Chain Guide, ala PVD

By running a single front ring on my six speed MTB, I have to have a way of keeping the chain on the ring. Without a guide, the chain will fall off several times a ride.

Since I ride trails, I wanted a nice solid chain guide that didn't mount in a heavy way to a bash guard. Chainrings are the only bash guard a singletrack rider needs.



The Truvative Boxguide box is available as a spare part for about $20. It's a good idea to design around cheap and commonly available consumables.

This is the stock configuration of the part.





The parts included in the spares.



The print for making the clamp and mount bracket. It's not a production drawing, so it's a little sloppy with some details left for other prints.


I machined a custom bracket to mount the box to my frame from the seat tube. Locating the proper position of the guide was the most difficult part, but a little math helped.



It's a super solid set-up.



139 grams. Not the lightest, but tougher than anything you can find.







Pretty slick!