The grip on the right shifter on my Fusion has gone gooey on me It's coming off on my gloves and fingers and making a mess everywhere. Is there a known fix for this? The bike is only 4 years old, how long are these things supposed to last? This is the shifter that gets used dozens of times a ride, unlike the one that mostly just goes along for the ride and seldom gets used. that one is still in great shape.