He was 149 against Baldomir. Mosley jumped from 135 to 147 right off the bad, and that's different. I don't think Mosley is naturally much bigger than Mayweather if at all... He just hits harder p4p kinda like Zab Judah who IMO isn't much bigger than PBF naturally. Mosley said his walk around weight was like 155-160 and Mayweather's has been 150-155 so they are very close, and Mosley didn't lose his speed really at Welterweight regardless... Look at his first few fights at welterweight he was almost as quick as he was at lightweight its just he couldn't out power guys like he did at 135 which changes your style. Mayweather has taken his time moving up in weight, and has moved up over a long period of about 5-6 years from super featherweight. Also Mayweather was hitting Baldomir pretty hard the first few rounds... His right hooks that he was countering with were slowing down Baldomir along with the rest of his punches. It wasn't until he hurt his right hand that Baldomir was able to walk in through his punches. I am not saying PBF ever hurt Baldomir or even stunned him, but Baldomir for the first 6 rounds surely was wary of PBF's punching power to the extent that he didn't just walk in on him. THe punches I see Mayweather hit very hard with are his body punches because he is so fast he can put more mustard on those punches than must people who have to watch out for getting countered when going to the body from the outside. Gatti was the other strong guy Mayweather has fought in recent years, and when Mayweather can unload on a guy, and get those hips turning with the punches he hits pretty damn hard. In the week leading up the Gatti fight he went to local gym, and was knocking out light heavyweights with sparring gloves. I didn't say for Mayweather to get up to 160, but 155 is around his natural weight, and alot of you would be surprised him virtually having the same speed as he does now. He still has a few healthy pounds of muscle he can put on without sacrificing speed. The mistake most people make is thinking muscle actually slows you down... it doesn't especially quick twich muscles... it only takes more energy to exert the same movement. Unless you bulk up like body builder you won't slow down. Thats why 100 meter sprinters do weight lifting, and look very muscular. For most boxers it can be a disadvantage because they focus too much on weight lifting and not enough on endurance and punching. Mosley admitted that. Mayweather like Hopkins won't have that problem because he works out so hard. He will never sacrifice endurance for power, and so with a healthy balance he can put on 4-5 pounds healthily on top of the 150 he came in last fight at.