I have a 2018 Cervelo P5 and use Enve 7.8 wheels to do some local TTs as well as Oly, HIM, and IM triathlons. I’ve been exploring full disc rear wheels and contacted ENVE, Zipp, and Specialized about their offerings and wanted to get some group wisdom.
Per ENVE, they say riders are better off on their deeper 7.8 wheelset vs. their newly released disc wheel if they cannot sustain 27+mph. I cannot sustain that over the course of a race.
Per Specialized, their new Roval 321 disc is only 4 seconds faster over a 40K TT (across a variety of yaw angles and speeds). I was shocked they claimed only 4 seconds faster.
Per Zipp, they wouldn’t give me a watt or time saving for their Super 9 disc wheel, but sent me a CFD picture showing me the drag coming off a 808 rear wheel vs. Super 9.
My A race next year is Ironman Arizona which is characterized by a 10-12 mile 1-3% grade going out of town, which riders get the benefit of going back into town (I assume 27+ mph possible for this part, depending on wind).
All of the data from the companies is pointing me towards NOT upgrading to a full rear wheel, but I wanted to hear from those of you who may run a full disc. I know the TR crew used the prototype ENVE disc wheels in their time trial effort this summer, but perhaps they can maintain a very high speed. I’ve got no interest in a disc cover given I’ve got some pretty good wheels already in the 7.8s.
Any thoughts and expertise will be appreciated!