I have 8 speed 7400 dura ace sti on my Daccordi. i cant seem to shift into the large chainring (52). when i have the bike on the stand it does it very well from all points. when i take the bike out of my apartment down 2 flights of stairs and on the road NOTHING!!!

i can SOMETIMES shift it into the large chainring when i pedal as soft as possible. But who rides like that?

Oh great C&V what can i do?