Shimano Revo Shift Gives No Clicks I have a problem with my shifter. My bike is using Shimano Revo Shift(gripshift) RS-35 (see my picture).  The one shifting the front derailer (the left shifter) does not click when I turn it but it can still shift the cable.  How do I repair it?  I don't even know how do open up the shifter in the first place.
From the picture, it looks like you have a friction shifter rather than an indexed shifter. Indexed shifters click, and friction shifters move smoothly. For a rear derailleur, you would almost always want indexed shifting because the cogs are so close together. For a crankset with 3 chainrings, friction shifting can be handy for fine-tuning the position of the front derailleur.