I have both mountain and road. My first mt bike was a specialized rockhopper size 15 (or 15.5 I can't remember). It was too small so I sold it a year later. Now I have an old beater mt. bike size 16.5 and it fits me like a glove. My road bike is a Trek 1000 WSD size 51 cm and it fits me well. I am 5'5 with a 30 inch inseam (that was a fun measurement at the bike shop). I would think a 17 inch frame would be doable, you would just have to check it out to see.