I have been doing a bit of reading up on this and some people have had problems with certain tires on crests, makes sense really the crest is about 6mm wider that some 700c rims. In turn its only a little wider than stans own iron cross rim.
The other thing is that if you are running tubed roadie tires and were trying to get near maximum pressure I don’t think the crest is rated high enough as they are meant to be used with bigger low pressure tires.