Any trick to chain alignment?- Mtbr.com
Results 1 to 14 of 14
  1. #1
    mtbr member
    Reputation: Casual Observer's Avatar
    Join Date
    Jan 2004
    Posts
    9,211

    Any trick to chain alignment?

    Gone maybe 4 months without dropping a chain, and then dropped it three times in 10 miles yesterday. The chain appears to be aligned okay, but I'm basing this purely on visual confirmation. Any other tricks to making sure the chain is aligned?

    If it's not the alignment, how much slack should I have? I'm running an EBB, and I have the chain as tight as possible without taking a link out.
    Nobody gives a s#$t you singlespeed.

  2. #2
    mtbr member
    Reputation: boomn's Avatar
    Join Date
    Jul 2007
    Posts
    10,016
    there are measurement tricks, but imho if it looks straight then it should be good enough, especially considering how frames can flex side-to-side anyways

    Tightness is definitely important. Rule of thumb I heard and follow is that you shouldn't be able to push the middle of the length of chain up or down more than 1/4". Basically, tighter is better as long as it doesn't bind because of irregularities in ring and cog roundness

  3. #3
    Come see me after class
    Reputation:
    Join Date
    Dec 2005
    Posts
    1,431
    some people like to run their chains so slack that you can see the sag in the chain. i like to keep my chain pretty tight. just don't make it so tight that you can't freespin the pedals backwards a few spins by hand.

    the way i check to make sure my chain is not too loose is simple: try to remove the chain by hand without removing or loosening the wheel. if you can get the chain off the chainring or cog, it's too loose (in my opinion).

    if it's too loose, lose a link and dial out your EBB.

  4. #4
    Did I catch a niner+?
    Reputation: Mr Pink57's Avatar
    Join Date
    Jul 2009
    Posts
    2,954
    Take a picture of the front of the bike and shows all the way through the chain line. This can help to see if the chain is off, I am sure they're are measurements but eye balling I think is fine. 5mm either way is acceptable I think. I keep mine at the 1/4" rule anything tighter and it seems to bind.
    Mr. Krabs: Is it true, Squidward? Is it hilarious?

  5. #5
    mtbr member
    Reputation:
    Join Date
    Nov 2004
    Posts
    273
    a long straight edge lay it against the ring and cog to see if its square

  6. #6
    achiever
    Reputation: redwarrior's Avatar
    Join Date
    Apr 2007
    Posts
    927
    Yes, there are definitely tricks to proper chainline measurement. It is entirely possible to do it by sight. I would disagree with Mr Pink57, though. I think 5mm is way off and would cause you trouble. But I could be wrong. As for tension, I can hear when my chain needs tightening, it gets noisier due to the slack, I guess.

    These two links helped me. I've got mine set exactly the same both front and rear and haven't dropped a chain in a few thousand miles. Another tip not mentioned in the link is to use a set of Vernier calipers to make the measurements. I find it a lot easier to get a good read than with a ruler.

    http://www.sheldonbrown.com/chainline.html

    http://www.parktool.com/repair/readhowto.asp?id=110


    Good luck, if you've got any more questions, post 'em up.


    Red

  7. #7
    @adelorenzo
    Reputation: anthony.delorenzo's Avatar
    Join Date
    Aug 2006
    Posts
    1,670
    If it was fine for 4 months, I doubt you suddenly have a chainline issue.

    Replaced the chain yet? It could be worn chain, and/or chainrings and cog. If your front ring is sharp and pointly like shark's teeth, it could be time to replace.

  8. #8
    mtbr member
    Reputation:
    Join Date
    Feb 2007
    Posts
    44
    i used to throw mine a lot, then measured, now not so much. i've been running a kmc kool chain too which helped quite a bit. tightness helped.

  9. #9
    Drinking the Slick_Juice
    Reputation: nuck_chorris's Avatar
    Join Date
    Jun 2008
    Posts
    1,809
    a while back ago some one on the forums suggested that you put the cog on your freehub body with no spacers and install the wheel on the bike and hold the rear brake lightly while you turn the cranks. ive done this and it has worked great, my chain does not slip at all
    "If women don't find handsome , they should at least find you handy."-Red Green

  10. #10
    mtbr member
    Reputation: asphaltdude's Avatar
    Join Date
    Sep 2008
    Posts
    643
    No one mentioned the 67.5 rule yet?
    Ride more!

  11. #11
    achiever
    Reputation: redwarrior's Avatar
    Join Date
    Apr 2007
    Posts
    927
    Quote Originally Posted by asphaltdude
    No one mentioned the 67.5 rule yet?

    Assuming he has a 135mm spaced hub (which is a fairly safe bet, I admit).

    Pretty sure that method is covered in the links I posted above.

  12. #12
    meow
    Reputation: Cato's Avatar
    Join Date
    Feb 2004
    Posts
    588
    Are you running a stainless steel ss specific ring up front? Aluminum wears out fast, can bend, etc.

  13. #13
    mtbr member
    Reputation: boomn's Avatar
    Join Date
    Jul 2007
    Posts
    10,016
    Quote Originally Posted by Cato
    Are you running a stainless steel ss specific ring up front? Aluminum wears out fast, can bend, etc.
    most steel MTB rings are even more likely to bend than similar aluminum rings because they are made from somewhat soft stainless.

  14. #14
    mtbr member
    Reputation: djriddle's Avatar
    Join Date
    Oct 2008
    Posts
    138
    I notice no one said to take it to a shop... I don't know if there are any actual mechanics weighing in on this one but there are specific tools to measure chain allignment. Checking the tightness of the chain is pretty simple and like was already said the 1/4" rule is sound on single speeds. There is also the possiblility that your chain ring, rear cog/freewheel and chain have all worn out from use, but typically such extreme wear takes thousands of miles. If one or two of these parts has been replaced and one or more of the old parts were left then you may have issues with worn edges not fitting with new ones. The easiest way to tell if you gear teeth are worn is to compare them to new ones and there are several good tools available to measure the wear of a chain. The trailing edge of you rear teeth wear, the leading edge of the front teeth wear and the round roller of the chain wears. If you are running a chain narrower than your gear teeth, it will also have a tendency to slip, especially under load. Chain line can be an issue, but if you are using a chain made in the last twenty years you can get away with about a quater inch or so of misallignment. Remember that on multiple speed bikes that chain line can be REALLY bad in certain gear combinations, but since you do not have a derailer you can't get away with 20 or 30mm. If you have a loose BB, chainring bolt, rear hub bearings, cassette lockring or rear hub (QR or bolt on) loose in the dropouts you might dump your chain so check those too. If none of this works take it to your local shop and see if they can't figure it out. A six pack or pizza will get you far with these jokers so remember a little bribe can get you a long way in a good shop. Hope this helps and keep the rubber side down...
    BBI certified, 12+ years as mechanic

Members who have read this thread: 1

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

THE SITE

ABOUT MTBR

VISIT US AT

© Copyright 2019 VerticalScope Inc. All rights reserved.