Monday, November 24, 2008
Make it yourself chain tensioner
Check this out. A Deore XT rear derailler with a derailler cable end (ferrule still intact) holding it in the appropriate position to act as a single speed cable tensioner. It was on a cross bike which may explain the extreme spring tension being used (since those bikes get a lot of bumping action at speed).
This would be a great way to cheapen up your old bike -> single speed conversion. I'm sure any derailler would work.
1) Find a derailler nobody wants (probably easy if said derailler is a 7 speed or 8 speed model)
2) Mount derailler to frame
3) Cut the last 4 inches off a derailler cable you were going to throw out anyway because it's roached
4) Pull the derailler to the right position (upper jockey wheel under your single sprocket) and have an indefatigable person or zip tie hold it there.
5) Install the cable with the ferrule in the derailler adjuster barrel (turned out half way) and the cut end under the clamp screw
6) Have the indefatigable person let go, or cut the cable tie
7) Turn the adjuster barrel in or out to get that jockey wheel lined up just right with the sprocket
8) Thread your chain and pull the ends together such that you get the desired tension (remember, you can always start loose and cut some off)
9) Remove the unnecessary links with a chain pin tool
10) Use a SRAM Power Link* to put the chain back together
*awesome piece of kit