For sale here is this pair of Rapha 3/4 shorts in new with tags condition in a size 30" waist. They are quite slim fitting, so I would say they are at the smaller end of a 30" and for an average thigh circumference.
RAPHA Brevet Bib Shorts, Size L =34"/36" waist
Mens Padded Cycling Liner Shorts Under-Shorts Lightweight Sz 34 Black X2 VGC
Rapha Mechanics Trousers. Cotton. 34” Waist. Slim Fit. Black. Brand New with tag
Rapha Índigo Denim Jeans. Standard Fit. 30”W, 32”leg.
Rapha Cotton Cycling Trousers - Size 30/32. Grey. Excellent.
Rapha Women’s Jeans. Blue / Grey Colour. Size 12 R. Waist 30” Leg 29”.
