I too keep my chaintubes on my trike as chainguards. They protect my pants and the paint job. You do need to pay attention to the power side of the chain. It needs a perfectly straight line for all 3 chainrings. That means you only want to hold the tube near the idler. If you use the tube as a guide on the power side, you will wear it out pre-maturely. On the return side you can guide the chain wherever you want with minimal drag. I found one article that recommends dry chain lube (teflon) for tube'd chains to keep them clean inside. Also remember not to overtighten the zip-ties as this may cause the chain to be chocked off and cause problems.