questo è riportato sul sito Zipp.
"Product note:
The wide profile of the 303 Firecrest is crucial to Zipps revolutionary Firecrest technology used to create wheels with superior aerodynamics as well as improved stability and handling.
The rear 303 Firecrest, however, may present some fitment issues for a small number of road and triathlon frames. The clearance between the chainstay and the rim may not be adequate to avoid contact between each other when ridden under load.
We urge customers who plan on riding the 303 Firecrest to test the wheel within the frame in which they intend to ride it, under normal riding and road conditions, before purchasing. Clearance within individual frames of the same size, from the same manufacturer, may vary. That is why it is imperative that you test the wheel in your frame, or in the frame that you are considering purchasing.
Customers who run into this fitment issue may select any other spoked wheel within the Zipp lineup as an alternative,including the 404 Firecrest with its narrower aero-width profile.
Below is a list of known frames that may present this issue. This list will be updated if this fitment issue is discovered elsewhere.
Specialized Tarmac SL4
Specialized S-Works McLaren Venge"
Riassunto veloce, visto che il profilo della 303 è molto accentuato, ci potrebbero essere problemi con un numero limitato di bici , in questo caso si può ripiegare sulla 404.
Sotto riportiamo l'elenco dei modelli in questione...