First off it doesn't weigh more. If you have a pound of fat or a pound of muscle you still only have a pound It is a density issue, muscle is 7 times more dense then fat. So equal size cubes of muscle and fat would have the muscle weighing 7 times more.
But, here is my rant. People are always saying your weight loss is slowing or stopped because you are gaining mucsle. Unless you are in the gym lifting, most likely lifting would have to be your primary goal and not cycling, you are toning your muscles but not building many new ones.
Here's my logic. Say you weigh 350 and have 40% body fat, that is 210 of lean muscle. At 35% body fat you have about 247 of lean muscle. If you got down to a sleek 12% and didn't lose any body fat you would still weigh 235. Typically, you are going to lose muscle when you lose weight. Exercise helps to reduce the amount muscle lost, but to gain muscle is not easy. Your muscles may respond better to effort but that is through training not added muscle.
As a clyde you have more lean muscle then the skinnys have weight
Is my logic flawed? Done with rant for the day.