Is Trek/Bontrager the only company that has overlap in their sizes? 2 cm of overlap to be exact. Seems to make good sense, considering there is more than just circumference to take into account when fitting a helmet. I’m particular about bike helmets and usually try several before settling on one. Last go around, after trying Giro, Specialized, and Bell (road helmets in this case), I settled on a Trek/Bontrager Circuit. Not the fanciest, or most expensive, but it felt right. I actually had my eye set on some others. I’m not sure if these are rebranded from another source, but while shopping for a new aero lid something occurred to me. With all of the marketing about new fit systems and better adjustment (Roc loc version x, super fit, etc), why not have just a little size overlap as well? Maybe it would impact too few in the market, but as someone who seems to always sit at that magic point between sizes (upper limit of one size, lower limit of other), I appreciate that extra flexibility. Instead of picking a helmet that is only a click away from being too small, or a click away from being too big, it’s nice to know that I have two options, both of which give a little more flexibility, and can take into account other factors besides just circumference (how high the helmet sits, width of profile of helmet, sunglasses fitting, etc) - and esp. in our mail order world where sometimes you can’t just try one on. Just thinking.
For example. Trek offers sizes (S 52-56, M 54-60, L 58-64)
as opposed to
Bell / LG (S 52-56, M 56-59, 59 -62)
Giro (S 51-55, M 55-59, 59-63)
I have no affiliation with Trek BTW.