Sprocket Does Not Engage

[Hilear]

Brand Brand new to the Forum!

I have a Giant Iguana 640 Bike that has been under the house for a couple of years. Used to ride it quite a bit then life kicked in. Just got re-enthused about riding and decided to break out my bike. I cleaned it up and got the cobwebs off.

I am having a problem and have no idea where to start to diagnose it. Everything looks good but if you pedal, the pedals turn but the the rear sprocket does not engage. I can pedal and pedal but I go nowhere. There is no grinding or unusual sounds.

I would appreciate any advise or guidance as to what could be wrong.

[Joe_W]

Sounds like the freewheeling mechanism is broke / gummed up / rusted. If it is a freewheel, remove that and get a new one (also get a new chain). If you have a freehub and it's Shimano then you might be able to replace the freehub body. Otherwise you have to try your luck with flushing it out (unless it can be disassembled and reassembled, most cannot...)
Also replace the brake pads (at least!) and also cables & housing plus maybe the rusty chain and freewheel / cassette. I guess about... 50$ in parts? (assuming it is a freewheel and you do not have to replace the rear wheel). Also disassemble, clean, grease the head set and wheel bearings (using boat trailer grease, which is water and salt resistant + cheap).

[1FJEF]

The rear gear cluster, which in your case should be a freewheel, not the more modern freehub/cassette has a "ratcheting" system in it. He's right. It and the chain are so rusted I would replace them. Under $30 if you have a friend with a freewheel tool, you can cut the old chain off (or knocj out a pin) if you don't have access to a chain tool. If you got the right new chain it will have a quick connect.
Local bike shop will propably charge $5 to remove the freewheel if you hand them the wheel. The tool is under $10.