Anybody know of a chainwatcher that bolts to the front derr.

I have seen a few people that have made them, but I don't know of any manufacturers that sell them. I believe they are usually a custom made piece... shouldn't be to hard to make if you know how to wield or have a friend that does.

I believe they are usually made to work with a braze on derailleur.

These don't bolt to the derailleur, but sit down by the inner chainring to keep the chain from dropping.

https://cyclocrossworld.stores.yahoo.net/chainrings.html (top of the page)

Or am I massively confused as to what you're looking for?

dog fang?

That was my 1st thought.

I don't get why anyone uses these things. Shouldn't your chain stay on if your derailleur is properly adjusted?

Should.

Seems pie-plate-esque to me.

Yeah, I don't use them.

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.

i think 'crossers use them on single-chainring bikes

so how effective are these dog fang things? Can someone say that since they put one on they've not dropped the chain?

I'm thinking of getting one if it is reliable

All that tells me is that you havn't worked on enough bikes yet.

Look - even the pros use them, and they've got mechanics making sure everything on their bikes is in tip-top shape before every race, every stage.
Chain drop happens most often when climbing, when you downshift from the big-ring to an inner-ring, whether double/compact/triple, and are simultaneously putting a lot of force in your pedal stroke.

It's common. Get over it.

They are not used as often by people who don't climb.... and let's not bring up yet another f'ing banter about how some people claim they have "climbs" when they are in fact just oversized speed bumps. Come out to California, Colorado, for example in the US, and get some real climbs.

I'm not a bike mechanic. I work on my bikes and they don't drop chains.

I don't shift under force either but I can see how that would induce chain dropping.

They work well. The problem is that they only fit on round tubes of typical road bike size. So if you have a modern carbon masterpiece with a flared seat tube or a square one, the dog fang won't fit. Some pros run custom chain watchers made of steel or aluminum that bolt on to the front derailleur hanger. But so far no one makes them for sale that I have found, they are all custom work.

Yes. Dropped the chain a few times before installing the Dog Fang and not in the 10,000 km since.

thanks guys,sorry but that was my first post.I saw one on someones bike and thought it was a good idea.As it turns out i really cant ride,my bike sucks and i couldnt tune it even if it didnt suck.Thanks again and happy holidays to all.

I have one on my cross bike and would put one on my mtb if I could fit it around the pivots. I have not put one on my road bike yet but only because I am not racing these days so I don't often need to respond to an uphill attack (plus southeast Georgia is truely pan flat). I have dropped my chain off of the little ring and not had it slide back on or when I was running a 1x9 set up. This has only happened with heavy mud/ice/snow that gummed up the rear derailleur and/or the monitor was not lined up just right.

Everybody always shows this one, a custom chain watcher made for a pro:



https://www.bikeradar.com/news/articl...-special-15801

Nice work!

(There's a better pic of it somewhere, just not at my e-fingertips right now.)

I've thought about getting one. Sometimes I drop the chain when going from big ring to small ring and I'm already in something small on the cassette. Usually happens when I forget that I'm in the big ring, and I start downshifting the rear to start a climb, and then I go to trim the front (forgetting I'm in the big) and it'll drop right off because I don't stop pedaling because I think I'm just trimming.

When they start to come off does it hold it close enough that you can just backpedal and it will catch? Or does it keep it from coming off at all? I would be pissed if I dropped a chain in a race, so I guess I should probably get one.

w/ a dog fang, the chain falls onto the fang and the slides back onto the inner ring. you don't stop pedalling.

Dropping a chain sucks in a race, but you will probably find yourself very rarely shifting the front. this is course dependent, obviously, but I big ring pretty much all crits. In a road race you only shift down once at the bottom of a hill, and back up until you come to another hill. The pack needs to slow below ~14mph for you to HAVE to shift to the small ring. that doesn't happen often when not on a LONG climb

Well, some people have additional reasons.

For me the chain was falling off so I got the dog fang. I adjusted the FD and things were fine. Then I got an SRM. When the chain falls now, it lands on the power sensor. A $10 dog fang saves me a lot of aggravation if the alternative is a broken sensor since the cables are expensive.

thanks for the pic, I guess ill have to make one.that helps a bunch thanks