Announcement

Collapse
No announcement yet.

Chain tensioner for road bike

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Chain tensioner for road bike

    Hi All,

    Just wondering, after fitting my 3rd chain recently(to a vtr 250), why bikes dont have chain tensioners. I have a front and rear sprocket spare, couldnt i fit the front sprocket to a piece of bar that attaches to the swing arm to tension the slack (or slack there of) chain. I know there is only about 1inch to 2inch of free up and down action but if the tensioner was on some kind of spring wouldnt this prolong the life of the chain and also aid in smoother power during acceleration and deceleration.

    Any feedback/past experiences be much appreciated

  • #2
    Most modern bikes have chain tensioners mate. I know mine does, and just about every modern'ish bike ive seen has them. They should be at the end of the swingarm and there should be like a 10mm bolt that you can tighten and loosen which will adjust the chain tension.
    ZippySig.com

    Comment


    • #3
      But that is a manual way of doing it, I want one that tensions the belt in the front of a falcon but for a chain...

      Comment


      • #4
        You mean like a spring loaded tensioner that keeps the chain tensioned at all times but if needed it can untension itself using the spring?

        Is that what you mean?
        ZippySig.com

        Comment


        • #5
          Yeah something that hangs off the swing arm, like on some of those mountain bikes.

          Comment


          • #6
            The reason the mountain bikes have those tensioners is because the chain tends to jump off the sprockets when you are doing jumps and landing hard etc. Motorbikes dont have that issue, unless the chain is really really loose on a motorbike, the chain wont slip off the sprockets. Thats why its important to have the chain at a good tension. A chain tensioner would not work on a motorbike because unlike a bicycle it does not have a free wheel hub which spins freely when power is disengaged.
            ZippySig.com

            Comment


            • #7
              But wouldnt it help in taking off and slowing, by taking any slack from the chain. Also reduce the yanks in the chain when doing so

              Comment


              • #8
                No, because when your accelerating, the top of the chain is tensioned as the front sprocket is pulling the rear causing the wheel to spin. When you are decelerating, the bottom of the chain is tensioned as the rear wheel is slowing down quicker then the front sprocket. So putting a chain tensioner on that would be quite useless i think. But i may be wrong.
                ZippySig.com

                Comment


                • #9
                  But in between these movements is when it yanks at the other direction, so if i could minimize this then the chain wouldn't get jerked all the time. Not that Im going backwards that much but like when you sit at the traffic lights and the chain goes slack...actually now that i think of it, if chain tension serves it should stop the teeth on the sprockets from opening up from chain stretch.

                  Comment


                  • #10
                    Rather than extra arms would it not be simpler if you wanted to do this is put a set of springs in the swing arm pushing the rear axel towards the rear maybe with a basic preload adjuster to adjust the actual tension. Some sort of over centre way to disengauge the springs for working on the rear wheel would be a good idea too. You could just go buy a shaft or belt drive bike once you've finished the 250 thing.
                    Harvey community radio has a motorcycling show listen over the web here www.harveycommunityradio.com.au ,Facebook here http://www.facebook.com/pages/The-Mo...34691323302991 yes I am the goose that hosts it.

                    Comment


                    • #11
                      while it would work it would be of no benifit as there is not enough slack in the chain to accomodate this. notice how much the belt of a falcon changes direction around the tensioner pully. also the the belt trying to tighten against the pully would straighten the chain and load up the pully spring to much.

                      Its been said before. the companys spent millions on developing systems to work eficiantly, im sure they would have thought of this.

                      Then again make somthing up and test it out. buy another vtr and employ the system one one and swap between the two every day, see if you get a better result on one.
                      IM ALWAYS ON THE EDGE, ITS ONLY THE SHARPNESS THAT VARYS

                      Comment


                      • #12
                        Spring loaded chain tensioners used to be in every motorbike shop in the 70's and early 80's. Nearly everyone had one on their MX bike as the countershaft sprockets were a fair distance from the swingarm pivot which caused a lot of variation in length between the CS centreline and the rear axle centreline. When long travel suspension came along bikes were throwing chains left, right and centre and the tensioner was the only thing that would keep it on.

                        There were a few around on road bikes but I guess they never really took off and have mostly been forgotten about.

                        Fitting one certainly won't harm anything and will reduce the number of times that you have to check and adjust your chain. It could even extend the life of your chain if you were the kind of person who might be likely to forget to check it regularly.

                        But then again, it is only a 2 minute job to check and a 5 minute job to adjust a chain.

                        Comment


                        • #13
                          Had one on my YZ 125 E. Worked ok.
                          "It moved"

                          Comment


                          • #14
                            Are you replacing the sprockets when you do the chain?
                            Posted via Mobile Device

                            Comment


                            • #15
                              We are missing the point here...3 chains on a 250 in how long? Why?

                              Comment

                              Working...
                              X