Bicycle Mechanics - What is a perfect drivetrain supposed to sound like? (multispeed)

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.

The perfect sound on a bike is wind wizzin' in the ears and the tires 'icing' on the blacktop with a very faint 'trickle' of the rear cluster as you are coasting down a freshly paved downhill by the light of a full moon.

SHWEEEEEEET :p

What's the rear hub?

go test a "brand new" bike at an LBS. Most will let you do this for free, with little or no hassle. Just act interested and ignorant. If it make a similar (or different) sound, come back and ask them "is it supposed to sound like that? or is it out of adjustment? Generally though new bikes on the floor are gonna be near perfect because A) they are trying to sell them and B) they are brand new and the cables (adjustment) hasn't gotten messed up yet.

That said...here is what my bike sounds like, and I think the drive chain is in pretty good shape (crankset, chain and rear caset all have less than 1,000 miles on them but the derailer has far more...may replace the derailer cogs soon) My bike makes a little bit of noise when I pedal, kind of like a wirring, but can only sometimes be heard, the wind in my ears often drowns it out. going down hill (coasting) you can hear the freehub ticking, I think this is normal too. All in all not silent, but very pleasent.

What's the rear hub?

Ahh...good call. These are the Xero XSR-4 wheels that came with my Giant OCR 2. The hubs are Shimano-compatible, Xero-branded.

The hub is actually super quiet. I almost can't hear anything when I walk the bike through the garage, and coasting on my bike is virtually silent. Even at high speed coasting, when the freehub is a little more noticeable, I can detect less noise coasting than pedaling. The chain noise I describe in my post above is definitely more discernable than my relatively quiet freehub.

So I don't think the hub is the culprit, since the noise I'm intersted in about only occurs when there's chain tension that causes the hub to lock up.

And as for testing a new bike, the thought had ocurred to me. It's easy enough to compare even without riding them, just spinning the cranks ought to give me enough feedback. Maybe I'll head to the LBS and kick a few tires just for fun.

Since you are not moving ahead anyway, why don't you take off the pulleys, look at them, clean them and lube them. I have had success significantly quieting the drivetrain by lubing the pulleys. Otherwise, could the cage be bent? I assume that the tension is properly adjusted making the cage aligned with the cogs.

I'm going to be contrary here and propose the drivetrain as you describe it sounds healthy.

A bike chain is dozens of little metal cylinders (the link barrels) hitting metal surfaces (the gears) continuously. If the sound is strongest from the derailer pulleys, it's because there are three gears close together and three tight bends in the chain path. Single speed bikes are quieter than derailleur bikes, but they're not perfectly quiet either.

I second the suggestion of borrowing a bike shop bike to find out what it sounds like, or just spin the pedal on your bike in front of a mechanic and ask him if it sounds OK. Personally, I suspect that if you have to ride close to a sound reflector (building, car) or bring the drivetrain to your ear to hear the noise, it's not making enough noise to indicate a problem yet.

Chuck it up in the workstand, pedal it, and push on the bottom of the cage in different directions. Maybe there's too much chain tension? Maybe the cage pivot is bent? If you push gently down/forward on the bottom of the cage while pedalling, you will lower the chain tension.

You're positive the chainpath through the der. is ok? It's not rolling over the aluminum guides, right?

If you have the chain off the der, do the pullies make the noise when you spin them or roll them by hand?

If all this is in order, you might not actually have a problem. I'm amazed at how noisy my geared road bike is compared to my single speed MTB drivetrain. Sooooo much inefficiency in there :-/

-Mike

Go to your LBS when they are not too busy and ask them to put a well adjusted high-end bike on a workstand. Trun the crank and shift through the gears. This should give you a real good indication of what a drivetrain should sound like from up close.

You could try a set of Dura Ace pulleys for a quieter drive train, or if you want the silence and the low resistance go with the FSA 153 ceramic cartridge pulleys. If you were going to go with the latter I would only put them in a Record or a Dura Ace derailleur. The long cage is also noisier because of the distance between the guide pulley and the tension pulley. If it was me I would just put a new Dura Ace RD-7700 w/ 13-tooth pulleys on there and see how you like that. You should be able to get that for about 85 bucks and it will work with a 9 sp triple up to 12-26 I think.

I'm going to be contrary here and propose the drivetrain as you describe it sounds healthy.....

My interpretation of your onomatopoeic words (I have no idea what the plural of onomatopoeia is:D) might be a bit off, but I think that it sounds healthy too.

As suggested, you can always test the sound of your bike against a similarly equipped new bike.

Yeah, I actually suspect it's normal. My real problem, I guess, is that I have no good baseline to compare. That means that a visit to the shop to check out a decent sample of bikes will be worth my while.

But in the end, the fact that several people here have described a certain amount of pulley/cassette noise as normal is reassuring.

Well a 'certain' amount of, I'll use your term, pulley/cassette noise Is normal. The problem with that statement is that, a certain amount, is not a quantitative statement.

Every bike is going to be a little different even with the same components because the whole of the bike becomes the sounding board for the noise generated by the drive train.

In my experience monocoup frames are the loudest, Ty and Alum frame bikes are next then steel and composite tube bikes are the quietest as a generalization.

Poorly designed drive trains and lower end components are usually louder, and that is a function of higher resistance or stated another way a greater percentage of energy loss or lower efficiency.

I have found that lube does make some difference in that a waxed chain seems to run quieter than a lubed chain.

I get the same noise with an HG-53 chain and a 105 goupo it also seems to be louder on the large chainring. It doesn't sound like a noise that indicates anything wrong but my bike only has about 100 miles on it and I don't remember it making the noise in the beginning which leads me to believe something is out of adjustment.

I get the same noise with an HG-53 chain and a 105 goupo it also seems to be louder on the large chainring. It doesn't sound like a noise that indicates anything wrong but my bike only has about 100 miles on it and I don't remember it making the noise in the beginning which leads me to believe something is out of adjustment.

This thread is 1+ years old.

Some of us are even older. :(

I get the same noise with an HG-53 chain and a 105 goupo it also seems to be louder on the large chainring.

Just say group. No one will make fun of you for not being OCP.

mine sounds like one hand clapping, in a forest, when no one is there to hear it.


btw, that is very very quiet.

Sounds like nothing. Just put a new chain on and riding right next to a wall (so the sound reflects off of it) and I can't hear the drivetrain. The old, worn chain was audible.

I get the same noise with an HG-53 chain and a 105 goupo ...


Just say group. No one will make fun of you for not being OCP.


i'm not so sure, it says "goupo". maybe it should be "goup" ?

:)

Get in the middle of a peleton for the first time and tell me how quiet drivetrains are. :D