Spring Loaded Chain Tensioner – Installation

May 2, 2005 - Courtesy Misfit Psycles Inc.

1) This tensioning device (hereby referred to as Thingy) is designed and intended to take up (minor) chain slack as a result of chain stretch and/or the result of gear ratio/chain stay differences. It is intended to eliminate chain skipping and drive train damage as a result of a slacked chain. This tensioner will not take the place of a derailleur nor will it be able to pick up the slack of poor (initial) chain set-up.

2) The Thingy is attached to the derailleur hanger. As a result that derailleur must be removed…

3) There is a pin on the back of the Thingy that will be placed ‘behind’ or ‘aft’ or ‘rear’ of the hanger. Once it is attached, this pin (in conjunction with the spring that hopefully you cannot see) that will create the tension required to hold the chain taunt.

4) Ensure that the pin is in position and tighten the Thingy in place. It is possible to bend, crush, and destroy that poor pin so take it easy. And tight so it doesn’t fall out, not tight so the arm doesn’t move.

5) Prepare the chain. As with all spring loaded tensioning devices this Thingy works best (strongest) at the highest point of tension. In this case the highest point of tension is up towards the chain stay. The easiest way to achieve this high level of tension is to marry and have children. You should also use a chain length as close to ‘natural’ as possible. 

6) Ignore the Thingy at this stage, run the chain on both cogs and select a length that is the shortest possible. Break the chain at that point. Chances are the chain length will be ½ to 1 link too long (thus the need for a tensioner).

7) Remove the chain from the cogs and route it through the Thingy. Through the guide and over the roller. Using the allen key move the pulley arm in or out to estimate the straightest chain line possible. Off the cogs you should have enough slack to assemble the chain easily. Put the chain back on the cogs. 

8) If for some reason the chain is not long enough to roll back on the cogs add one link at a time until it does.

9) Using the allen key move the pulley arm in or out to ensure the straightest chain line possible, if you didn’t get it right in step 7.

10) Now complete the chain should appear almost ‘normal’ with only a minor ‘dip’ at the Thingy. If the chain sags and the Thingy is pushing well below a ‘normal’ chain line, you have a problem. Go back to step 3, do not pass go do not collect $200.

11) Ride.