i have plans to do several Time Trial Races This Year. I have a TT bike and was averaging a pace of about 21.5 mph (I’m 62). In hopes of increasing my speed, I bought a Zipp R9 rear disc wheel. I’ve gone on 3 rides and am actually slower 20.5 mph (about my average on my road bike). Does this make any sense? In reading about the wheel, zipp says, regardless of how slow or fast you are, there should be improvement. Ive been riding a TT bike for the last 3 years (about a third of my training). Also riding a road bike. Do i just need to be patient about getting use to it? Any advice would be appreciated. Thanks, Rick