I'm traveling to Puerto Vallarta, Mexico soon and I'd like to do some mountain biking while I'm there. I've heard the country side is quite beautiful there. I would like to avoid being alone so if there are; perhaps, guides or group adventures, that would be a place.
I was in Puerto Vallarta last week, and did some asking around, but with very little success. Cycling doesn't seem to be popular there. The closest I found was some motorcycle and 4-wheeler rental places. I know it's not quite the same experience, but at least you could be "out in nature" on some wheels...
Also, in my experience in other parts of Mexico, mountain biking just isn't popular. Hiking is, to a degree, and cross-country biking. But I've never seen or heard of mountain biking, per se. And I've never seen any trails suitable for mountain biking (but maybe they're kept at great distance from the hiking trails where I've been... shrug)
Here are a couple places I found:
Harley Davidson Rentals
Cool Rentals & Cool Tours
Avenida México is the main street that runs one-way north to south through the main part of Puerto Vallarta, so both of these places should be easy to find.
They were both closed when I went by, so I was not able to go in and ask for any details or prices. Likewise, I cannot make any actual recommendations.
I hope this is of some use to you, even though it's not related to bicycles directly.
Have fun in Puerto Vallarta!
I definitely would recommend going with a group. I don't think mountain biking is that big in Mexico but you might want to check with the hotel you're staying.