12/25??? 12/23??? 11/30???

[Fozz]

i`m about to upgrade from shimno 2300(8speed) and FSA (tempra) to an almost complete 105 groupset, i sourced all the parts except the STi shifters, so all i`m doing, presumeably, is "dialling out" the 9th cog at the rear.

thats what i hope anyway......

 

[GrasB]

You may not be able to get away with that on a 8spd to 9spd transition, iirc the indexing is slightly tighter on 9spd cassettes.

 

[Dan B]

You may not be able to get away with that on a 8spd to 9spd transition, iirc the indexing is slightly tighter on 9spd cassettes.

A fairly comprehensive guide to sprocket picth and pull ratios: http://www.ctc.org.uk/desktopdefault.aspx?tabid=3946

 

[Fozz]

sorry should have mentioned, i`m keeping the 8 speed cassette to match the sti`s so i`ll just restrict the new 105 derailleur

 

[fungus]

What year is your bike, 2010 were blue/black/white 2011 are black/blue? I've got a Defy4, nice little bike now I've upgraded the wheels & a few bits n bobs. I'll be able to point you in the right direction once I know what you have on it now

 

[fatboysoontobeslim]

its a 2010???