I've had a complete Ultegra group for about 9 months or 2500 miles. Last 600 to 700 miles the rear derailuer has not been shifting correctly up to the larger sprockets. It will shift from the larger sprockets down the cone ok, but not up the cone well all the time. Sometime I will shift & it will not go up, then I shift again & it goes up 2 rings?
My bike shop has adjusted several times with no success. I've have friends having same problem with same product. I've heard Shimano has an issue with these models, any input is appreciated.
I've changed cables, no difference.