Originally Posted by MudPie

For the square taper spindle, yes, the smaller diameter tip is the correct size. You just might need more leverage to pull the crank arm off. Do you have an adjustable wrench that is about as long as the crank arm? Often, the position of the wrench and nearest crank arm helps. For example, I ow the instruction say to screw the fixed part of the puller for the entire depth of the crank arm threads. In the past, I've cheated a bit, and backed the fixed part a quarter turn or so (never more than a full revolution), in order to position the adjustable wrench is an advantageous position. It's often easier to squeeze your hands together, while holding the adjustable wrench and crankarm is a scissor action. Or if you position the adjustable wrench and the crank arm at 90 degrees, that gives you good leverage. Once you break the joint loose, like a 1/4 turn, the arms usually slides right off with little to no force. It's just the initial 1/4 turn that is often very hard.