nlreid44

Hello, Im in the procees of an Engineering Project for my Engineering Design and Development class. I'm looking for information on bicycle derailling correctors. Does the technology already exist to where if a chain slips off track that a mechanism will put the chain back on track without the rider having to change gears or completely stop the bike? Any information is well appreciated.

jgedwa

A couple of things out there that do something like this:

-the derailleurs themselves are their own "correctors" I suppose.
-Bashguards on the front ring keep the chain from going too far over or under.
-Paul and, I think, Rohlhoff make something like a dummy front derailleur cage that keeps the chain from slipping of the rings
-N-stop and some others make a little clamp on projection that keeps the chain from dumping off the inside of the front chain.
-and a whole bunch of various things that downhill MTBers use to keep the chain from bobbing around.
-good ol' dork disks keep the chain from overshifting into the spokes on the rear.
-on singlespeed setups I have seen a specialty cog that has a small flange on both sides of the cog that keeps the chain from wanting to go somewhere else.

Not to say that there is not room for another solution, but as it stands there are several ways to keep the chain from being where you don't want it to be.

jim

SmallieBiggs

On a bike with derailleurs, if they are properly set up, having the chain fal off is actually quite rare. If the chain does fall off the front chainrings, and the bike still has some forward momentum, you can often shift the chain back onto the chainring.

For bikes without derailleurs, or bikes with only rear derailleurs, there are a few devices available - rear cogs with guides built in, devices that bolt near the front chainrings to physically block the chain from faling off, and bash guards are all options.

nlreid44

Yes i have seen the derailleurs and other devices such as this, but these only appear to prevent the slips, none that i have seen really correct the problem without causing further hassle

jsharr

There are devices to help keep the chain from gettting sucked into areas where it should not when it does come off the front chainrings. Google anti chain suck devices for more info. Most experienced riders can get the chain back on the front rings just using the shifter as previously noted. Not sure anything else is really needed, but would be interested in seeing what you come up with.