20, 2009
    Messages:
    1,436
    Likes Received:
    3
    I would say yes, the angle on the tensioner is too great. You should level that out as much as you can while still maintaining chain clearance of the frame stays. You may have to take out a link or two, which can be a daunting task if you haven't any experience at it- and you need a decent chain cutting tool.

    Are you having some kind of problem? You still have a lot of dropout left if you want to pull the wheel back- that will level out the chain a bit, but the idea is to chain the angle with the chain tensioner the least you can get away with. You may have to adjust the brake pads then.

    I don't know about the beveling suggestion- Is that for a smaller 410 chain? I don't know what chain you have- most common is 415 and the sprock shouldn't need any special grinding. The sprocket is often countersunk on one side- make sure you're getting the benefit of allignment and frame clearance with the countersunk on the most appropriate side for your build. It appears you have the countersunk facing so you get the moist frame clearance, which is good- IF you are getting good allignment of the motor and wheel sprockets.

    Here's a tip for the long run- a smaller sprocket helps give you not only a faster top end, and less noise and less revving in the midrange, it also helps frame clearance issues by making a smaller arc for the chain- Unless you are very heavy or riding a lot of mountains or off road.

    I never use a chain tensioner on my cruiser fframes with 34, 36 and 39 sprockets- your Mountain bike frame may have less clearnce and a smaller sprocket might relieve any clearance issues. Your motor is pretty high on the frame and appears it may be sitting at a bit of an angle- but the back mounting looks square to the frame- if you could get the motor sprocket lower I think it would help, but then you may have other chain clearance issues.

    If you are going to ride primarily on the road, you may want to get some smoother tires- those knobbys will give you a lot of vibration at speed. I 'd recommend 26 x 1.5 or 1.75 to give a great roll and weigh less.
     

    Attached Files:

    #4 Nashville Kat, May 28, 2012
    Last edited: May 28, 2012
  5. cj200

    cj200 New Member

    Joined:
    May 19, 2012
    Messages:
    27
    Likes Received:
    0
    ok thank i took out as many links as i could but it still is kinda lose, yes the problem is the chain comes off the
    sprocket and jams when comeing down hill or when hitting a bump. i try puting the tire back farer but it makes it hit frame them
    i have this
    BIKE KIT Link
    kit on my bike and yes it is a Standard 415 Chain,

    thanks for the tips. i wants used everyday there hill where i lives lots of them lol but im going to get a smaller sprocket ; what would the best sprocket to used be a 36 sprocket?.

    i can put the motor sprocket lower again but the chain comes lose and i cant remove any more links form it.
    but im going try it later today and see how it work out.

    thank you for the help.
     
  6. donphantasmo

    donphantasmo Member

    Joined:
    Oct 3, 2010
    Messages:
    360
    Likes Received:
    0
    You want a little bit of play in the chain. I don't mean an inch, I mean a quarter inch, maybe 3/8. So, you can move the tensioner back and forth, up and down to achieve the desired tension.
     
  7. Al.Fisherman

    Al.Fisherman New Member

    Joined:
    Sep 9, 2009
    Messages:
    1,966
    Likes Received:
    1
    Sometimes the teeth on the sprocket are too square on the ends. To correct this, take a file or some kind of grinder and slightly file/grind off the sharp tooth edges. This will let the sprocket follow the chain and seat better on the sprocket.
     
  8. wayne z

    wayne z New Member

    Joined:
    Dec 5, 2010
    Messages:
    1,746
    Likes Received:
    0
    Your chain and tensioner position look fine.
    Is the tensioner accuratly aligned both lateraly and linearly? Have you put a little twist in the tensioner bracket to get the idler wheel aligned(this is the linear adjustment) with chain ? If not, that's prolly what's throwing your chain.
     
  9. cj200

    cj200 New Member

    Joined:
    May 19, 2012
    Messages:
    27
    Likes Received:
    0
    no, i never did that but i will try later.

    thanks for the help everyone, ill post if i gets it to work.
     
  10. biknut

    biknut Active Member

    Joined:
    Sep 28, 2010
    Messages:
    6,378
    Likes Received:
    5
    Your biggest problem is your chain tensioner is sitting there thinking about moving to a new location, next door in spokeville.

    If I were you I'd redesign your tensioner. I would never use the stock tensioner the way you are. It's just begging for trouble.
     
  11. Al.Fisherman

    Al.Fisherman New Member

    Joined:
    Sep 9, 2009
    Messages:
    1,966
    Likes Received:
    1
    Also, it appears that the chain is not laying in the sprocket as it should. Hard to tell as it might be a discolored sprocket.
     

    Attached Files:

  12. cj200

    cj200 New Member

    Joined:
    May 19, 2012
    Messages:
    27
    Likes Received:
    0
    i move the motor down and the chain and it still isn't laying in the sprocket fully
     
  13. Nashville Kat

    Nashville Kat Active Member

    Joined:
    Apr 20, 2009
    Messages:
    1,436
    Likes Received:
    3
    Sounds like an allignment problem then, assuming there are no manufacturing defects.

