Chain Tensioner My Chain tensioner! Can someone please try recreating this and making it work better?

Discussion in 'Transmission / Drivetrain' started by Donavan321, Jan 14, 2013.

  1. Donavan321

    Donavan321 Member

    I decided to build a spring loaded tensioner and it worked pretty good but i couldn't figure out a good pivot bearing and it worked pretty good then stopped working Ill mess with it more tomorrow :( Thanks guys.

    Attached Files:

  2. Fabian

    Fabian Well-Known Member

    Is it just me looking at things wrongly, but your chain tensioner appears to be set up on the wrong side of the chain.
  3. V 35

    V 35 Member

    A agree with Fabian, the tensioner belongs on the * slack * side of the chain. You have it set up so it has to fight engine torque .

    As far as the pivot, the bolt may loosen, a left hand thread bolt may tighten under load. Hurst Shifters [ car 4 speeds ] use
    a replaceable bushing, another source is car door hinge repair kits . Use grade 5 or 8 washers, as the slotted hole may expand
    with use. To me, the best tensioner is one that can't wind up in the spokes.
  4. Donavan321

    Donavan321 Member

    I agree, and I've built several of these bikes I intentionally set this up the way it was, I know how it's SUPPOSED to be, I just thought I'd change it up a little to see how it would work. I have taken it all off so I can make one that will push "up" on the chain instead of How I have it now.
  5. V 35

    V 35 Member

    I found that the bike handled better when chain tensioner is on slack side . When I tried pushing the chain tight, reactive torque
    reared its ugly head, the bike was a [ female dog ] to pedal, and you almost had to ride side saddle to go straight.

    So here I am, spent a bunch of time and money on an ill handling beast that Wonder Warthog would have a hard time pedaling,.
    the torque of a slot car, the noise of a chainsaw, man what a bumber ! Gave up for couple days, tried no tensioner, scared me,
    but the bike went straight, and pedaled easier . Wound up creating my [ not recommended ] gusseted idler, which used a piece
    of 1" x 1/8 " steel strapping brazed to rear wheelstays, and a second piece bolted to gusset. The tension roller lifts the chain,
    a light spring provides some pull . Thought I was so smart ! Bolt loosened on a long ride, roller met spokes, not a recommended
    way to go. Fastening tensioner to seat post [ ahead of wheel ] is inefficent, but safer . I currently use a piece of slotted strapping,
    brazed parallel with chainpath to support roller . If there is a fubar like a roller bearing shredding, the roller flopping around, hitting
    the spokes, would be hit downward, and away from the spokes. A spring loaded ' lift ' draws roller into spokes.
  6. Donavan321

    Donavan321 Member

    I haven't had any problems yet at all with mine. I know those guys love playing in the spokes. But I think the reason they go in the spokes is from the torque of the drive chain so it "pulls" the tensioner into the spokes! I have found that since I added my spring mechanism the idler is flush and straight and far out from the spokes, since I have done this it hasn't even budged from where I've put it!
    Last edited: Jan 16, 2013
  7. wally

    wally Member

    No it is misaligned the rear sprocket front sprocket chain tensioner and mounting point of the tensioner must all be in a straight line. It is no good for the tensioner bracket to lean over because it will be pulled into the spokes I have never had a problem with the stock tensioner, then again I don't do 20 miles at a time only approx 3 miles.
  8. Donavan321

    Donavan321 Member

    All of my stuff is aligned as should be, I haven't had any problems with the stock tensioners either but in my experience, each bike is different, different bikes run into different problems. My bike was brand new from the factory and the wheels are true as can be but I had to reverse the sprocket, and the chain did fine. My idler however was the stock and it leaned in towards the spokes asking fro trouble, even bent one a little and I've never had this problem until now, AND I REEF on the nuts and bolts as well. I added the spring tensioner idea and have not had a single mishap, been riding everywhere and STILL perfectly straight. THEY really DO work...well for me at least. A tensioner that likes playing in the spokes would become a rider's killer.
  9. Stoltzee

    Stoltzee Member

    After multiple attempts at lining the rear sprocket with the front I used a piece of string down the center of the chain, and it was off. Stand back and look at it. I used an old sprocket as a shim, and I've been running it with way too much slack in the chain for months. It hasn't come off, but it's time to get a better tensioner.
  10. crassius

    crassius Well-Known Member

    getting the rear sprocket to line up with the front sprocket isn't all that important since the engine will pull it into line pretty well - the important part is getting the tensioner to feed the slack side of the chain as straight as possible onto the bottom of the rear sprocket - I always grind the sides of the teeth at the top 1/8inch to make them very pointy so that they will find the center of the chain without letting the flats of the chain ride up over the sprocket