l got told today by a staff at Evans bicycle shop that you can take the length of your heel to crotch in inches and minus 13″, and that will be the frame size you need. my heel to crotch is ~29.5″ so assume a 17″ frame would be most suitable? that corresponds to a Medium in cannondale MTB range l was told, l am ~ the minimum height for it. l saw one with 29″ wheels and it did look a bit on high side. would the Small be more suitable? because there l would be ~ the maximum height for it , but would be safer to control l assume. l long time ago l had a stumpjumper 15.5″ and it was a perfect fit opinions?
If in doubt, the best option is to always test it out… Have you checked out other bike stores in the area? No one stocking it? If you give them a call & tell them you intend to purchase it but would like to size it up first I’d have thought they’d probably get one in the shop for you.