Slow leak on front cruiser tire I ride my cruiser to the supermarket and back, using either a trailer or a basket over the front wheel for carrying groceries. The bike has developed a persistent slow leak on the front wheel, and I've replaced the tube without it helping. I can't see anything puncturing the tire, and the spokes aren't poking through the rim tape that I can see. 

These are 26" wheels with low pressure (around 40 - 50 psi). What else can I look for that might be causing this?
Mark your tire where the tube's valve stem is located, remove the tube, inflate it and put it in a bucket of water.  Look for bubbles. This is where your leak is. Now inspect the tire and rim at the correlating point for something that may be causing the leak.

Good Luck.