I did the Iguana Mama 1/2 day "El Choco Loco" bike tour this May. Basically you show up at 8am. My wing and I took a guagua (mini bus/car) across from the Texaco station from Sosua to Cabarete. Maybe 30p or something cheap like that if I remember. Took about 20min. We just told the driver "Igauna Mama's" por favor. It's right on the main drag in Cabarete and they drive right by it.
Met up with our guide at 8, a young dude around 20 years old who spoke great english. There were just two of us and the guide. The bikes are 29r Fuji's in pretty good shape, they include helmets. It's about a 44km ride or more with most of it up a gravel/rock road over couple low mountains in the countryside. There are a lot of hills. I mean, the hills never friggen ended, (up hill both ways!!!) We had to walk up a dozen of so of them. There is lot of washed out rocks so this could be a really bad deal if you wiped out. The guide stops a few times at some c-stores/mercado's for drinks and rest. There is also probably about 10km of asphalt on this ride also getting too and from the road.
I would not recommend this for someone who has never mountain biked before, unless they are pretty daring. It's some really serious cardio and leg work and figure a full 4 hours. I would not recommend this after an all nighter and you really need to be somewhat fit. It was a good time though and a great work out. The scenery was pretty cool. The guide was a great dude.
We had mountain biking shorts with us, but could have used more pads. Also, If you are into mountain biking, I would consider bringing your body armor with you at least for your knees and elbows.
http://www.iguanamama.com/el-choco-loco-44km.html
