Chain Guide, ala PVD
The need for a chain guide
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 consumable parts

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.
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The parts included in the spares.
The custom clamp
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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.


