Acceptable chain deflection?

[Twenty Inch]

Hi there

Are there any guidelines or practise around the right amount of chain deflection for safe cycling? I have about 1/2 inch on my fixie.

Cheers

 

[andygates]

If you mean sideways deflection - deviation from a percet chain line - it'll be noisy and rough WAY before it's unsafe.


Otherwise about 1/2" is about right. Too tight and it binds or gets noisy. Again it's bad before being dangerous: you'll feel a slack "flub" (there's no other way to describe it) as you reverse pressure between driving and braking. Flub is bad. Flub is the sign that it's tightening time.

 

[Twenty Inch]

No, I meant vertical deflection.

There's a slight bit of flub, but not much. Might tighten it up slightly before this evening.

Ta.

 

[Twenty Inch]

Cleaned the drive, tightened it up, feels lovely now. Ta.

 

[skwerl]

if it dips then it's probably too slack. You need to set the wheel offset to the non-drove side then tighten (a bit) the non-drive bolt. Push the rim so that the wheel centres (the key here is to get a little slippage in the non-drive bolt, otherwise the wheel won't stay centred) then tighten the drive side and fully tighten non-drive. that should give you more taughtness in the chain. you can't get enough pull by just yanking the wheel as far back as it'll go. the chain should spring back to position when prodded in the centre of it's longest run.

 

[skwerl]

No, I meant vertical deflection.

There's a slight bit of flub, but not much. Might tighten it up slightly before this evening.

Ta.

you need some flub otherwise the chain will bind. it depends if you're measuring deflection on the tight or slack sections of your chain-ring.

lft the rear and spin the cranks. the wheel should continue to splin for quite a while before slowing gently to a stop. if it decelerates quickly and stops after a few revs then it's binding and too tight

 

[rustychisel]

wot skwerl said. There's a school of thought sez if you have a nice tight topline on the chain then it's too tight. You'll feel it if it starts to bind. Then it'll chew up your wheel bearings.

 

[Twenty Inch]

Yes, there's a definite "too tight" feeling. I reckon I've got it right at the moment, it's lovely and responsive without being flubby or binding.