Front forks feel harsh over bumps

Every small bump is felt sharply through the handlebar, as if the forks do not move enough. Possible causes: front tyre pressure too high, forks binding because they are twisted in the clamps or a tube is bent, too much oil or oil that is too thick, dirty or dry seals and bushes, or the fork is actually bottoming on a bigger bump (which feels like a hard knock).

Is it safe to ride?

Ride with care. A fork that binds can lose grip over bumps in corners.

Quick checks first

• Check front tyre pressure (K-Light 125: 190 ± 10 kPa cold).
• Hold the front brake and push the bars down: smooth, or does it stick?
• Was the fork serviced recently? Too much oil or the wrong grade is a common cause.
• Was the bike dropped recently?
• Thicker oil makes the fork action stiffer. Check that the oil grade and level match the manual.

Diagnose it step by step

1Is the front tyre pressure too high?

• Yes: set it with Check tyre pressure.
• No: go to step 2.

2When you push the forks down with the brake on, do they stick, then jump?

• Yes: they are binding. Go to Front forks feel sticky or stiff.
• No: go to step 3.

3Is the harshness a hard knock on bigger bumps only?

• Yes: the fork is bottoming. Go to Front forks bottom out.
• No: go to step 4.

4Were the forks recently serviced or the oil changed?

• Yes: too much oil, or oil thicker than specified, makes the fork harsh. Ask the workshop to check the amount and grade against the manual (K-Light 125: 285 ± 2 ml per leg, 46#). See Replace fork oil and seals.
• No: go to step 5.

5Are the dust seals dry and dirty, or the tubes rusty?

• Yes: clean the tubes and seals with Clean fork seals. Rusty tubes need a workshop.
• No: go to step 6.

6Does the bike sit high at the front, with very little sag?

• Check with Measure suspension sag. Very little sag with a normal rider can mean wrong springs or spacers were fitted. Workshop.

Causes, most likely first

Reference values (K-Light 125)