I was on a really hard group ride when I changed down too quickly and threw my chain all the way off the front chain ring. As I saw the group vanishing away from me at about 40 km/h I knew that was me for the night. Blast. It was even worse when I shifted back up again to try and get my chain back on the chainring: it somehow got wrapped around the crank arm so I had to dismount and manually fix everything. Talk about a newbie error.
Even though I meticulously maintain my bike, problems like this do happen. I did some research and found out about ‘Chain Catchers’. These attach to your bike and stop the chain from going off the small chain ring.
You can buy them for about ten dollars at places like www.probikekit.com – here is link to the ones they carry. The problem is that these only fit on round tube frames and so would not work on my Cervelo P3 which needs a derailleur mount. I bought a couple for my road bike thought. Another option is to make your own as described in the excellent RBR newsletter.
However, if your pockets are deep and you want one which will look great, check out the K-edge. These are beautifully engineered titanium catchers which mount on the derailleur. This is a photo of one that I lifted from their site, hope they don’t mind.
It is very easy to install and you don’t (usually) need the ‘Hard to Fit’ kit. All you do is remove the derailleur bolt, replace it with the K-edge, line it up with the small chain ring and tighten. In the six months I’ve used it I’ve not thrown a chain.
They come in Gunmetal, Red, Blue, Black and Gold, weighing only 10 grams (if you are that fanatical). If you do a search at www.froogle.com for ‘K-Edge Chain Catcher’ you’ll find them for about $34. Small price to pay for security. And great looks!