Drive train

Discussion in 'Motorized Bicycle General Discussion' started by gphil, May 13, 2014.

  1. gphil

    gphil Member

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    Worked a day and a half putting back the drive wheel etc. Have a new # 41 chain, got her all tightened down with new chain on and turned the wheel to make sure all was going well and it was great. Put on a new chain tension arm with the spring and all was well. Turned the wheel about a half of a turn and the chain came off. Tried twice and came off. All was in line off no more than 1 /8 inch . I am thinking the chain tension arm is causing it. Otherwise done. No where to turn except build a new bike using something better in drive train and bike. Sorry to complain guys just aggravating as **** . gphil
     
  2. crassius

    crassius Well-Known Member

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    sounds like you may need some spacing washers to set your tensioner wheel in line with the chain
     
  3. gphil

    gphil Member

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    I am thinking along the same lines. All seemed good until I put that thing on. I sure hope you are correct, otherwise stumped. Not to mention seems like time wasted. gphil
     
  4. 2door

    2door Moderator
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    I'm not a fan of spring tensioners for several reasons. However, any tensioner you use must be installed so that the tensioner wheel is aligned with the chain path. The kit clamp-on fasteners are notorious for being out of alignment with the center line of the chain and all typically require the mount be bent, or twisted to align the wheel with the chain or it will tend to pull the chain off to one side causing chain derailment.

    Whatever tensioner you choose to use, make certain that it only applies pressure to the chain to maintain tension, and not drag the chain off to either side. Contrary to popular belief, tensioners are not meant to 'guide' the chain. If the drive and driven sprockets are properly aligned there is no reason to guide the chain, but only to keep it tensioned. 1/2" to 3/4" of slack is what you want.
    Spring tensioners will allow the chain to go slack on deceleration. That you don't need or want.

    Tom
     
  5. gphil

    gphil Member

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    To be honest I did not check on that alignment. 90 degrees in the shed and looked good, if you know what I mean. Prior reading this post, I did go back and it rides towards the wheel. When I installed the spring type I was not real thrilled , just was a hassle and just in general had made mind up to take it off, too tight etc. So I agree with all said and is appreciated. Hate to be a pest. Thanks for all the info from all here. I will let ya know how it works out. Guess I could jack shaft it but that involves other expenses..... gotta love it I guess. gphil
     
  6. maniac57

    maniac57 Old, Fat, and still faster than you

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    One good way to double check alignment is to spin the wheel in BOTH directions. If it spins free without any chain popping or noise even backwards, it is good.
    I ALWAYS have to add a twist to the stock tensioner bracket to get it properly alugned with the chain. I use a huge crescent to carefully twist it.
    I agree with 2door about not being a fan of springs, but if you DO use one, it must still be straight.
     
  7. mapbike

    mapbike Active Member

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    Spring tensioners only work if properly lined with already properly lined chain between drive and driven sprockets and the chain must be basically adjusted so it would still work if tensioner wasn't there, the springing down action is a bad thing as Tom mentioned unless the cchain is adjusted so that it can only slack about 1/2 - 3/4" and then all the tensioner is doing is keeping that small amount of slack out when your under throttle.

    The only set up I ever tried that gave me fits and headaches was trying to run a spring tensioner, I chunked it and went with an adjustable tensioner/idler set up or none at all and all my problems have been solved, no more chain issues.
    Map
     
  8. gphil

    gphil Member

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    Well you guys convinced me. Nice cloudy day so going out and do away with the spring tensioner. As mentioned, did not like it shortly after installation. So will see later on. Thanks. gphil
     
  9. gphil

    gphil Member

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    Went to shed, beat that damned spring tensioner off, put back the adjustable one and walla, all is well. I did hear two pops as the new chain went around the engine pulley but that was all. Feel so much better. Thanks all around for all the help, suggestions that came from the crew here on this site. Really appreciated. Got fingers crossed for you know these little suckers. gphil
     
  10. mapbike

    mapbike Active Member

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    Great news gphil, glad you're up and running without issue.

    It could be that the #41 chain being as wide as it is wa catching a bit on the housing cover over the drive sprocket, I know that even with running the KMC415H chain it hits and rubs a little in there, some people do a bit of grinding in the area where you will see it has been rubbing when the cover is removed so that is stops hitting in that area, since its aluminum and has never caused me any problem I just let the chain wher it down in that area the way it wants and dont worry about it, not the best method I know but it has never created any issues for me, the #41 chain is even bigger and wider than the 415H chain so it could be that the chain was binding just a little as it passed an area on the cover that it was rubbing on, in a short time that area will be worn down and thn it wont bind there anymore if that is what happened.

    Ride safe and enjoy...

    dnut
    map
     

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