It’s natural to be concerned if you hear funny sounds from your bike. When you notice the rear derailleur hitting spokes, you worry.
You ask yourself, “why is my derailleur hitting my bike spokes?”
Other cyclists have varying answers; thus, you turn to the internet but discover so much information.
Many new cyclists also face the same problem, and like you, they find the information from the internet voluminous and confusing.
Fortunately, you discovered a gold mine in this article.
So kindly read on to get brief and concise information about the noise your derailleur makes.
Possible Reasons for the Derailleur Rubbing Against Your Bike’s Pokes
Bent Derailleur Hangers
You must consider the function of the derailleur hanger because it protects the drivetrain from heavy impact. Thus, you should replace a damaged one immediately.
- Signs Your Bike Has a Bent Derailleur Hanger
- Inconsistent shifting across the cassette
- The derailleur completely shifts the chain if you move to the lowest gear or hardest gear.
- Reasons for Having a Bent Derailleur Hanger
- You recently crashed your bike.
- You accidentally hit the derailleur during transport or while riding.
- Your bike tripped on the drive-side.
If you don’t get a new derailleur after an accident, the bent derailleur will create funny noises as it rubs against the spokes.
On the other hand, for minor damages, you can straighten a bent derailleur. However, for extreme damages, get a new one.
- How to Fix a Bent Derailleur Hanger
- Loosen the mounting bolts to remove the bent derailleur hanger.
- Use a hanger alignment tool or an adjustable spanner to strengthen the bent hanger.
- Put back the straightened derailleur hanger in its original place.
Pluck the spokes one at a time to determine which ones are loose. You’ll know they’re loose if they create a buzzing noise upon plucking.
Use a spoke wrench to adjust the loose spokes.
- How to Fix a Loose Spoke Using a Spoke Wrench
- Secure the wrench to the spoke nipple.
- Tighten the spokes by turning the wrench counterclockwise.
- Turn the spokes clockwise slightly if you overtighten them.
- Use an adjustable wrench or needle-nose pliers as an alternative to a spoke wrench.
Wrong Setting of Limit Screws
Misaligned limit screws can cause the derailleur to hit the spokes. Therefore, check them for adjustment.
The limit screws block the chain from dropping into the dropouts or spokes. Generally, tighten them to restrict chain movement.
On the other hand, if you want the bike chain to move outward, loosen the limit screws.
- How to Adjust the Limit Screws
- L-Screw or Low-Limit Screw
An L-screw bars the derailleur from moving forward to the spokes. You can adjust them by following these steps:
- First, check that the L-screw stays within the spokes.
- Next, shift to the smallest cog or ring, then push the derailleur into the biggest one.
- You’ll notice that the upper pulley aligns with the most extensive ring or cog.
- Tighten the L-screw clockwise if the top derailleur pulley moves to the spokes and goes beyond the enormous circle.
- Shift to the second largest cog to loosen a too-tight L-screw, then push the derailleur into the vast ring.
- The chain should stay as you pedal. If it does, reduce the L-screw until it stops skipping.
- H-screw or High-Limit Screw
Adjust the high-limit screws if you fail to correct the limit screws. They allow the smooth movement of the bike chain into the cassette without dropping and slipping off.
You may adjust the high-limit screws by following these steps:
- First, shift into the cassette’s most petite ring.
- Next, loosen the chain tension if the derailleur doesn’t move.
- Finally, repeat the process until the top pulley is below the most petite ring; turn the h-screw clockwise.
- If you hear the funny noise as you pedal, loosen the High-limit screw slowly until you don’t hear the rubbing noise anymore.
Incorrect Derailleur Cable Tension
The derailleur will rub against the spokes if there’s an issue with the cable tension. Therefore, you should tighten it to ensure smooth shifting.
- How to Adjust the Derailleur Cable Tension
- Use a barrel adjuster to reduce the cable tension by turning it clockwise.
- Turn the barrel adjuster counterclockwise to increase the tension.
Reasons Why Your Bike Spokes Break
Bent or Broken Wheel Rim
You can fix a bent or broken wheel, but remember to do it on a suitable bike stand.
Rust can undermine the spokes and may eventually break them. Therefore, you should replace rusty spokes.
You may eventually get broken spokes if you have non-stainless steel or low-quality spokes because they can’t handle the pressure.
An aggressive rider can break the spokes, especially if the bike isn’t for aggressive cycling.
If you’re heavyweight, you may overload the bike wheel and break the spokes.