The two small screws on a derailleur are for fine-tuning?

• A. Yes, they are for fine-tuning.
• B. False, they are preset by the manufacturer and should not be changed (stop limit screws).
• C. They adjust chain tension.
• D. They adjust the derailleur mounting.

Answer: (B)

The two small screws on the derailleur are the stop limit screws. Their job is to set the end points of the derailleur’s travel, so it can’t move the chain beyond the smallest or largest gear. This prevents the chain from jumping off the cog or rubbing on the frame or spokes. They aren’t used to tune the step-by-step shifting between gears. Fine-tuning alignment and shifting is done by adjusting cable tension (with the barrel adjuster) and ensuring the derailleur lines up correctly with each gear. So this is not about fine-tuning; it’s about limiting the derailleur’s range to keep shifting safe and correct.