Originally Posted by sch

Previous posters have indicated no problems with such a change. Minor quibbles about cage width and such seem to make little practical difference to those with mid level bikes. You will gain very little out of the change, however as 10 spd offers not much more than panache or bling to the bike. Granted 9spd is so '00, it also is half the price of 10spd equipment on the retail level and is not arguably higher quality, better shifting, significantly lower in weight etc. All that aside it should be a straight forward changeover, bolt on so to speak to swap 10 for 9 spd. There is essentially no difference between 105 and Ultegra front der. 10spd gives you another single step over 9spd for those who can tell the difference in the 17-24mph range. Shimano makes a brazeon to clampon adapter.