I've written to several bike stores visited a few like decathlon and world of bikes  and checked Lazada Shoppee etc and they've all said hell no, and hell no to ordering. 

So can anyone suggest a thai cycling site or store that might offer " western size "  XL cycling helmets for me and my apparently massive 64cm  head? 

My only option at the moment seems to be Amazon where the cost of shipping and no doubt duties will be more than the cost of the helmet. 

There are apparently no standards at all for S,M,L, XL but I mean the Amazon definition of XL  below.  They also sell XXL but couldnt find a definition.

 

Amazon Sizing                                      
Small          51-57                                                     
Medium     54-60                                                             
Large         58-63                                                              
X-Large     60-66

XXL             Brain the size of a planet 

 

Typical Lazada sizing -

Any colour or design you want - One size definitely fits all ! or

S:  52-56 cm

M: 55 - 57 cm

L: 57 - 59 cm 

XL: 59 - 62 cm.

 

https://thai.webike.net/

I would write a stern letter of protest to the Decathlon world management,  in France.

 

Decathlon , 4 boulevard de Mons, 59650 Villeneuve d'Ascq, France

 

aliexpress? 

 

GUB 282g Ultralight Helmet Cycling Mtb XXL 61-65cm Road Bicycle Helmet

https://www.aliexpress.com/item/1005004997212652.html

Order from Specialized.

Decathlon helmet Sizing for adults: 

59-62cm = L

 

There are 'some' helmets sold by Decathlon Thailand that come in XL size.