I just took my new bike for a test drive. It's been decades since I've ridden a bike...and the first time I've been on one that required shifting, so I'm wondering if what I'm feeling is normal: I'll be feeling resistance in the pedals, but then for a second I'll lose the feeling of resistance and the pedals feel like they're turning freely for a few degrees - as if they're not connected to anything...then all is back to normal. It's not something that happens during shifting, it's while I'm in gear. I bought the bike at Dick's, and I was totally sure they mis-adjusted something, but I took it back in and they checked it out and said everything's fine. Is this the way a normal functioning bike should feel? It seems like it would get annoying pretty fast.