Do i need to adjust number of chain links with diff cassette

jez_clarke
jez_clarke Posts: 239
edited March 2011 in Workshop
yo dudes..

i am moving from 11-23 to 12-27 as have a tough ride with lots of climbs and having only two front rings on my dura-ace 7900 chainset i want the extra cogs...

do you think i need to adjust chain tension? i have a new chain too of course as i don't want to be grinding and slipping..

happy riding
jez
bikes:
Trek 9.8
Specialized Langster
Specialised Tri_Cross Comp
Viner Magnifica
and a unicylcle

Comments

  • jez_clarke
    jez_clarke Posts: 239
    p.s.

    it is a straight 10 speed swap to 10 speed swap dura-ace 7900 cassette...
    just a different size
    bikes:
    Trek 9.8
    Specialized Langster
    Specialised Tri_Cross Comp
    Viner Magnifica
    and a unicylcle
  • 52Teeth
    52Teeth Posts: 67
    You should be fine. I have these combinations on different wheels depending on where I am heading / time of year and swap over without worrying the chain.

    Put the cassette on and shift to the 27 (on the big ring) and see if the derailleur has any play left ie can you left the cage arm towards the chain stay with your hand. If you can than off you go.

    You tend to have more problem dropping to a compact chain set, that usually will require a bit of chain shortening.
  • Twostage
    Twostage Posts: 987
    I went from a 12-25 to an 11-28 and then changed the front from 39/50 to 30/42/52 without doing anything to the chain.
    I can really only use the biggest three gears on the back when I'm in the granny ring at the front but that's all I need anyway.

    I might experiment with taking a couple of links out when I change the chain.
  • ADIHEAD
    ADIHEAD Posts: 575
    Swap the cassette and leave the old chain on just for testing, Shift big to big and look carefully at the rear mech. If it seems to struggle then just add a link when you cut the new chain. I'd be surprised if you didn't need an extra link, depending of course on how tight things were to start with. To be honest, if you're unsure then just add an extra anyway, you won't have any negative side effects with 1 extra link!

    To do the job properly then have a look at this http://www.parktool.com/blog/repair-hel ... gth-sizing
  • satanas
    satanas Posts: 1,303
    It's very unlikely you will need to change anything, however it's worth checking to see that the top jockey pulley doesn't rub against the 27T cog when on the small ring. If it does, tighten the B-tension screw until it doesn't.