Hire bikes in South Mexico
 

I'm flying to the Yucatan area in January for 3 weeks and was hoping to hire a bike when I get there. Is there any reputable companies i can get in touch with? A 4 cyl, 600cc Japanese road bike was what I had in mind, but would take anything.
Also is possible to get across borders with a hire bike? I'd like to venture into Guatemala and Belize if I can.
Any help much appreciated!