Thanks, I did a high res x ray of one when I worked in aerospace and could see the ply angles and the woven and UD plies, also noted some glass tracers that showed up very well. I determined that it was RTM molded in one shot but nice to hear it from the horses mouth 
What did you mean by ‘glass tracers’?
“I worked in aerospace” …
As an internal ME consultant, I usually did product line troubleshooting, failure analysis, and some machine design for all of the DuPont plants, including some in western Europe. Before this wheel project, I first got into composite work for that same division’s industrial/aerospace group, designing “momentum wheel” composite structures for satelites. I recall they had to survive severe ~ ‘white noise’ vibration at rocket lift off, severe temperature variations and avoid natural frequencies including the beneficial gyroscopic stiffeneing effects.
It was the steady loss of that west coast aerospace composite work in the late 80’s that pushed project leader engineers there (Mark Hopkins and Frank Principe) to hustle work from their athletics group and the bicycle wheel.
RTM evolution: When those two marketing guys from DuPont’s relatively new Composits Group, first asked me to do the job, I refused because they were being forced to use a loser “door frame” mfg’g process. Dupont had spent ~5-10+ million $$ on trying to make a new automotive door frame using a twisted composite rope for the main structure, bonded inside an exterior door panel, but never were able to make it work without creating visible flaws in the panel.
They later send out an email invitation to myself & others to a meeting about how to make this crude door-frame method could be used to make light, high performance wheels. They requested that nay-sayers stay home, and I obeyed. Luckily someone suggested the RTM process, and I said I’d help on that basis.
The wheel was advertised as including Dupont’s famous Kevlar fibers, but this was a stiffness driven design, and Carbon fibers were stiffer and my preference. But I was told to include Kevlar, so I added a small amount in a non-critical area. On either side of the spokes near the hub, I specified patches of 60 million psi uni fibers, twice the Modulus of Elasticity of steel. This was to increase the lateral stiffness at the rim.
