Advertise on Bikeforums.net



User Tag List

Results 1 to 12 of 12
  1. #1
    Junior Member
    Join Date
    Jun 2007
    Location
    Tampa Bay
    My Bikes
    Orbea Onix
    Posts
    21
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Derailler flange hitting chain. Which screw to adjust?

    Question #1: Hopefully, I have the terminology right. But the links to the photos (http://mytruealterego.blogspot.com/2...-problems.html) will explain in pictures. The first photo shows the part that I am talking about (circled in red). When I am on the smallest chainring and the smallest rear cog (as shown in the second picture) the little flange is touching the top of the chain. I was wondering if anyone knew what to adjust. I just changed the rear cassette (only).

    Question #2: While testing the derailleur on the stand after changing the cassette, I was turning the crank with my hands and noticed that when I am on the largest chainring and smallest rear cog, I feel a little bit of roughness (like bearing grinding or something like that). It goes away once the chain is moved away. Any idea what this is about?

  2. #2
    Senior Member 04jtb's Avatar
    Join Date
    Mar 2007
    Location
    West Dorset, UK
    My Bikes
    1983 Dawes Galaxy, 2006 Raleigh Airlite, 1982 Sun Solo (fixed)
    Posts
    908
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by apodysophilic View Post
    Question #1: Hopefully, I have the terminology right. But the links to the photos (http://mytruealterego.blogspot.com/2...-problems.html) will explain in pictures. The first photo shows the part that I am talking about (circled in red). When I am on the smallest chainring and the smallest rear cog (as shown in the second picture) the little flange is touching the top of the chain. I was wondering if anyone knew what to adjust. I just changed the rear cassette (only).
    You shouldn't be using those gears anyway, but if you changed the Cassette, and not the chain, it will get destroyed pretty quickly by a worn chain.

    some links to help you:

    http://sheldonbrown.com/derailer-adjustment.html#chain
    http://sheldonbrown.com/chains.html
    Quote Originally Posted by cc700 View Post
    i jam my thumbs up and back into the tubes. this way i can point my fingers straight out in front to split the wind and attain an even more aero profile, and the usual fixed gear - zen - connectedness feeling through the drivetrain is multiplied ten fold because my thumbs become one with the tubing.
    A group for all Dawes Galaxy owners to give and recieve information about them
    http://flickr.com/groups/dawes_galaxy/

  3. #3
    Senior Member bikeman715's Avatar
    Join Date
    Mar 2008
    Location
    Salinas , Ca.
    My Bikes
    Bike Nashbar AL-1 ,Raligh M50 , Schwinn Traveler , and others
    Posts
    2,078
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    you chain is to long and need to be shorten. to do so you need to break the chain ,remove a link or two so it doesn't hit the cage guide . i take it your new cassette have small gears ?

  4. #4
    Senior Member bikeman715's Avatar
    Join Date
    Mar 2008
    Location
    Salinas , Ca.
    My Bikes
    Bike Nashbar AL-1 ,Raligh M50 , Schwinn Traveler , and others
    Posts
    2,078
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    for you 2nd question check your dérailleur adjustment , the high gear need to be adjusted in or out ?

  5. #5
    Junior Member
    Join Date
    Jun 2007
    Location
    Tampa Bay
    My Bikes
    Orbea Onix
    Posts
    21
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    04jtb: I am confused by your response. Why should I not use those gears e.g. on a decline? I am going to change the chain as well, just waiting for it to get in.

    bikeman715: For Q1, why should the chain length matter now? I only replaced the rear cassette with the same kind...and it wasn't doing this on my old cassette.

  6. #6
    Senior Member
    Join Date
    Feb 2005
    Location
    Oklahoma
    My Bikes
    Trek 5500, Colnago C-50
    Posts
    9,201
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    You should not use the small to small or the big to big combinations (cross-chaining).
    And your chain is too long. There are several methods to check for correct chain length. One check is that when in the small to small combination the rear derailleur should not "bottom out". There should always be some tension on the chain. If you'll do some searching there are several instructions available for sizing the chain. Try http://www.parktool.com and http://www.sheldonbrown.com.

    Al

  7. #7
    Senior Member
    Join Date
    Feb 2005
    Location
    Oklahoma
    My Bikes
    Trek 5500, Colnago C-50
    Posts
    9,201
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Cross chaining causes excess friction in the moving parts due to the chain angle. This makes you work harder and causes excess wear in the drive train over a long period of time.
    What kind of cassette change did you make?

