Our local bike club puts on a summer time trial series every year . Last year they banned all aero equipment, no aero bars ,discs, aero helmets,ect. What great fun to see everyone time trialing on their regualr road bikes. It made for a more even playing field for those who could not afford expensive TT bikes and aero equipment for only a few races a season. I rode my 1987 Bertoni and finished in about the same place I usually do. The fastest riders still won and the times were about 30-40 seconds slower over a 20k distance. Race participation was way up in the lower divisions which was the intended outcome.