Ultegra rear derailleur problem
I just bought a used Gunnar Crosshair cyclocross bike. It has Dura Ace shifters up front, a Shimano 105 front derailleur and a Ultegra rear derailleur. When I bought the bike I rode it and shifted it and all seemed well. But on my first ride with the bike I noticed that the rear derailleur shifts weird. It does not skip or shift badly, but it takes two clicks of the shifter to change gears. If I am shifting up for example I click one at a time and all is well. But then I change and want to shift down I have to click the shifter twice and then one at a time after. I had a friend look at it and he tried taking slack out of the cable, played with the adjuster screws. My friend had no luck and said there was a problem with the shifters. The chain and rear cassette seem to have alot of wear, that could be a problem. But why would it seem like it a 10 speed. Could there be a 10 speed derailleur on a 9 speed cassette? The shifter are 9 speed shifters so why do they click 10 times? Does anyone have any ideas?