What Happens If A Motorcycle Chain Breaks?

People often ask if a chain on a motorcycle can break and if it did, what would happen. Being an avid motorcycle enthusiastist myself and having restored dozens of bikes, I have seen first-hand that it is certainly possible for a motorcycle chain to break

So, what happens if a motorcycle chain breaks? If a motorcycle chain breaks while riding, you will immediately lose the driving force the engine applies to the rear wheel. It is also possible for the chain to wrap around the back wheel or get jammed on the sprockets which would cause your back tire to lock up and skid down the road.

As you can see, this is a less than ideal situation to be in. If you plan on riding a motorcycle, it’s always a good idea to be prepared for certain scenarios such as this one. Keep on reading to learn how you can handle a broken chain while on a ride and what you can do to prevent it from happening in the first place.

What Happens When A Motorcycle Chain Breaks

A broken chain on a motorcycle can be catastrophic, so it’s important you know how to prevent it and know how to handle it if it does happen. Though it’s not common among those who take good care of their motorcycles, it’s still a possibility.

When a motorcycle chain breaks, there are several scenarios that can take place. You will loose power from your back wheel because the chain is no longer delivering the drive the engine is giving.

The engine will still be going, but you will not be able to accelerate. In fact, your motorcycle may start decelerating if you’re not going down a hill at all. You’ll usually hear a loud clanking sound and feel a slight jolt when a chain breaks.

The most likely scenerio that will happen with the chain is that it will shoot straight back behind you. Though this isn’t necessarily dangerous for you, it could be potentially harmful for any drivers behind you because a chain can blow out a car tire or a windshield.

The second possible scenario that could happen (but is less common) is if the chain either wraps around the back wheel or jams itself into the rear sprocket. This is more dangerous than the first scenario because this will cause the back wheel to immediately lock up; this, in turn, will make the back tire skid and cause you to come to a quick stop.

It it is completely possible for the chain to whip up and hit the back of your leg when it breaks. This is why it’s so important to wear long pants while riding; a chain can do some serious damage to the back of your leg meat with no protection. Wearing pants during a chain break that hits your leg will still give you a hefty bruise, but that’s way better that deep cuts. You can see the riding jeans I recommend for all motorcyclists by clicking here that will offer you some good protection.

I’ve had a chain break while riding; it didn’t turn out catastrophic luckily. It simply fell off and I lost power. But being a mechanical engineer, I do know the physics behind a fast rotating chain and the possible outcomes. I think I got pretty lucky.

How To Handle A Broken Chain While On A Ride

How to handle a broken chain while riding a motorcycle depends a lot on how fast you’re going and how your chain reacts to the break. I’ll cover the common scenarios most people would be in during a chain break and how to handle it.

For some, they may not realize their chain has broken until a few hundred yards down the road. They’re left simply wondering why they’re losing power. This is the best situation to be in if your chain is going to break. Any time your motorcycle loses power despite trying to accelerate, you should always pull over and see what’s going on. If you’re curious about other reasons why a motorcycle loses power when accelerating, see my article here.

If the chain whips the back of your leg while riding and injures you, immediately pull over and call for help. You will need to address a wound like that before addressing your motorcycle.

If you’re driving at lower speeds and your chain breaks resulting in a back wheel jam, you’ll immediately know due to a sudden slow down and the back wheel dragging.

If this happens to you, stop the motorcycle as soon as possible by applying both brakes. The motorcycle may wobble so you will need to attempt to keep it straight as possible while aiming for a place to pull over. You can also keep your feet sticking out a little bit to brace yourself in case you lose control of the motorcycle.

If you’re on a busy road with a lot of traffic behind you and no place to pull over, turn on your motorcycle hazards. Direct drivers to go around you. hopefully drivers behind you will be able to tell you’re in distress because your hazards are on and your motorcycle is wobbling a bit.

You can learn more about how to handle a high speed wobble by reading our article “How To Stop A High Speed Wobble On A Motorcycle.”

What Causes A Broken Chain On A Motorcycle?

Some riders don’t realize that maintenance on a motorcycle isn’t just for keeping the motorcycle functioning well. Maintenance also means increased safety for you as the rider.

With that being said, the main reason a chain breaks on a motorcycle is due to lack of maintenance on it. It takes a lot for a chain to break, so if it comes down to that it means someone seriously neglected to take care of it. There are a few exceptions such as cheap and/or poor manufacturing or the mechanic didn’t tension it right. Be sure to always use high quality chains on your bike and go to a reputable mechanic.

With lack of proper chain maintenance, there are several things that can cause it to break in which rust is the most common culprit. Having a little bit of rust on a chain is okay as you can’t always prevent that from happening, but a large amount of rust is a no-go. Large amounts of rust forms because of lack of lubrication. When a link is rusted enough, it becomes weak and can potentially break.

The other big reason a motorcycle chain breaks is because of the wrong tension. If the chain is too loose, it can come out of alignment with the sprockets which will likely cause a jam. If the chain is too tight, this can cause stress on the links and the weakest link will likely break as some point.

As I mentioned earlier in this article, I’ve restored dozens of motorcycles. I’ve bought tons of project bikes and while I was taking some of them out for a spin to test their limits, the chain broke. That was mostly due to rust and me not examining the chains before taking them out. A lot of my projects had been sitting in a field for years.

Proper Chain Maintenance

As I mentioned before, a chain breaking during a ride is usually preventable with a little extra effort in maintaining your chain. Chain maintenance is one thing you should never skip.

After any long ride or during every oil change, you should clean off any dirt or road grime that has built up on the chain. You can do this by wiping it down with a wet towel or using an air compressor to blow it all off.

Every time you clean the chain, make sure to re-lubricate with chain lubricant. Spin the back tire and lube the entire chain to ensure the whole chain is covered.

Inspect the chain for rust and cracks. If you see an uncomfortable amount of rust or any cracks at all, it’s best to simply replace the chain and not take any chances.

Every chain has one link that comes apart; this is needed to put the chain on in the first place. Look at and examine that link and make sure that link is still in tact.

Be sure to also check the tension of your chain regularly, at least once a month. Each motorcycle is different with how their chain tension should be, so be sure to check your owner’s manual on what tension your chain should be at. Usually street bike chains should not be able to move up or down more than a half an inch.

Conclusion

Having a chain break while out on a ride is pretty rare, but it is completely possible. For it to happen, there has to be some pretty serious lack of maintenance on the chain which is why routine maintenance is so important. If a chain breaks, you lose power and possibly lock up the back tire if the chain gets caught. There’s also a possibility of injury to the back of your leg. So (and I can’t emphasize this enough) be sure to performance regular chain maintenanc on your motorcycle!

Have you guys ever had a chain break while out on a motorcycle ride? What happened and how did you handle it?