That's a new one! The only challenges I've had were the rubbing of my bra strap over the pacemaker. I solved that by buying a little triangle of cloth that was very smooth and easily attached to the bra. I don't need it anymore. I finally discovered why I was getting pains in my chest--wearing my purse strap on my left shoulder. I either carry my purse, sling it over my head so that the weight is on my right side. Keep up the biking. I have a mantra. "If you don't move. You don't move." I've just lost my walking companion. A little dog by the name of Miah. My granddaughter is encouraging me to get another. If your pacemaker is moving around, I suggest that you get it checked. The last thing you want to happen is to get those wires loose. Good luck!