No, it's not a Zen meditiation question, it's an attempt to get the right kind of answer to a longstanding question of mine. I've asked this question before, but I don't think it's ever been phrased properly to get a satisfactory answer. Basically, I want to know how silent a modern road bike's drivetrain is supposed to be, and how to know if mine is normal.
When I pedal, I can hear a "whirr" or "buzz" coming from the derailleur pulleys. It's constant, and corresponds to the chain rollers coming in contact with the pulleys. I know the sound comes from the pulleys because the sound can be eliminated by hanging the chain over just a chainring and cog in the same line, bypassing the derailleur.
It's not so loud that I hear it over wind noise, but riding next to a wall makes it noticeable. Putting the bike on the repair stand and pedaling forward allows you to hear it easily. Here's what it's NOT:
- The chain's not dirty, and it's not dry. I keep my drivetrain meticulously clean, and well-lubed.
- The noise is independent of what lube I use. I usually use a light-weight, drier lube, like Prolink or MaxChain. But even soaking it in Tri-Flow as an experiment didn't quiet it any).
- The buzz is also independent of rear gear selection. But the whole drivetrain seems to "purr" just a little more in the big chainring.
- This is not the chain rubbing on the next cog over, as some have suggested. I know that sound from adjusting derailleurs, and that's definitely a harsher, more grating "clicking."
- Nothing else is touching anything it's not supposed to. The guide pulley isn't rubbing the cassette, the chain isn't rubbing either derailleur cage, or anything else like that.
Here are the vitals:
Shimano HG53 chain
SRAM PG950 cassette
Shimano 105 rear derailleur, long cage version
1200 miles on bike, noise hasn't changed since mile 1.
The shameful part is that I just don't know what a quality drivetrain is supposed to sound like. I've only ever had department store junk before, so I don't have any other bikes to compare it to. How stealthy should I be?
If this is what a chain is supposed to sound like, then fine, I'll move on to more important things. And I fully expect that this might be the case. But if it's a symptom of something out of adjustment or whatnot, I'd like to know.