I had the chance to mount and measure the tire today as compared to a well used Conti GP4000s. Both are mounted on my light-bicycle u45 rims which have similar internal and external dimensions as the firecrest 303.

Sorry for the bad pics. Digital caliper batteries were dying at the time of the pics. Stated measurements were done with a fresh battery.

Conti Gp4000s measures 25.2mm width on the rim. No doubt it has stretched.


We all know Conti's are tall. Here it is on my S5 - very little room in the cutout.


Here is the 23c Zipp Tangente Speed clincher. It measures 23.2mm On this same rim the 22c Continental Attack measures 23.4mm. From memory, these are very similar in dimensions to the Vittoria Triathlon Evos I tried out awhile back.


Here is the wheel cutout with the Zipp - much more room.


Lastly, bike pic - the white zipp logos are prominent.