Why? That bike is crap and would probably be dangerous on a group ride. Check out the cassette...I can only imagine what the cables are like. To get that bike in proper riding condition you would probably have to invest at least a couple hundred dollars in a new cassette, cables, brakes, tires, grease everything and who knows what else. That's assuming the frame is actually not rusted out or cracked. It's not like the owner has been taking care of it. It's fine for riding to the store maybe, but on a group ride of even a moderate pace I think that bike is an accident waiting to happen. Would you trust it on a bumpy downhill?