Bike Chain Guide

Got tired of my bike chain falling off when shifting into the small chainring in the front. Designed this parametric piece to attach on the lower seat tube (as seen in the photo), and stop the chain from falling off on the inside. You can customize to fit any height, seat tube diameter, and distance from the edge of the seat tube. You can also use any size screw/nut you have (within reason) using the clamp hole diameter setting. I used M3 and it is working fine, but M2, M4, M5, anything that fits on the clamp arms should work!

I measured using calipers the diameter of the seat tube, and the distance from the edge of the seat tube to about 5mm from the small chain ring. 

Recommendations: 20mm height worked well for me. 10mm cutout was a little small, recommend 15mm. 10mm clamp lengths worked well without getting in the way at all. 2.5mm wall thickness worked well as well. Feel free to play around with the parameters!