I'm a freelance writer and yogi living in Tepoztlan, Mexico where I'm running www.casadelcorazon.mx with my girlfriend. You can keep up with my other writing on www.bollocks2thewellingtons.com/
Based near Wat Phra Singh on Samlan Road, this Western run outfit offers adventurous trips by mountain bike up into the hills (or down from them) and kayaking expeditions along the local rivers and lakes.
I haven't experienced the Mountain Biking but I understand you can do a trip where they drive you up and you come down under your own steam, which sounds like the best way to do mountain biking to me...!
I did do a day of Kayaking with them though and our guide Aidan was funny and helpful as he showed us the ropes and then gave instructions on how to negotiate the swift turns and currents of the narrow river.
They offer a variety of routes and they change depending on the season and water levels in the rivers but we took one of the beginners routes, I for one had never kayaked like this before.
We drove for about an hour to the dropping in point and then had a go each at paddling against the current, turning and "eddying out" where you pull up against the shore after or before a tricky manoeuvre.
We were warned that there would be some fast currents and we would need to paddle hard at some points and back paddle to direct the boat more easily. There were some sharp turns and parts where we needed to duck under branches and trees.
At first, I thought I was going to suck at it but I was surprised how quickly I picked it up and managed to get down the whole river without falling in. I would still expect to get rather wet though!