The guy in back gets aproximently 80% gain. Thus pace lines. When the lead needs to recoop. He drops back to the rear of the line and the next rider takes the lead. The over all speed increases greatly. But the pack has to remain tight. Only inches from tire to tire. Not crossing wheels. Also you will se the lines go at an angle left or right from the lead. This is to break cross wind. But I must stress pace lines and drafting are very dangerious. You can not break. You must maintain pace. You must constantly watch the tire infront of you. You can not be distracted period. Otherwise you and everyone behind you is going to the hospital. Being a big guy I have riders try to draft me a lot. I dont like it, if the dont ask. It pisses me off. As it does a lot of riders. I will break thier draft and sprint. I have joined pace lines. But only with riders that know what there doing. Its just too dangerious otherwise.