This project is meant to solve bike chain lashing when riding offroad. Generally, in such situations, chain jumps out and you will know it just when you will push on pedals again in the need of traction :( I designed this item passing through several improvements, releases and tests on the field. This is the last release; the one I considered fully working. I have been using it on a Cannondale Rize 120, but I guess it will fit many other different bikes. Now my new bike has chain tensioner as a standard equipment, but I would be pleased to know if my creature fits your bike too ;-) In my several re-productions I used PLA at different layer thickness. Because of the destination use of this item, extruding at a very low thickness value is just a waste of time. Please try at 0,2 mm layers before other values. Once printed, you will need to take supports away, probably using a small screwdriver. In addition to printed parts, you will need: