Normal sound of a transmission
 

Hi all,

I am wondering what is the normal sound of a transmission while pedaling. I mean the should produced by the chain while passing through the sprockets and chainrings. How does it sound?

I ask this because I recently bought a new road bicycle (BTwin Triban 3A, MicroShift FD & RD, KMC Z chain) and, after using it a couple of days (going to work, 10 km), I started to notice a strange sound in the transmission that is unfamiliar to me (I had a very old road bicycle fifteen years ago and it's transmission did not produce such sound). The sound I am talking about is not a rubbing, squeak, or even metallic sound, but a very soft hit sound. It sounds as if the bearings/rollers of the chain are hitting the valleys between teeth of the cogs and derailleur rollers. Sometimes I even hear the same sound in the chainrings, but not always.

As I said above, it is a soft sound but, as I am very fussy, I tried to get rid of it. Firstly I tried to clean the chain and put more lube. Secondly I tried to clean the chain again and put less lube. In both tests, even though the first two days the sound disappeared, the sound reappeared after the third day (just 30 kms). Finally, I changed the type and brand of lube. Now I'm using Finish Line Dry (Teflon Plus) and it seems to work better. The first two days the sound in question was softer and smoother than before. I was very happy but today, three days after cleaning and lubing, the sound is turning less soft and more audible. Please, let me know whether it is a normal sound or how can I get rid of such sound. Thank you very much.

Regards,
Pedro

My first question is , what did you clean the chain with and are you sure you got it all out of the chain before you lubricated it? A chain should not need cleaning after a couple of days' riding unless you are going through heavy mud the whole way.

I find the sound of a wet chain with viscous goo on it to be very silent and muffled and reassuring until I land with my right leg down in the middle of the lane at red light intersection over the signal sensor and lean the bike slightly to the drive side to increase the profile of metal over the sensor wires. Then looking down, there is a dark round streak on my calf. Oh well. In my younger days, I would clean my chain constantly and lube so the streak was less visibly dark because the oil was so fresh. In my older age, I just track stand or take the crosswalk like a sissy and and don't have the chain ever brush close to my calf. Or I just tolerate the buzz from a dry lube, which still drives me nuts, but my hearing isn't what it used to be, and with a blue tooth device in my left ear, it's less total noise going in.

I took away the chain (it has a magic link) and rinsed it for a few minutes with a specific degreaser for chains (Hydrocarbon-based). Then I rinsed it again and again with water until the water was clear. After that I dried the chain with paper towels and a hair drier. I left it on top of a paper towel for 20 mins and mounted it into the bike. To lube, I placed a drop on each link of the chain, on top of the roller, and waited couple of minutes before changing to all sprockets and chainrings to "spread" the extra lube a bit. Finally, I removed the remaining lube with a rag, left the bicycle alone overnight and used it the next morning (going to work).

I know that the chain should not be cleaned so often but I was trying to get rid of the "soft hit" sound of the chain. Also, I usually clean and lube the chain if it rains a lot while the bike is parked and as it rained I gave it another opportunity, now wit the First Line Dry.

Thanks for your answer.

With this explanation I get the conclusion that there is a buzz sound (the soft hit sound I mention) that is typical when using dry lubes but it isn't there (or it is much softer) when using wet lubes. Am I wrong?

Thanks for your answer.

Pedro, I use wet (petrol) and dry (wax) lubes and the wax is usually louder with a whirring sound.

Brad

This confirms my thoughts: that such sound is normal. Perhaps it is more audible in my transmission than others, and for sure it is more audible with bad lubes than with Finish Line Dry, but I am relieved to know that it is more or less normal and not an isolated case. Thank you for your answer.

By the way, this morning I cleaned the chain a bit with a dry paper towel to remove some grit, dust, and lint. Now the sound seems to be more soft, but I cannot confirm it to 100 % because the trip to work was a bit windy (and the noise of the wind hides the sound in question). I will comment here whether I can confirm the improvement or not.