Hi Hugh - This particular base layer doesn't have a cycle specific tail. It is designed to have a close to body fit and is light enough to be worn underneath your regular cycle top. I'm sure you'll find it has enough length to be tucked into your cycle shorts if you don't want your lower back to be exposed. Keep your eyes out though cause I know Orca is currently developing a cycle specific merino range. Based on your dimensions I would suggest an XL. Hope it helps.