Deeper and stiffer.
HED numbers its carbon wheelsets in sequential order, and while the Stinger 7 falls smack between the Stinger 6 and 9, it's not placed there on depth alone. The Stinger 7 FR Carbon Tubular Road Wheelset has been specifically designed to be a step above the Stinger 6, which is a well-rounded race wheel, and its accolades hail from it being a dangerous weapon under a capable sprinter.
Yes, it's true that HED engineers reinforced the sidewalls of the 75mm-deep carbon rims, making them extremely stiff and responsive and an obvious choice for a powerhouse like Cavendish or Greipel. But what sets the Stinger 7 apart from other wheels optimized for those last few blistering seconds of a race, and adds to its versatility, is HED's Stability Control Technology which handles all of the other kilometers leading up to those final 200 meters. SCT specifically addresses the Stinger 7's shape to improve stability in crosswinds, thus countering one of the biggest drawbacks to running deep section wheels.
In addition to Stability Control Technology, HED engineers also incorporated C2 Technology into the Stinger 7. C2 stands for two Cs: lower coefficient of rolling resistance (Crr) and better aerodynamics (Cda). The rims on the Stinger 7 Wheelset are 28mm wide when most rims are around 23mm, and it makes a big difference. A 28mm rim paired with a 23mm tire changes the tire's footprint. It grips better in a straight line, and it grips better in turns because the tire has a straighter sidewall and deforms a bit less at a given pressure. A 23mm tire on a 28mm rim also has lower rolling resistance. HED sent the wheels to Continental Tires for testing. Conti's engineers shrugged their shoulders and figured there was no difference, but they put them in their testing jig and ran the tests anyways. As it turns out, Hed's C2 rim design offers 18% less rolling resistance than typical narrower rims. And because of the smoother transitions from tire tread, to sidewall, to rim, and finally to the trailing edge of the rim, the airflow is less disturbed. The result is a more laminar air flow and a lower aerodynamic drag. And although it initially seemed like an awkward marriage, the industry is following. Yes, it's a good idea to run 23mm or wider tires on any of HED's C2 wheels.
The Stinger 7s come standard with HED's Carbon FR Sonic hubs. The hubs have a carbon fiber center section and use a minimalist shape in order to maximize aerodynamic characteristics. Both the front and rear hubs run ABEC5 bearings on oversize aluminum axles: 12mm in front, 15mm in rear. The oversized axles are stiff, and with less deflection the bearings run smoother and with less drag. The front hub has aluminum end caps with a carbon-fiber center, and the rear hub is all aluminum with a grease port covered by a carbon-fiber cap. The pawl mechanism for the cassette body ratchets on a titanium ratchet ring.
The front wheel is laced radially using 18 Sapim CX-Ray bladed spokes, while the rear wheel has 24 spokes laced in a two-cross pattern on both sides. The spokes are threaded to aluminum nipples. The two-cross lacing pattern on the rear was used to stiffen up the rear wheel so that no power would be lost to wheel flex, as a result more power is channeled to driving the bike forward.
The rear wheel is available to fit Campagnolo or Shimano/SRAM cassettes and the freehub bodies are easy to swap out with two 5mm hex keys. The set comes with valve extenders and HED titanium skewers. Any carbon-specific brake pad should work well with HED's braking track. The recommended rider weight limit for the HED Stinger 7 FR Carbon Tubular Wheelset is 210lbs.