Chain too short??

galaxyboy
galaxyboy Posts: 168
edited June 2009 in Workshop
Just got a new chain for my galaxy and the new one is around 4 links shorter than the old, will i be okay using it or do i need more links?

Comments

  • galaxyboy
    galaxyboy Posts: 168
    While I'm asking dumb questions, the jockey wheels on the rear derailer rattle a bit is that normal. :?
  • No the jockey wheels should not rattle. Whilst not the ideal way to test it, if you put the chain in the outter ring at the front and biggest cog at the back, see how strecthed out the rear mech goes, if it looks too stretched then there is probably a problem. If your bike ran ok with the extra 4 links before its probably worth having the same length.
  • galaxyboy
    galaxyboy Posts: 168
    Thanks Cyclenoodle but the chains off at the mo'. While cleaning the cogs i noticed that the top jockey wheel moves side to side quite a bit. Looks like it needs replacing too. Can you replace wheels or would i need a new derailer?
  • alfablue
    alfablue Posts: 8,497
    The top jockey wheel is called the guide pulley, and it is designed to have lateral play to deal with any small errors in indexing which would otherwise cause noisy chain meshing with the sprocket. (The bottom one, the "tension pulley" has no play).

    The method for chain sizing that Shimano recommend is to place the chain through the mech, over the large chain ring and small sprocket, and the two jockey wheels should be in vertical alignment - leaning back at the bottom = chain too long, forward at the bottom = too short.
  • galaxyboy
    galaxyboy Posts: 168
    That sounds better alfablue.

    Tried measuring by your method = chain too short.