There are many mechanical problems that can occur when riding a bicycle.

Whether you attribute it to the "quirks of the individual bike" or "lack of maintenance" is up to each person, but isn't the desire for a comfortable ride a common feeling?

Here, we will focus on chains and explain what causes problems and how to adjust them for a comfortable ride.

Front chain comes off while riding

When a chain comes off, it often happens with the front gear.

The difficulty of fixing it is relatively easy; it's a breakdown that anyone can fix if they don't mind getting their hands dirty.

It's important to be careful not to push down on the pedals impulsively when the chain comes off while riding, as this can cause the chain to break.

Strangely enough, after experiencing the chain coming off a few times, you learn to stop pedaling the moment it happens.

Is this also a sign of growth?

When the chain comes off the front gear, it usually comes off to the smaller side of the gear.

Without panicking, switch the front derailleur to the inner side (smaller side).

The display will show "1" or "L".

There are two ways to put the chain back on the gear: by hooking it from the top and rotating the pedal, or by hooking it from the bottom and rotating the pedal.

When it works, both methods work, but with the top method, the chain can sometimes come off at a certain point when you rotate the pedal.

At this point, no matter how many times you try, it keeps coming off in the same way, making you feel like you can't fix the chain yourself.

In such cases, hook the chain from the bottom, letting it crawl onto the gear, and slowly rotate the pedal backward (in the direction that pulls the chain up).

Rear chain comes off while riding

It's also quite common for the rear chain to come off while riding.

If the chain comes off while pedaling, it will fall to the smaller diameter side and can get jammed between the sprocket and the frame.

When this happens, it's hard to get it off by hand, which can be alarming.

It would be cool to fix it calmly and smartly, so let's try to deal with it without panicking.

For road bikes, try removing the rear wheel to loosen the chain.

In other cases, it might be difficult to easily remove the rear wheel, so try rotating the tire backward as much as possible, then slightly forward, then backward with a little momentum, and repeat this process until the jammed chain suddenly comes off with a clunk.

If it still won't come off, prepare a tool like a wrench and remove the rear wheel to loosen the chain.

Conversely, if the chain comes off to the larger gear diameter side, it can hit the spokes, potentially breaking them.

Some bicycles have a transparent disc-shaped part (spoke protector).

This is not just for decoration, so take good care of it.

If the chain comes off the rear gear, it's relatively easy to fix.

You should find a small single gear called a pulley underneath the sprocket.

If you push the arm for this pulley (pulley cage) forward, the chain will loosen.

Using this, with the pulley cage pushed forward, engage the chain with the gear.

(Ideally, with the gear indicated by the derailleur)

Once the chain is correctly engaged, slowly return the pulley cage and check that the chain tension is correctly applied.

Then, slowly turn the pedal to confirm that the chain rotates correctly.

At this time, if the gear indicated by the derailleur and the actual gear are different, the chain will shift, so be careful not to turn the pedal too fast, as the chain may come off again.

When the chain frequently comes off

If your chain frequently comes off, the chain tension might not be correct.

For gears, there are combinations that can and cannot be used for the front and rear.

You cannot use the smallest front gear with the largest rear gear, and conversely, you cannot use the largest front gear with the smallest rear gear.

These are the furthest relationships, placing the chain in the position where it is most twisted.

The pulley controls tension with a spring, so the chain tension itself is always good, but the chain is weak to lateral movement.

If you try to force a gear change, the chain can come off.

By understanding that "some combinations cannot be used" and getting used to it, you won't put unnecessary strain on the chain, and you can prevent the chain from coming off.

If the chain often comes off when you're shifting gears, the derailleur's stroke might be off, which I'll explain in more detail another time.

Summary

There are different ways to fix a chain depending on where it comes off.

You'll become an expert after fixing it a few times, so if you practice intentionally taking it off when you have time, you'll be able to fix it smoothly when the need arises.

Related article recommendation: How to deal with a bicycle chain coming off during shifting