We are aware of the nuisance that this means as we ourselves as regular cyclists also suffer from it and we try to solve it definitively, but unfortunately this is not always the case as maintaining the bike at 100% is not always possible.
After checking many bikes in our workshop, experience tells us that the main problem comes from the maintenance itself.
Here are some simple steps to improve this problem.
1.- Cleaning and greasing
Have a good cleaning and greasing of the entire drivetrain: cranks, derailleurs, chain, sprockets, wiring. If everything is clean and greased, there will be less chance of the chain coming off and we will not generate other mechanical problems because the gears do not work due to dirt, accumulated mud, or a seized chain due to lack of lubrication.
2.- Transmission management
We should avoid abrupt gear changes, anticipate the terrain and gradient ahead of us and start shifting gears in advance. If we are coming to the end of a descent and we see that there is a hill ahead, we should not wait until the end of the hill to shift up gears or down chainrings, nor should we try to shift to the largest sprocket and the smallest chainring at the same time as soon as the hill starts. If we want to change gears abruptly, there is a good chance that the chain will come off. Obviously we don't always know the terrain and there are times when a mistake is inevitable.
3.- Detection of mechanical faults
Most of the problems derived from the maintenance of the transmission will originate mechanical failures. A worn chain will cause the gears to be sluggish or even come off. Periodically the chain should be measured to check its condition. A worn chain not only causes problems with the gears, it also causes excessive wear on the sprockets and chainrings. Similarly, chainrings or sprockets with worn or broken teeth will also cause the chain to come off.
4.- Adjusting the derailleur gears
Many of the problems with derailleur derailleurs also cause the chain to come off. Faults in the derailleur controls or in the derailleurs themselves must be corrected. Cable controls may sometimes require cleaning and/or greasing, although the problem usually lies in the derailleurs themselves, these must be perfectly adjusted, adjusting them is easy and you can consult our tutorials on Youtube.
Often the rear derailleur derailleur hanger, when exposed to impacts, can get out of adjustment, which will affect the correct functioning of the drivetrain and will also cause the chain to come off.
In addition to these tips, it is also possible that the bicycle may have an assembly error, the most common being:
1.- The chain is not passed on the correct side of the chainrings.
2.- Wrong direction of the chain.
3.- Lack of seals or spacers on the bottom bracket that is off-centre with respect to the sprockets.