What the broken chain rollers is going on here!?

Discussion in 'Frame Mounted Engines' started by Fletch, Feb 14, 2011.

  1. Fletch

    Fletch Member

    Check out these pics of my chain. I just noticed last night that MANY chain rollers were completely missing from my chain! That can't be good lol. There are some broken rollers on their way out in the pics too.

    So what is causing this?

    My theory is that it is either:

    A) Just a crappy stock chain that went bad after 350 miles (doubt this one because of the severity of damage)

    B) Sprocket is eating the chain up on at least a couple teeth. If I roll chain backwards it pops on sprocket. I thought this was bad alignment, then realized it was just on a couple teeth and only when the chain moves backwards (which is strange). Forward movement and riding is perfectly smooth. No popping or chain jumping?

    C) I had a fairly loose spring tensioner which allowed for whipping of the chain. The whipping action caused this somehow. I'm switching to the stock tensioner now.

    What do you guys think? If it is the sprocket teeth on the wheel, what should I look for (ie. what do I do?). I've been known to go nuts with a dremel so I don't want to guess at it. (It just now occurred to me that it may be the drive sprocket as well?)

    It's the stock 415 chain....


    Attached Files:

  2. spad4me

    spad4me Member

    Replace the stock junk chain with a number 41 chain from Tractor supply, Lowes, Ace hardware.
    You wont miss the old one at all.

    The stock 415 chains are junk
  3. motorpsycho

    motorpsycho Active Member

    The reason why the chain skips on the sprocket when you roll it backwards only is because the teeth on the sprocket are worn in a pattern from the chain going the correct way. Reverse the chain rotation and the pattern wil be different, causing the chain to want to jump off the teeth.

    I don't think the stock 415 chains are junk (at least mine aren't).
    You do have to take the time and lube each individual link when the chain is brand new, and make sure that there are no tight links before you use the chain.
    Lubing the chain every once in awhile also helps.

    I think that maybe your sprocket and chain are not perfectly in line, and that's what's causing the rollers to come apart....altho i could be wrong.
    Last edited: Feb 15, 2011
  4. Fletch

    Fletch Member

    It actually skipped on the sprocket (backwards) when the sprocket was new. Honestly I think it is low quality sprocket that wasn't machined well. It was only $14 (dax).I just put a new 415 on and lubed it well. I do notice that the chain has worn the sprocket. The is like a lip on the edge of each tooth now. I could probably grind it smooth.
  5. V 35

    V 35 Member

    I agree with the ' low quality sprocket ' theory, and would suggest a better made one.

    Are you correctly indexed ? An off index sprocket could pound chain.
  6. Fletch

    Fletch Member

    I'm not sure what you mean by indexed?
  7. V 35

    V 35 Member

    Indexed = Set truly perpendecular to axle. No high or low spots. A true wheel would have the tire * indexed * to axle. Careful measurement is required to index a rag joint sprocket, an out of index sprocket would have a camshaft effect on the chain.
  8. HeadSmess

    HeadSmess Well-Known Member

    stock chains are junk.

    only chain ive ever had that snapped through the plate!

    heavy duty bmx chain is still holding up for me after quite some time... and, oh so smooth! except at certain rpm when it resonates n flaps around!!!!!!

    then you replace your sprocket with a good one from a bmx or similar. a real bike sprocket, not cheap punched sheet metal piece of scrap... mark out and drill holes, there you are...
    Last edited: Feb 24, 2011
  9. RdKryton

    RdKryton Active Member

    The sprockets must be aligned properly or the chain will suffer. That will also make the chain climb off the rear sprocket when rolling the bike backwards.

  10. Fletch

    Fletch Member


    Yeah I really think that it was a case of not lubing the chain with the right stuff in the beginning, and then cleaning it by soaking it in gas and or solvent, combined with the sprocket teeth being imperfect as evidenced by the indentations the chain made. I think the 1st chain "broke in" the sprocket, so hopefully this second chain won't suffer the same fate ;)

    What is best for cleaning the chain while still on the bike? Just a rag? Damp? Is degreaser ok? I've read WD-40?
  11. V 35

    V 35 Member

    I like Carburator or brake cleaner, use outdoors, flamible, can damage plastic, for very
    dirty parts. For moderate grime, a stiff brush and some Automotive spray cleaner
    [ refillable pump bottle ] and a later blast with very hot water. Be careful around graphics, either cleaner can damage them.

    Simple Green is gentle to fine plastics, while not the most aggressive, removes
    milder greases. Oil up with detergent motor oil to soften grease, than wash.
  12. Fletch

    Fletch Member

    Awesome, thanks! I bought some carb cleaner before and that stuff shot out of the can in a jet stream! It was hard to be accurate with it (I was aiming at spots to test air leaks.

    If you use the carb cleaner, should you rinse with water before re-lubing, or does it matter? It's mainly dirt and not grease I need to get off the chain.

    As far as plastics go, I can't think of any around the chain area.

    If you hose down the bike with water like a car, outside out the air filter is there any areas to avoid? It would be nice if you could stick your bike in an automatic car wash ;)
  13. Dave C

    Dave C Member

    Plus use real motocross chain lube. It's made to stay on and work under the worse conditions, racing on dirt. I'm useing Dumonde TECH BHP Chain Lubrication & O Ring Conditioner. It doesn't say what BHP is but it goes on kind of like a gel then like soaks in.. all I know is it's the best chain lube I've tried :p
  14. Fletch

    Fletch Member

    I actually do use motorcycle chain lube now (not sure the name), but I was trying that dry teflon stuff from Lowes because someone said it was good. It wasn't enough lube for me. the chain runs much smoother with the motorcycle stuff. It's like you describe; sticky and soaks in.