What is Ghost Shifting?
Ghost shifting or phantom shifting, as it is also sometimes referred to, is a spooky way to describe what may look as an equally spooky condition you may experience in your bike. In short, your bike will shift gears without your consent. Strange? Not that much, actually.
You may notice ghost shifting at high speeds, as you feel you need to pedal harder than normal without actually making any changes to your gear. Luckily, there’s no ghost to bust. Moreover, the problem could usually be resolved with a simple solution.
What Causes Ghost Shifting?
When you experience ghost shifting, you should check where the problem is in order to solve it. Many times, cable tension may cause your derailleur to open and, thus, make your chain shift into other gears.
If your bike is brand new, cables tend to become loose within the first rides. It’s completely normal, and one of the main reasons why you should have your new bike checked and adjusted after approximately six months’ use.
Most local bike shops offer a free tune-up within the first year after buying a new bike. If your bike is not brand new, cables may also become stretched with regular use -another good reason for a periodical tune-up.
Ghost shifting may also be caused by a bent derailleur, or derailleur hanger.
These are not as common as a cable stretch for the only reason that, in order to get bent, your bike must have either crashed or dropped, which you would obviously remember. Still, it’s not an option to discard completely when experiencing this problem.
How To Fix Ghost Shifting
If the problem is caused by cable stretching, you need to identify which derailleur is involved.
If it is the rear one, you first need it to be shifted into the smallest chainring and then try to shift up. If it doesn’t, tension is needed. To do so, twist the barrel adjuster opposite from the brake lever. Do it in small turns; half a turn will do. Try shifting again, and repeat the process until it works properly.For the front derailleur, the process is exactly the same, with the only exception that, as it is the other barrel adjuster you need to twist, it screws in the opposite direction.
Check this video on how to add tension to your shift cables (credits to Park Tool):
If this does not solve your ghost shifting problem, or if you find out it is caused by bent derailleurs due to crashes or drops, it is highly recommended to ask your local bike shop. As it may be solved without replacing the gear, it always depends on the damage dealt to it.
Be careful if you try to do it yourself. Remember that inexperience in these cases can result in accidentally damaging your ride more than at the beginning.