Flew into Montego Bay on 11/29, drove over the hills to Whitehouse on the other side of the island for a week at Sandal's resort.....I would not take a bike, nor would I ride the highways.....no shoulders whatsoever, traffic is very agressive, roads are very bumpy, lots of crumbling pavement, blind curves, lanes are very thin.....remember traffic flow in Jamaica is to the left as in Great Britain, not to the right....
Several years ago, stayed in Negril....roads close to Negril are rideable, but I would not plan on venturing very far from there...maybe 2-3 miles at best....
I think nothing of commuting 3,000 miles/yr in Fort Myers/Cape Coral with massive snowbird traffic this time of year.....Many years ago, I commuted for 3 years in downtown LA......I would not ride on Jamaican highways...
For your first trip, I would rent locally....if you are staying at a resort, call or email and ask their opinion....
We loved our week at the resort...people & service was spectacular....the only thing I missed was my daily commute ride.....but I would not ride there...