    Al

  8. #8
    Junior Member
    Join Date
    Jun 2007
    Location
    Tampa Bay
    My Bikes
    Orbea Onix
    Posts
    21
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I replaced a Shimano Ultegra 6600 with the same kind because it was worn out. So I guess what's the extent to which you can cross-chain..upto last-but-one OK?

  9. #9
    Senior Member 04jtb's Avatar
    Join Date
    Mar 2007
    Location
    West Dorset, UK
    My Bikes
    1983 Dawes Galaxy, 2006 Raleigh Airlite, 1982 Sun Solo (fixed)
    Posts
    908
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by apodysophilic View Post
    04jtb: I am confused by your response. Why should I not use those gears e.g. on a decline? I am going to change the chain as well, just waiting for it to get in.
    Quote Originally Posted by http://www.sheldonbrown.com/gears.html
    Try to avoid the gears that make the chain cross over at an extreme angle. These "criss-cross" gears are bad for the chain and sprockets. Especially bad is to combine the inside (small) front sprocket with the outside (small) rear sprocket. This noisy, inefficient gear causes the chain to wear out prematurely.
    hope this helps
    Quote Originally Posted by cc700 View Post
    i jam my thumbs up and back into the tubes. this way i can point my fingers straight out in front to split the wind and attain an even more aero profile, and the usual fixed gear - zen - connectedness feeling through the drivetrain is multiplied ten fold because my thumbs become one with the tubing.
    A group for all Dawes Galaxy owners to give and recieve information about them
    http://flickr.com/groups/dawes_galaxy/

  10. #10
    Senior Member
    Join Date
    Feb 2005
    Location
    Oklahoma
    My Bikes
    Trek 5500, Colnago C-50
    Posts
    9,201
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by apodysophilic View Post
    I replaced a Shimano Ultegra 6600 with the same kind because it was worn out. So I guess what's the extent to which you can cross-chain..upto last-but-one OK?
    Was the tooth count on the smallest cog the same on both cassettes? I guess you've already answered that.
    Was the chain also replaced? Maybe you've already answered that.
    If the new cassette is exactly the same as the old then there should be no reason for new chain slack.
    Has the chain been measured for elongation (stretch)?
    A new chain will measure exactly 12 inches over a 24 pin interval. By the time that interval reaches 12 1/16th inches it should be replaced. But from the posted photo it appears that you have more slack than could be accounted for with normal stretch. If the chain now measures OK then it seems you may need to remove one link (that's a full inch). Or at least enough so that the derailleur is putting the chain in tension.
    Edit: Just noticed that you plan to replace the chain.

    Al

  11. #11
    Junior Member
    Join Date
    Jun 2007
    Location
    Tampa Bay
    My Bikes
    Orbea Onix
    Posts
    21
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I just checked and I realized that the cassette I ordered is 12-27 instead of 12-25. So the answer is that the number of teeth on the smallest cog is the same on both cassettes.

    The chain is worn but not so much that it should cause this issue. Sheldonbrown.com says that chains last for few thousand miles and mine must be a thousand at the most.

  12. #12
    Senior Member SweetLou's Avatar
    Join Date
    Jul 2007
    Posts
    2,114
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by apodysophilic View Post
    I replaced a Shimano Ultegra 6600 with the same kind because it was worn out. So I guess what's the extent to which you can cross-chain..upto last-but-one OK?
    There really isn't a correct answer to this. Everyone will say never go big-big or small-small. It has to do with the number of cogs and the length of the chainstays. If you have ever noticed, a chain does not angle to the side very easily. If you have very long chainstays, then the angle of the chain will be less than if you had short chainstays.

    What you want to do is try to have as straight of a chain as possible. If moving from the small chainring to the large and moving to a larger rear cog will give you a better chain line, then you should use that and vice versa. On my 24 speed, I will never go to to the second biggest or second smallest cogs with my smallest and largest chainrings. The middle chainring will never go to the biggest or the smallest cog. Basically, I will only use 6 of the 8 cogs with each chainring.

    Depending on your set up, you most likely have some overlap in gearing. Use Sheldon's (pbuh) Gear Calculator to discover your gear inches. You can print out a small cheat sheet to tape to your stem. Once you know what gear inches, gain ratio, etc. you want, determine which chainring and cog will give you the least angle.

    If you want, you could even black out the combinations that you don't want to use. For example if you have two options that will give you a gear inch of 40.8, black out the one that has the worse chain angle. I haven't done it yet, but I want to set my cheat sheet with blacked out combinations that I never want to use, highlight combinations in orange ok combinations and yellow for best combinations.

Posting Permissions

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