TRIONLAISA
All symptoms

Front dives heavily under braking

When your bike shows "Front dives heavily under braking", these are the most likely causes - ranked by relevance: Compression, Air pressure, Sag. LAISA separates setup causes (adjusters, components) from riding technique.

Short answer for this problem

Recommended starting point
Check first: Fork: Compression
Most important change
Smallest documented change: 1 click - clicks out from fully closed
Why
The compression is too soft - add some to control the brake dive.
How to test it
Read the current value off the bike and compare it with the recommended one. Write it down before you change anything.
Source
LAISA diagnosis catalogue, drafted automatically and editorially released Methodology
Last reviewed
No review date documented
Pick your bike to apply the fixes directly

The order comes from the stored strength of the symptom-cause link in the catalogue - per symptom, not across symptoms. These are not probabilities and not measurements.

Suspension

Fork: CompressionCheck first

Why this could fit: The compression is too soft - add some to control the brake dive.

How to check it: Read the current value off the bike and compare it with the recommended one. Write it down before you change anything.

Smallest change: 1 click - clicks out from fully closed

Fork: Air pressureCheck next

Why this could fit: On air forks the air pressure is too low - raise it; on coil forks fit a stiffer spring.

How to check it: Read the current value off the bike and compare it with the recommended one. Write it down before you change anything.

Smallest change: 0.1 bar

Shock: SagCheck next

Why this could fit: Too much sag / a soft setup tips weight forward - reset the sag.

How to check it: Read the current value off the bike and compare it with the recommended one. Write it down before you change anything.

Smallest change: 1 mm - loaded, rider in gear

How to set your sag
Calculate a setup for my bike

Free. Pick bike, track and riding style.

Related symptoms

Arm pump after a few lapsEngine stalls in tight technical sectionsFork harsh on small roots and braking bumpsFront deflects off roots and rocks

A starting point to verify on the bike - not a safety guarantee. Change one thing at a time and check on track.