Subject: Re: Chain line Posted by: lew on September 30, 2006 at 08:53:15: In Reply to: Re: Chain line posted by Al on September 28, 2006 at 06:57:37:

Message: >You are correct ... those riders are hurting their TT efforts by crossing over even that moderate amount ... >While you DO want to set up your chain length to allow for all combinations, that does not mean that all combinations should be used! >ONE idea of chainline on a non-single_speed is ensure that a minimum amount of friction is introduced in as many gears as possible ... when the chain is crossed as you described, the links bind (ever so slightly) AND (more importantly!) the chain scrubs the teeth on the chainring & cogs as it engages & disengages with extreme crossovers which results in unnecessary friction & premature wear. >Instead of the 53t & 21t, they/you want to use your inner ring -- so, instead of the 53/21t, EITHER a 42t & 16t/17t cog OR a 39t & 15t/16t cog ... and, instead of the 53/19, EITHER the 42t & 15t OR 39t & 14t (or, equivalent based on whatever your inner ring is to achieve comparable ratios). thanks for your answer.