I have a road bike with a Shimano 105 STI rear shifter in what I've seen called "failure" mode. I can shift into lower gears with no problem, but I cannot shift into a higher gear without holding the brake lever in place as the shifter lever sticks to the brake lever when trying to shift into higher gears.
I've done some google searches and determined that this is a somewhat common problem with Shimano STI shifters. However, the only fix I've read about is to replace the shifters - possibly through a warranty. But, I bought this bike used a few months ago and don't have a clue as to the availablility of the warranty as I don't know the history of when the shifters were placed on the bike.
I've tried to flush the shifter with WD-40 to no avail. Any other ideas?
I've thought about replacing the shifters, but I don't want to drop a lot of $$$ into the bike as I may get a new bike in the next six months or so. I've thought about going a cheaper route and placing bar-end or down-tube shifters on the bike until I replace it with a new bike.
My only concern about buying a used replacement STI shifter on eBay or the like is that a used replacement may be on the verge of having the same problem.
I'm wondering if this problem occurred on only a certain timeframe of manufacture of STI shifters. Maybe this problem has been cured in a newer set of shifters. Anyone know?
The shifters are 9-speed version - I don't have the model number with me here at work.
Thanks in advance,