A bike chain can skip under load because the chain or cassette is worn, the drivetrain is misadjusted, a link is damaged, the derailleur hanger is bent, or recently replaced parts do not mesh together. Avoid hard pedaling until the cause is found; an unexpected skip can make you lose balance.
Notice the pattern
Does the skip happen in one gear, across many gears, or only after installing a new chain? One sprocket points toward local wear or damage. Broad problems can involve chain wear, adjustment, cable tension, hanger alignment, or compatibility.
Stationary checks
Look for a stiff or damaged link, measure chain wear, inspect the cassette for obvious damage, and confirm the wheel is secure. Shift gently through the gears on a work stand if you can support the bike safely.
Do not reproduce the fault with a high-force road test. Do not adjust limit screws randomly; they control derailleur travel and incorrect settings can send the chain into the wheel or frame.
After installing a new chain
A fresh chain can skip on a cassette that has worn to the old chain’s pitch. The solution may include cassette replacement, but a mechanic should confirm compatibility and condition. Start with chain wear measurement.
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More drivetrain care guides
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Video by Global Mountain Bike Network · Watch on YouTube