This video will show you how to adjust a threaded headset, which was found on most road and mountain bikes in the 90s.
How to Adjust a Threaded Headset
If the front of your bike feels clunky or the bike just gets hard to steer, the most likely culprit is the headset. Most of the time it just needs a simple adjustment and you’ll be riding again.
Below are instructions for adjusting a threaded headset. This type of headset is usually found on older road and mountain bikes, along with some current bikes that are going for “retro” style. (It is called the “threaded” headset because there are threads on the fork’s steerer tube where the headset threads on.)
Step 1: Check the current adjustment.
Let’s start by checking to see if the headset is currently too loose or too tight. First, straddle the bike’s top tube, pull in the front brake, and rock back and forth. If the headset is too loose, you will feel it knocking back and forth.
Now to see if the headset is too tight… Straddle the bike’s top tube and lift the front wheel off the ground (hold the top tube, not the handlebar.) Then use one hand to slowly rotate the handlebars left to right. If they are hard to move or if you hear a grinding noise, the headset is too tight.
Step 2: Loosen the locknut.
Start by loosening the locknut, which is the uppermost part of the headset with wrench flats. (Turn it counterclockwise to loosen.) This usually requires a special headset wrench, such as a 32 or 36mm size.
Step 3a: If the headset is tight…
Turn the adjustable cup (right below the locknut) counterclockwise to loosen it. Start with a 1/8 to 1/4 turn, which is usually enough to loosen things up.
Step 3b: If the headset is loose…
Turn the adjustable cup (right below the locknut) clockwise to tighten it. Start with a 1/8 to 1/4 turn, which is usually enough to tighten it. An easy way to get this right is to tighten it until you feel the cup hit the bearings, then loosen it 1/8 to 1/4 turn.
Step 4: Retighten the locknut.
Now that the headset is adjusted, retighten the locknut to lock in the adjustment. (Be sure the stem and front wheel are still lined up, though!)
Step 5: Check the adjustment.
Repeat Step 1 to see if the headset now turns smoothly without knocking or binding. The key is to keep the headset just tight enough so that there is no play back and forth.
Step 6: Readjust.
Repeat Steps 2-5 if the headset still seems tight or loose. It’s not uncommon to readjust 2-3 times to be sure you got the perfect adjustment!
But if the headset seems right, go ride!