Fixed Chain Buzz

Green Teeth

I've just changed the chain on my Pompino. The Pompino comes with a 3/32nd chainring and a 1/8th cog and chain. I put on a new 3/32nd chain and cog, but it seemed to be making a nasty grinding noise. I therefore changed back to the 1/8th cog and put on a new 1/8th chain which I've lubed with Finish Line Dry.

I am running this fairly tight, because I've unshipped the chain a couple of times with thrilling consequences. There seems however to be quite a bit of 'buzz' coming from the chain. Previously the drive chain was silent (despite the 3/32nd/1/8th combination).

What do you think? Will it bed in? Do I need to change the cog too? Does it sound like the chain is too tight? Does it sound like the chainline is out?

Any thoughts gratefully received...

GT

Unknown

should bed in

my mountain bike sounds like a tank due to the pitch on the tensioner, its quietened down lately tho as the cog has worn to pitch

Canrider

Agreed. I was sweating the chain unshipping on my first fix due to the buzzing. Never came off, soon quieted down.

---

"We will never win until the oil runs out or they invent hover cars - but then they may land on us." -- lardarse rider

Green Teeth

Thanks for the reassurance folks! Certainly, I did 50 miles on it today and it's running absolutely fine. Looking forward to it quietening down though!

GT

Black Keith

don't run it too tight!

you must use a 3/32 chain with any 3/32 rings/cogs.
you can use 1/8 chain with either.

the chain will unship if some parts are worn or there is a bad chainline.

do not run the chain too tight!



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tony_m

As Black Keith says, don't run the chain too tight!

Both my Pomps have 3/32" chainrings paired with 1/8" sprockets and 1/8th chains, lubed with Finish Line Wet. With the tension set to about 1/2" play at the tightest point (one of these days I WILL find a chainring that's not out-of-round...), they're beautifully smooth and stealthy.

ashbyalien

stupid q. but what will happen if the chain IS too tight?

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Black Keith

it'll

a: wear the drivetrain out quickly
b: probably be noisy
c: result in pain/murder/death

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ashbyalien

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Black Keith</i>

it'll

a: wear the drivetrain out quickly
b: probably be noisy
c: result in pain/murder/death

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<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

i can understand the first two, but, is having the chain tension too tight likely to throw the chain off or something?


[?]

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broachboy

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Green Teeth</i>

Looking forward to it quietening down though!

GT
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

I run all 3/32 components on my commute fix, the only time I get buzz is when the lube is starting to/or has dried out [?] and then it's only minimal? I can safely say the chain(dura-ace) isn't too tight and was replaced at the same time as the ring(Campag) and sprocket(Miche)....

This buzz,Perhaps its a noise from our leg muscles as they get stronger and enjoy proper cycling [:D][;)]

My Fixie

My Volvo

Timeless

but how do you judge what is "too tight"? obviously you do not want it binding at any point of the rotation, but should it be any slacker than that?

if you rotate the crank so that it is at its tighest, and press the chain down halfway between the chainwheel and the sprocket, how much play would you want to see? half an inch? less?

Black Keith

half an inch minimum

on a fixed you should be able to rock the cranks back and forth and feel a little bit of play in the chain, this is normal.

no play = chain too tight
flapping about in the wind = chain too loose




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nashcom

I found that if the chain is too tight (with the bike in a workstand) if you gently spin the back wheel, it stops pretty quickly. If the chain is set to a correct tension, the wheel rotates much more freely.

As you can probably tell, I'm no mechanic, but I've been doing more work on my bike since I started riding fixed. I've found that you just can't trust some bike 'mechanics' to do things properly. It may take me a bit more time, but at least I know that everything is secured and properly adjusted. I use a bike shop I trust for fiddly work, and when I don't have time, but I nowadays I'm able to double-check the work when I get the bike home. I also now know that the guy who originally assembled my first fixie actually sent me away on a potential death trap!

pistonbrew

too tight usually makes grumbly noises, clicks and pings on the way round. as nashcom says, if the wheel spins freely it's ok - if it stops suddenly, or always stops at the tightest point of the chain, the tension needs backing off.



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"The people of Ulverston are liars, drunkards, whoremongers and thieves and follow filthy pleasures" George Fox, 1652.
FGG#2484 & FGG#4529

pistonbrew

ps - dry lube is no good on a fixed IMO - use summat moist : )

__________
"The people of Ulverston are liars, drunkards, whoremongers and thieves and follow filthy pleasures" George Fox, 1652.
FGG#2484 & FGG#4529

ashbyalien

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by pistonbrew</i>

too tight usually makes grumbly noises, clicks and pings on the way round. as nashcom says, if the wheel spins freely it's ok - if it stops suddenly, or always stops at the tightest point of the chain, the tension needs backing off.



__________
"The people of Ulverston are liars, drunkards, whoremongers and thieves and follow filthy pleasures" George Fox, 1652.
FGG#2484 & FGG#4529
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

now, that i understand. ta.

[:D]

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graham_g

I end up getting the tight spot a little tighter than I should be comfortable with (maybe just 5mm of movement) because I hate how loose it gets at the opposite end of the scale! One thing I really hate is anything more than a barely noticeable movement between forward and backwards movement on the crank - puts me off my already shaky trackstands!