This has been happening to me on all bikes and I was wondering if it's normal. It doesn't feel like it should be. When I stand to take off from a light or stop sign it feels like it slips a link, but very rarely does it happen. Maybe a little stone or something. I put the bike on the stand and it goes through all the gears with no problem Then I try it on the road with no problems. I looked for bent teeth and I cant find any. I looked for a kinked link and found none. Doe's anybody else have this happen to them?