    It could be the chain side to side, or else the ragjoint isn't holding the sprockin line, or the tensioner is messing with the chain allignment. Check all three.

    If it's a chain allignment problem- maybe turning the dish of the sprock around would work better- you just have to sight it all from behind- or you can add spacers or washers sometimes to the wheel axle and get a slight bit of side to side allignment that way.

    NOW THAT I'VE LOOKED MORE CLOSELY- it does appear that you have the dish of the sprocket turned the wrong way out. (There is no real right or wrong way when trying to achieve allignment, but it USUALLY goes the other way to give greater frame clearance. If the frame clearance disappeared from simply pulling the wheel back- that's probably why. turn the sprocket so that the teeth are farther AWAY from the frame and closer to the spokes- the best chain allignment is usually achieved this way as well. Look at the chain from the back, and you can use a straight edge to see if it's straight if you want.

    also make sure the motor itself is mounted straight on the frame- if the motor leans- and sometimes it can pull itself to the side- the motor sprocket can angle off center right off the bat.
     
    #13 Nashville Kat, May 28, 2012
    Last edited: May 28, 2012
  14. rustycase

    rustycase Gutter Rider

    Joined:
    May 26, 2011
    Messages:
    2,746
    Likes Received:
    0
    lol

    I will assume there ARE manufacturing defects with the sprocket AND the chain !

    Spin the back wheel and dress the sides of the sprocket with a coarse file like Alf says...
    NOT a lot, just a bit to help it find its way, until things wear in a bit.

    and replace the chain with a real one!

    and of course, make sure the rag joint is holding the sprocket true, both concentric and side to side wobble...

    The tensioner doesn't look as shakey as some I've seen, like Wayne said... just check that it's running true and not holding the chain off one way or the other.

    You've got an evil combination going on here... lol
    ...a rag joint
    ...a china sprocket
    ...a stock chain
    ...and a tensioner

    Whew!

    ..nothing that can't be sorted out, though.

    Best
    rc
     
  15. tooljunkie

    tooljunkie Member

    Joined:
    Apr 4, 2012
    Messages:
    663
    Likes Received:
    0
    i put a straightedge on the plate part of the big sprocket,and make sure the motor sprocket is close to in line with big sprocket.
    i also stand above rear wheel and look straight down on chain,with bike straight ,chain should be in line also.i noticed my tensioner was not centered so i bent bracket to make chain roll in middle of tensioner wheel.

    when i installed sprocket,i pulled wheel off,put parts on loose,re-installed wheel
    and spun wheel around and tightened sprocket bolts evenly.(bike upside-down )

    if motor can be moved at all in frame,in any direction,chain can derail.
    i welded my brackets to the frame.
     
  16. Nashville Kat

    Nashville Kat Active Member

    Joined:
    Apr 20, 2009
    Messages:
    1,436
    Likes Received:
    3
    I still say it's a chain allignment problem and that probably you need to turn the sprocket around- and make sure it's true as well.

    The other possibility not discussed is that maybe they shipped the wrong chain?- I can't see the width in these pictures- could it possibly be a 410 chain- is the box marked? And probably not if any poirtion of the chain is seating correctly-

    so partially seating? Chain allignmentside to side.

    then the last thing I would do is any grinding- believe me- I think the dish is turned out the wrong way- the chain should be offset TOWARD the spokes. Probably line right up then.
     
  17. Nashville Kat

    Nashville Kat Active Member

    Joined:
    Apr 20, 2009
    Messages:
    1,436
    Likes Received:
    3
    here is the usual correct installation of the sprocket, as far as the offset "dish" is concerned- unless the allignment might require the other way. This 41 kit sprocket I had bolted to this flip/flop hub. It has since been changed to an alloy 39. This mounting eliminates the rather heavy ragjoint too. Use titanium bolts and an alloy sporocket and you have it weighing next to nothing.
     

    Attached Files:

    #17 Nashville Kat, May 29, 2012
    Last edited: May 29, 2012
  18. cj200

    cj200 New Member

    Joined:
    May 19, 2012
    Messages:
    27
    Likes Received:
    0
  19. cj200

    cj200 New Member

    Joined:
    May 19, 2012
    Messages:
    27
    Likes Received:
    0
    i turn the sprocket around and make sure it's true as i could.

    the tensioner seems to be working good now a little loud but good,i had add a piece to the tensioner bar to keep the tensioner wheel for moveing down

    i was out on it for passed 2days on off and i travel a nice ways to day and it diden come off or seem like it was going to.

    but im still a little bit afraid it may happen again

    i add some more pic of what i did



    [​IMG] [​IMG] [​IMG]

    [​IMG]
     
  20. cj200

    cj200 New Member

    Joined:
    May 19, 2012
    Messages:
    27
    Likes Received:
    0

Share This Page