Originally Posted by
liquefied
I don't get why anyone uses these things. Shouldn't your chain stay on if your derailleur is properly adjusted?
We use one on our Tandem. With a triple chainring, and the forces involved with a tandem, you're a little more likely to drop a chain.
And if the chain drops, and the Captain doesn't react quite fast enough, its possible to destroy a $4,000 frame.
Not that likely, but a Dog fang at a cost of $10, and 10 grams is cheap insurance.