he didn't say it will only matter if you have a 600 or a 1000. He said it will matter more on a 1000 then a 600 because it goes a whole 20 mph more by your calculations. They don't change drastically but enough to feel and as everyone has said it is there opinion and I believe Bret that you can feel a difference between 160 then 180. He never said he didnt have the money to pay to fix the bike so that might be why he's riding it and since ur not the one lending him the bike I wouldnt worry about it to much.