Chain Tensioner Would like some help with my chain idler issue! Thanks guys!

Discussion in 'Transmission / Drivetrain' started by Donavan321, Jan 8, 2013.

  1. Donavan321

    Donavan321 Member

    Okay, so I've built over 30 of these motorized bikes and they're awesome! I ran into a new problem however....I JUST finished my motorized scwhinn 26" cruiser, and my chain tensioner/idler likes to dive over close to the spokes Im worried that one of these times ill be oing half throttle and it will catch and wreck everything including me! If I were to drill a hole through the tensioner and into the frame and use a screw or bolt, would this keep it in line? I have pictured my cruiser here. I'm broke so I can't buy a different tensioner :p so..what can I do to make this one work?
     

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  2. jefuchs

    jefuchs Member

    I'm a newbie here, but I've read that you should drill a hole so that you can put a screw through the mount, and into the bike frame, keeping it in the upright position.
     
  3. sawdust

    sawdust Member

    just my 2 cents worth..I would take a piece of flat bar..put a hole in one end and attach it to your idler then have the other end going to the front of the bike and use a u clamp to go around the lower frame bar(the same one that your chain tensioner is attached to) so that it makes a triangle. It will keep the tensioner from moving forward since now it has support in front of it. It's something I thought I might need to do to my bike..but then I put tape under my tensioner and used grade 8 bolts and nuts and really tightened mine tight..it hasn't moved yet and this is on a tandem with two guys on it on some pretty steep hills here.
     
    Last edited: Jan 8, 2013
  4. sawdust

    sawdust Member

    oh yeah..unless you want your frame to crack and brake..do not drill any holes in your bike frame anywhere..just ask around here..or rather read other posts...bad things will happen if you do
     
  5. johncy7

    johncy7 Member

    Best dirt cheap tensioner you could ask for

    When I came up with this I was sure someone would wish they saw it. Lucky you!
    Here's what you do: (after studying the pic)

    http://www.motoredbikes.com/attachment.php?attachmentid=47288&stc=1&d=13576980 17

    * Attach one of those curved pieces of metal bar from a sprocket assembly (or something similar) to your idler wheel. (don't tighten all the way because this needs to slide up and down)
    * Drill an extra hole if necessary into the metal bar. (this is important for allowing the tensioner to move down but also to prevent it from moving too far down)
    * Drill a small hole through the idler and frame and insert a small nail. (hole should be same size as the nail)
    * Attach a bungee cord to the metal bar and the bottom of the bike seat.

    You'll have to fight the urge to laugh or listen to any negative comments. This tensioner is flawless and has given me zero problems. Sorry about the small pic, this system keeps chopping it down to 32kb.

    Note: I use a cheap super glue on all my threads as a loctite. Never had a problem yet.
    Anyone selling this of course must pay me royalties!

    -John
     
  6. Samdallas214

    Samdallas214 Member

     
  7. Samdallas214

    Samdallas214 Member

    O what I was going to post
    my chain tensioner would move/come un-tighten loose I solved it by just rapping a piece of old inner tub around the frame used lock washers and that fixed mine has not moved in over 3 months and hundreds of miles and no drilling into your frame
     
  8. johncy7

    johncy7 Member

     
  9. Samdallas214

    Samdallas214 Member

    When I click on it I keep getting this message

    vBulletin Message
    Invalid Attachment specified. If you followed a valid link, please notify the administrator

     
  10. johncy7

    johncy7 Member

    let me try the inline attachment option...

    tensioner.jpg
     
  11. Samdallas214

    Samdallas214 Member

    Now that's a he!! of a way to do it if it works is all that matters learn something new every day
     
  12. Greg58

    Greg58 Member

    One thing some members do is drill and tap a hole on the outside of the mount for a set screw, if you use a set screw with the locking teeth it will stay in place. This way you don't weaken the frame.
     
  13. Donavan321

    Donavan321 Member

    Thanks guys! I decided just to wrap duct tape around the frame where the idler mounts I wrapped and wrapped and it seems to work good, as soon as I can, I will probably try to go for some kind of spring loaded tensioner! Any good cheap recommendations? Bikeberry? SBP?
     
  14. Fabian

    Fabian Well-Known Member

    How i wished that SickBikeParts would engineer left and right side chain tensioners for their shift kit, so you don't have to spend time making them yourself.

    Until it happens, it's D.I.Y
     
  15. Donavan321

    Donavan321 Member

    Yeah that's true. Well I did find a few spring loaded tensioners on bike-berry but of course they're OUT OF STOCK >.> I'm hoping I can come up with something soon.
     
  16. Samdallas214

    Samdallas214 Member

    Ebay has them not so cheap though around $40.00USD

    http://www.ebay.com/itm/SPRING-LOAD...444?pt=LH_DefaultDomain_0&hash=item4d086bb5ec

    http://www.ebay.com/itm/Spring-Chai...Cycling_Parts_Accessories&hash=item484ed6e5d1

    http://www.ebay.com/itm/SPRING-LOAD...pt=AU_Sport_Cycling_Bikes&hash=item35c33443c7

    http://www.ebay.com/itm/motorized-b...uty-rollers-MADE-USA-/230909791314#vi-content
     
    Last edited: Jan 10, 2013
  17. Samdallas214

    Samdallas214 Member

  18. jefuchs

    jefuchs Member

    That first eBay item looks like more of a DIY project than something you'd want to buy. The standard bike setup already comes with most of those parts. Just add a pivot arm and a spring and you can have it made and operating in a day, rather than wait a week for one to be delivered.

    The last ebay link, with the plate that mounts to the motor, is a great idea. What would be better would be a re-designed clutch plate that does the same thing. Then it would look like the motor was designed with a tensioner from the beginning, which maybe it should have been.

    Here's another one -- basically the same idea. But most of their stuff is out of stock.

    http://boostbottleindustries.com/motorized_bicycle_chain_tensioner.html
     
  19. Samdallas214

    Samdallas214 Member

    I just post them If it was me I would just make one , but other would rather spend the $40.00.
    I thank the home made one is far better and cheaper I bet.
     
  20. Samdallas214

    Samdallas214 Member

    how about this one
    a more for a minibike but might work
    http://www.ebay.com/itm/CHAIN-TENSI...Parts_Accessories&hash=item1c281a77fe&vxp=mtr
     
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