My first build, chain problems

Discussion in 'Frame Mounted Engines' started by senorpyz, Jun 3, 2009.

  1. senorpyz

    senorpyz New Member

    I finally got my kit from thatsdax.com and mounted it on a Schwinn Del Mar. The bike was less than favorable for putting the kit on, but with some adjustments I got it mounted. I have managed to completely get rid of the chain tensioner because it was causing the chain to derail. However, the chain is still coming off. What are some possible reasons for it falling off?

    (the chain tensioner is still on in the pictures)
     

    Attached Files:


  2. AdamT

    AdamT Member

    Are you sere the back sprocket is lined up with the gear? if not maybe you can angle the tire so it feeds and recieves chain at tah right angle. Did you mount the back spocket perfectly. Take the chain off and spin the back wheen on a stand or a upsode down bike and see if it is true.
     
  3. BoltsMissing

    BoltsMissing Active Member

    Can you post a few close up pics on the front and rear mounting.
    By the looks from here, the front mount seems "tall".
    When you rev a car's engine, you notice the "twist" from side to side.
    That same "twist" occurs to on the HT, and it's up, or clockwise depending what side of the bike you are on.
    The point is, it may seem with the pics provided, the front mount being "tall" is bending on take off, and causing a slight miss-allignment ?
    I know this from my own expirience, had a rear mount "extended" on larger frame and it sheared everything right off the scales.
     
    Last edited: Jun 4, 2009
  4. Mountainman

    Mountainman Active Member

    yes good stuff there in those replies

    stand to the back of your MB -- four or five feet

    as you line everyTHING up in your eye -- all should look fairly straight

    if not -- it's a good THING to work on -- to be in aline is more than fine

    I like to ride my MB THING all the time
     
  5. brendonv

    brendonv Member

    Walk your bike and look at ur back sprocket. Make sure the chain is almost centred on the sprocket at all times, if it moves like 2mm then u need to adjust the sprocket so its centred. It may be slightly off so the chain is going from side to side and when its going around like 5 times a second it will throw it off. Thats about all it can be. Its got to be centred or it wont work. Just tighten some screws and/or loosen others to get it to be perfectly straight.
     
  6. HoughMade

    HoughMade Guest

    Also, if the rear sprocket is not centered on the hub, it will get loose and tight as the wheel spins and may cause it to come off.
     
  7. Junster

    Junster Member

    Sometimes you need to file the tips/sides of the teeth on a new kit sprocket to keep the chain from climbing on the sprocket.
     
  8. i use the tensioner to keep my chain lined up with the rear sprocket and my chain never comes off.
     
  9. sajoe

    sajoe New Member

    I had the same problem. What I finally figured is the kit chain is bent in 2"- 3" segments. Some parts are bend inward and some are bent outward. I filed my rear sprocket and that helped but the problem persisted. Today I stopped at Tractor Supply and bought a new chain. You get 10' for 16.98. I cut the chain to the same length as the kit chain (which had stretched over a 1/2 inch in less than 10 miles of riding) installed on my bike and my chain problems are over. My bike seems to have less vibrations and seems more peppy and easier to pedal. It started raining so I cut it short and will try again tomorrow. Best 17.00 I have spent in a while plus I have enough for another chain. I also got rid of the tensionor as I believer that to be a weak link.
     
  10. my chain broke and so i replaced it,im still useing the tensioner but i might take it off if i can get the chain the correct length.
     
  11. sajoe

    sajoe New Member

    I took a good ride yesterday and no problems what so ever. I made a short ride today and the chain still has the same tension as when I installed it. Needless to say I am very happy with the new chain and wish I hadn't have waited 2 weeks to get it! I did make a pair of chain adjusters which don't allow the axle to move or be pulled forward by torque.
     
  12. Claydoh

    Claydoh New Member

    How did you make the chain adjuster?
     
  13. sajoe

    sajoe New Member

    I am glad you asked. I have attached pictures. Basically I notched two small pieces of angle iron and bolted them to the fender brace bolts, the adjuster part is a washer with a threaded rod attached to it. The washer goes on the axle the threaded rod through the angle iron. When you tighten the nuts it pulls the wheel back and tightens the chain. It works really well. If I can answer further questions let me know. I had the adjusters in a box full of bike parts I don't remember what they are for but you can do the same thing as I said with 3/8" washers and 1/4 " threaded rod.
     

    Attached Files:

  14. machiasmort

    machiasmort Active Member

    Lie down on the ground and take a picture, top and bottom of your chain lines from the rear sprocket. Sorry if you did alread, I've got an important meeting.

    You don't want your chain cooming off... The bike will stop but you will keep going!!!
     
  15. Snax

    Snax Member

    Seems like one might have trouble keeping the proper tension on both sides while also keeping the wheel aligned.

    One key to making the provided tensioner work well is to use as little of the adjustment range as possible, minimizing the angle of deflection of the chain over the tensioner. I had to shorten my chain to get a proper setup. Otherwise the tensioner kept slipping.
     
  16. sajoe

    sajoe New Member

    I think with a half link on the motor chain you should be able to get close enough. On my bike the pedal chain is not real tight but I really only use it to start the motor and take off from stop signs and it is plenty tight for that. I didn't have to use the half link. If one can get rid of the tensioner they will be much happier. I know I am.
     
  17. Just_Gasit

    Just_Gasit Member

    I would agree about getting a quality chain, the one that came with my kit is junk, uneven and had a few slightly twisted sections. I also had trouble with sprocket alignment untill I realized the rubber piece I used on the sprocket side was thinner at one end, I could never have gotten that to adjust out. Seems the old tire it was made from had a flat spot. Picking up some better chain is on my "must do list" asap.
     
  18. ENO

    ENO Member

    Get a better chain

    The chinese junk chain is the problem most have with their chain and tensioner stability. I went to a chain supplier (in Australia) and took in the cheapo to have it matched..Ended up with a motor bike quality chain that does not bend side to side, is a better gauge steel. and is always stable. In Oz the company that supplies is Blackwoods in Newcastle Aust..the manufacturer is "Fenner"..The chain is a "Fenner Roller Chain" and numbered size of 415 S (S meaning motor bike grade) $13 AU for a ten foot length which is two chains and then buy yourself ten chain links for around 33 cents each. Bingo..end of chain breaks and probs
     
  19. Just_Gasit

    Just_Gasit Member

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