2003 Honda Civic Virbation from front end

After putting my aftermarket alloy summer wheels on my Civic after the winter (my winter tires on on the stock steel rims) I noticed minor vibration or rumbling from the front end when I am disengaging the clutch from first, second, and sometimes third gear. The rumble is worse when the car is warmed up, and especially bad when going uphill. It feels like the car is just jolting until the clutch is totally disengaged. The rumbling starts when the clutch is 3/4 disengaged until it is completely disengaged and accelerating. No vibrations when downshifting, through 4th or 5th gear, or any other operation. It feels like the car just isn't "gripping" through the shift. What could be wrong with it? The vibration is freaking me out. I recently had the fuel pump replaced and had an oil change.