The Catrike Clamp-On Return Idler Kit comes with a return side idler (either Sport or Elite) and, like the power, a Clamp-On Idler Mount, all necessary chain keeper hardware needed to float a return idler anywhere on a Catrike that you'd like. Most people put their floating return idler just in front of the right side frame tube. Depending on boom position and chainring sizes, the idler can handle the chain going over or under. It can take some serious finagling to get just right, but for those people looking to eliminate chaintube, this kit can be a big help.
This is exactly the part needed to get rid of the chain tubes on a Catrike 700.
On my Dumont it works great and got rid of all chain tubes. On my wifes' Villager the best position was still not perfect. When shes on the big chainring it would rub the bar under the idler causing a lot of friction. A double wheel would work, but I simply removed the bar and luckily the chain goes right into the idler when necessary