Bicycle Mechanics - Cassette grinding under load.

My bike only has 963 miles on it, and recently the drivetrain has been making a grinding sound in the lower gears of the cassette. It's not coming from the chain rubbing the front derailleur... no cross chaining here. I checked the chain for stretching around 800 miles and it didn't show much wear. All the cables are properly tensioned and I repacked the hubs 2 weeks ago. The grinding is the loudest under torque... like starting from a complete stop or going uphill. Any ideas?

My bike only has 963 miles on it, and recently the drivetrain has been making a grinding sound in the lower gears of the cassette. It's not coming from the chain rubbing the front derailleur... no cross chaining here. I checked the chain for stretching around 800 miles and it didn't show much wear. All the cables are properly tensioned and I repacked the hubs 2 weeks ago. The grinding is the loudest under torque... like starting from a complete stop or going uphill. Any ideas?

Check out what Park's website has to say about adjusting front ders.

Is it more like grinding, or more like a rattle?

Check out what Park's website has to say about adjusting front ders.

It's not the front derailleur.


Is it more like grinding, or more like a rattle?

It's definately a grinding sound.

Look at the rear derailleur. Get close to the jockey pulleys. Check the chainline, is the jockey pulley as well as the cassette cog exactly in the center of the chain? If they are off to one side or the other, they can be grinding on the edge of the next cog.

Also check your derailleur for straight lines. Is it aligned straight up and down?? Could be bent derailleur hanger. Also, check to make sure the derailleur is aligned straight front to back. I had one on a new bike right out of the box slightly skewed and it made all kinds of noise. On my carbon frame, it echoed terribly.

I would really like to know the solution as I have the same problem. It could be a chain lube issue but I'm not sure. I'll stay tuned to see what others think :o...

bump :fred:

can somebody address the original question?

I think croscoe deserves a robust discussion on the causes of grinding in his drivetrain.

What kind/type of Chain lube are you using? How often do you apply it? What kind of conditions are you riding in? (Rain, dusting, road grit, etc..)