My Chain Fell Off, What to Do?

I Was Just Riding Along…
"And I changed gears, and all of a sudden, my legs were pedaling against no resistance at all." Or, "my bicycle made this terrible noise and I looked down and the chain wasn't right," or "I took my bicycle out of the car and the chain was all messed up."

Is My Bicycle Broken?
Technically the chain should not come off your bicycle if:
You are shifting correctly.
Your derailleurs are adjusted correctly. Your bicycle is transported carefully.
Your bicycle got shifted when you weren't paying attention.
Your bike is a fixed gear single speed or internally shifted hub, with or without a coaster brake.

Shifting Correctly
Go to the Riding Tips portion of our website and read the section on "What Are All Those Gears For? Or, More Simply, Shifting Explained." Then, if you still have questions, you and your bicycle are welcome to come by the shop. We can look at your bike and make sure everything is functioning correctly and spend some time to make sure you are comfortable shifting your bike.

Bicycle Adjustments
Bicycles are really simple, but not so simple that they stay perfectly in adjustment forever. There are a number of reasons why a bicycle's drive train can come out of adjustment enough that the chain won't stay properly in place when you ride or shift the bicycle. We can perform adjustments or repairs on any bicycle. Sometimes the problem is a matter of adjusting cable tension in the drive train. Sometimes there are more serious problems. We can tell by looking at your bike and estimates are free, so if you are confident you are shifting correctly, and you are still having problems with the chain falling off, please bring your bicycle by!

I Took My Bicycle Out of the Car…
Not everyone travels enough with their bicycle to justify the purchase of a car rack. Sometimes it seems easier and cheaper to put the bike in the back seat or in the trunk, or in the back of a truck. A bike rack for your car is always a better way to transport a bicycle because it is secure and less likely to be damaged by incorrect loading. Anyway, here are two tips on how to put your bike in the car to make sure the chain doesn't get knocked around.

Always put the bike in the car, chain side up. Be careful that nothing rests on the rear derailleur or chain.

Still, even the lightest bicycle is an awkward thing to shove into the back seat of a small car and if you take both wheels off, the chain can get knocked off as well.

Did Someone Mess With My Bike?

Really, honestly, if your bike is locked up somewhere, it's not that likely that some person is going to come up and randomly shift your bicycle. Its more likely in that moving it around, putting it on a bike rack, hanging it up at home or locking it up downtown, one of the shifters got shifted without the bicycle being pedaled. It's not a terrible thing, but it can cause that chain to jump off when you jump on and pedal away.

The Chain Came Off My Kid's Bike (Or My 3 Speed, or Beach Cruiser)
This is more serious because these kinds of bicycles are fixed gear. If the chain loops over a cog on the rear hub and the single chainring in the front and you have no derailleurs to shift it externally, something else has gone wrong. There are a number of reasons that this can happen, such as, the rear wheel has shifted in the dropouts causing incorrect chain tension, the front chainring got bent, or the chain has stretched. While a fixed system is simpler to maintain, when it has problems, those issues usually require the tools and knowledge of a professional.

So How Do I Fix It?
First of all, if you aren't certain what the parts are on your bicycle, check out the Tech Tip Section on Bicycle Anatomy 101. Even if you cannot resolve the problem yourself, you will be able to more effectively communicate what's going on to a bicycle mechanic, which can be very helpful!

Check out the picture below.

(picture of rear derailleur being moved to remove chain tension and put chain on)

If your chain is just sitting there

(picture of chain sitting on bottom bracket but not jammed)

It's helpful if someone holds your bicycle by the handlebar, or you can lean it up against a stable surface. Take the rear derailleur in your left hand and rotate it towards the front of the bicycle. It'll go that way easily (if it doesn't, you may have other problems) and will take the tension off the chain, so at the same time all you have to do is pick it up with your right hand, (yes you will get a little bit of chain lube on your fingers) and rest it on the smallest front chainring. Now if you dropped the chain off the biggest cog, or your front derailleur is positioned in the highest gear, shift it into the lowest gear read on. And, yes, you are breaking the don't-shift-unless-you-are-pedaling rule, but you are allowed to for this particular operation.

What you may find is that it is impossible to put the chain on the smallest chainring because the front derailleur is shifted in the highest gear and/or the chain fell off the largest chainring and is sort of sadly wrapped around the front derailleur.

(see photo of chain dropped off the front)

This is not fatal - just put it back on the biggest chainring.

To make sure that everything is all ready to go, look and make sure the front derailleur and rear derailleur are all properly lined up.

(Picture of bike in gear)

Pick up your bike so the rear wheel is off the ground and pedal a couple of strokes. All should stay lined up and the chain should remain in place. If it pops off again, you may have something else going on and you might want to seek assistance at the shop!

But Everything Is All Jammed?!!!
If you look down and see one of three scenarios

(picture of chain jammed between crank and front chainring)

(picture of chain jammed between spoke and largest cog)

(picture of chain jammed between smallest cog and frame)

What you have to do is fish the chain out without damaging anything, which can require taking a wheel off, taking the cassette or freewheel off the rear wheel, or in the worst-case scenario, taking the crank off. We see this happen when someone drops a chain, and then rides off unknowingly, pedaling, and then they jam the chain. If you can get the chain un-jammed without bending it, scratching your bike, or undue frustration, put everything back and then pick up the bike so the rear wheel off the ground and pedal the bike by hand. If everything seems fine, then try riding the bike carefully and shifting the gears. If it happens again, or you couldn't get it un-jammed in the first place, seek assistance from your bicycle shop. Usually, something has gotten bent or is out of adjustment. Continuing to ride your bicycle could cause more serious damage to other parts.

I Saw This Really Cool Move…
"I was riding with a friend and their chain came off the front and they put it back on without getting off the bike!" Even bikes that are correctly adjusted drop chains sometimes. Poor shifting technique, taking a large drop when mountain biking, chain got knocked off in transport - having the chain come off is not all that unusual on a derailleur bicycle, because as you saw from the pictures above, the rear derailleur is flexible in order to maintain correct chain tension in any gear. If the chain isn't jammed and you've dropped it off the front, usually on the inside, off the small chainring (this is a much harder move to do when dropped off the big chainring!) gently pedaling and easily shifting the front derailleur shifting towards a higher gear, will often put the chain right back where it belongs. Do not do this while putting a great deal of pressure on the pedals because you may just jam it up when it wasn't stuck before. Also, don't do this move in a high speed or heavy traffic situation. Chances are, you will be looking down between your knees at your front derailleur and not what might be in front of you!

If you need more help, please come by Bicycle South. Sometimes a visual example and explanation is more effective. Then, when you have a problem, or a friend has a problem, you'll be prepared!