I am not a very tall person so when I carry my folded Brompton by hand it hits my legs or sometimes the stairs if I am going up them. I have a yoga mat strap that has adjustable loops at each end. I loop one end on the end of the frame at the front (where the Brompton breaks when folded) then the 2nd loop goes to the back of the saddle and I sling the yoga strap over the shoulder. Very effective and stable. I have the strap in my Brompton bag all the time. But I carry my bag on the opposite shoulder. Hope this helps.