Renold - Troubleshooting Guide: Galling

What is Galling?

The term "galling" is often used to describe the sensation of metal grinding on metal. In motorcycles, this can happen when the chain rubs against the housing or sprockets, or when the brakes rub against the rim. It can also occur when two pieces of metal are forced together, such as when a pedal presses against a crank arm. 

Galling can damage both metals and cause them to wear more quickly. 

The biggest culprit is poor lubrication or using the wrong type of lubricant. It can also be caused by dirt and debris getting caught between two moving parts. To avoid galling:

  1. Keep your chain clean and well-lubricated.
  2. Use the proper lubricant for your bike and the conditions you'll be riding in.
  3. If you're not sure, ask a qualified motorbike mechanic.

What Does Galling Look Like?

Galling usually manifests as shiny metal shavings or as tiny metal balls. It can also look like raised metal flakes or ridges and, in extreme cases, can cause pitting on the surface of the metal. Galling is often most visible when two pieces of metal come into contact. 

You might also notice links begin to bind or kink. This effectively tightens the chain and makes it shorter.

Galling can occur even when two pieces of metal are made of the same material, but it is more likely to happen when two different metals are in contact with each other.

Common causes include; 

  • Friction: When two pieces of metal rub against each other
  • Pressure: If two pieces of metal are pressed too tightly together
  • Chemical Reactions: Certain chemicals can cause galling, especially if they are present in small amounts. These include oils, greases, and coolants.

How Can I Prevent Galling from Happening?

You can do a few things to prevent galling in motorbike chains. First, make sure that the chain is properly lubricated. This will help to reduce friction and prevent the build-up of metals. 

Finally, avoid using too much force when adjusting the chain, as excessive force can cause the metal to deform. 

Here is a list of ways to prevent galling;

  • Lubricate the chain regularly to reduce friction.
  • Use softer materials for contact points between the frame and components.
  • Avoid using too much force when riding or making adjustments.
  • Inspect the bike frequently for warning signs.

What Do I Do if I Spot Galling on my Bike Chain?

If your chain begins to gall, you'll want to take preventative steps to ensure it doesn't cause further damage. You can start by cleaning the chain thoroughly with a degreaser. Once the chain is clean, apply a light layer of lubricant to it. You may also consider using a chain wax or lubricant to prevent galling. 

If galling has caused the chain to kink, work the kink free. Next, mark the location of the kink with a marker. Finally, once the bike has been ridden, review the chain again to check if the kink has returned to the same place. If it has, it's likely too much damage has been caused to the chain, and you should consider replacing it.

Failure to do so could result in additional damage to other surrounding components and yourself.

How to Clean and Lubricate My Chain?

  1. Use an aerosol chain cleaner to remove loose debris.
  2. For more stubborn grime, wash the chain in paraffin or a suitable non-flammable or high flash-point solvent, using a soft brush to work any dirt out.
  3. Wipe the cleaner off and allow it to dry
  4. Apply the lubricant to the top of the lower chain run, so the centrifugal force will work the oil into the chain when the bike moves. 
  5. Let it soak in a few minutes before wiping off any excess.

What are the Consequences of Galling?

Galling can cause damage to both surfaces and can lead to increased friction and wear. This can decrease the efficiency of the chain and can eventually cause it to fail. Galling can also cause premature wear on all moving parts of your chain and associated components.