I am chubby and want to lose weight i have a excersise bike i want to know if it Will make me lose weight if i do it for 1hour daily or is the workout just for my legs
Yes, an exercise bike is one of the best exercises for weight loss. If you do it for a long time like you mentioned, you won't gain much muscle but you will burn a lot of fat.
I haven't been overweight, but I have used an exercise bike to trim up, and I still ride it about 3 times per week.
For weight loss, an exercise bike is superior to running because if you are overweight, jogging will probably do long term damage to your knees where biking is quite gentle.
If you burn off more calories than you consume that day then yes you will lose weight and workout your legs. But if you eat a lot of food and then don't burn off as much as you consumed on the bike, then you won't lose weight.