I'm not sure if this is where I need to post, but figure a mod can move it if needed. I was gifted an Esquire Nexus bicycle recently. Last week, I decided to put new tires on it as the ones on it were dry rotted. After getting the tires on it and the wheels back on, it wouldn't shift. I only have one gear and am not sure which one it is. This bike has a Shiman push button shifter with a lever under it. The hub is an SG-4R31. All I can figure is the lever under the shifter changes the hub gear and the push button shifter changes gears up. So, to upshift, you push the button and the gears get higher, to downshift, you hit the lever. I took the danged push button shifter apart and now I can't get it put back together correctly. Do any of you know of a site where I can find a schematic break down of how that shifter goes back together properly. I THOUGHT I had it right, but I still can't change gears on this bike. It's very nice bike and I love the way it rides, but I can't change gears and am peddling constantly to go anywhere. Please help me if you can. Thanks.