1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Acceptable chain deflection?

Discussion in 'Fixed Gear and Single Speed' started by Twenty Inch, 4 Apr 2008.

  1. Twenty Inch

    Twenty Inch New Member

    Location:
    Behind a desk
    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
     
  2. andygates

    andygates New Member

    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.
     
  3. OP
    OP
    Twenty Inch

    Twenty Inch New Member

    Location:
    Behind a desk
    No, I meant vertical deflection.

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

    Ta.
     
  4. OP
    OP
    Twenty Inch

    Twenty Inch New Member

    Location:
    Behind a desk
    Cleaned the drive, tightened it up, feels lovely now. Ta.
     
  5. Crock of Gold

    Crock of Gold Guest

    Location:
    London
    OK. I have a "Please advice and Idiot how to..." type question.

    I have tried researching the answer (to help myself) but need it in a language an idiot-boy like me can understand.

    I have changed my back-wheel on my (new) langster so it is now fixed.

    I pulled the wheel as far back as I could to tauten the chain before tightening the bolts as hard as I could.

    HOWEVER...the top part of the chain dips slightly in the middle (gravity I know). It doesn't look like the sleek, straight chain line that I can see on the photos of th bike.

    How do I know that the tension is ok on the chain and what slackness is acceptable?

    Cheers
     
  6. skwerl

    skwerl New Member

    Location:
    London
    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.
     
  7. skwerl

    skwerl New Member

    Location:
    London
    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
     
  8. rustychisel

    rustychisel Well-Known Member

    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.
     
  9. OP
    OP
    Twenty Inch

    Twenty Inch New Member

    Location:
    Behind a desk
    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.
     
  10. Crock of Gold

    Crock of Gold Guest

    Location:
    London
    Just did that. And it worked a treat. Took less then 5 mins as well.

    cheers.