chainring help

chatlow
chatlow Posts: 848
edited December 2013 in Workshop
Got a 2010 Giant TCR Advanced 4. It's a 105 setup and is running 39/52 chainrings.
Is it possible to replace the 39 ring with a 34 or do I have to look at replacing other parts?

Thanks

Comments

  • buckles
    buckles Posts: 694
    I think you'd need a compact chainset (110mm BCD)
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  • No you can not get a 34 on a non compact chainset , it is to small for the bolt pattern.
  • diamonddog
    diamonddog Posts: 3,426
    halfround wrote:
    No you can not get a 34 on a non compact chainset , it is to small for the bolt pattern.
    ^^This
  • chatlow
    chatlow Posts: 848
    Noted. Thanks. What about replacing the 36t chainring with a 34t on my carrera virtuosa winter road bike?
  • If it has a 36 on it now its a compact and a 34 will fit. But 36 inner comes with 52 outer and the size difference 52 / 34 is to big. So you would have to replace both rings. Most low end bikes come with 50/34 as 52/36 is called pro compact.
  • chatlow
    chatlow Posts: 848
    Ah nothing is ever simple! So it looks like I need two new 110 34/50 chainrings, a cheap RD that can handle 28t and a chain to go with it all. Prob cost more than the bike itself!!
  • chatlow
    chatlow Posts: 848
    Ooh - it turns out my bike is a freak and is running a 36/50 setup - so will only need the one chainring!
  • Result, just need a 34 then and your set.
  • maddog 2
    maddog 2 Posts: 8,114
    you're
    Facts are meaningless, you can use facts to prove anything that's remotely true! - Homer