pic: Floating Zip Tie Chain Tensioner

[JesseK]

This is a fantastic and simple idea! Now let's hope they don't ban zip ties... We would want #25 chains, but probably only 1.25" in length because we have some short chain runs to deal with from the transmissions.

Have you done any efficiency experiments, e.g. how much efficiency is lost due to these tensioners when compared other methods? Examples include autotensioning (sliding a wheel out like 254/968/etc), simple rotary tensioners that use delrin or similar plastics, or the old adjustable bolt/sprocket method.

If you find that there's more loss (due to increased contact surfact area) you could experiment with teflon or oil-impregnated plastic surfaces. Also, you could change the geometry in the channel itself to be curved convex rather than simply flat. This is how the secondary tensioners on Harley Davidson motorcycles work -- turn a bolt and a convex-curved piece of teflon raises against the chain to fine-tune the tension.

< edit >
Another thing you could do is create a working relationship with a company such as AndyMark or a local plastics mold company, who can mass-produce these for teams and give your team a % of the revenue. The upside to this is that it should be low-stress supplemental revenue for your team. The downside to this is that you miss producing and selling these yourselves, which opens up a whole new can of worms in opportunities for more people from your community to learn and participate in your program.

Food for thought.
< /edit >