Originally Posted by
WeightySteve
Older wheel designs (before the hed/Zipp instigated wide wheel trend) were designed around, and are fastest with, 19-50 mm tires. I wouldn't necessarily worry about that too much before you even have best times to try to beat though, and if mavic says a tire size works I'm confident it will be safe and go on ok. It just might (probably) won't be the fastest option.