Hi There,
You can rent scooters from the centre of Hisaronu, from £8.oo a day, ( the twist and go kind ), you need to take your licence and have it with you all the time you are riding or driving in Turkey.
Take your time there, suggest you try to find your way to kaya koy, only about 3 mile from Hisaronu, have a good look around then maybe you can carry on down to gemeler beach. don't think i've seen any mountain bikes for hire.
Kev

We didnt find any mountain bikes for hire but Sky Sports used to do mountain bike trips from Hisaronu down through Kaya Koy to Gemiler beach with a landrover ride back. Stopping to sample local fruits and wine etc with the friendly guide, Jordan, made it one of the best trips of our holiday. If they are still doing them you will see the bikes on a trailer parked at the garage in Hisaronu. You book at their office in Olu Deniz or Hisaronu.