Hi, I dont know if the same rules apply over there in the States, but the rules are very clear here in the U/K they are as follows :
In the UK in 1984 it became legal to tow a trailer behind a motorcycle. The rules governing the use of trailers behind motorcycles is set out in the Road Vehicles (Construction and Use) Regulations 1986. As far as motorcycle trailers towed behind a motorcycle are concerned the law is basically:-
The towing motorcycle must exceed 125 cc engine capacity.
The trailer has an overall width not exceeding 1.00m
The distance between the rear axle of the motorcycle and the rearmost part of the trailer must not exceed 2.5m.
The Motorcycle must be clearly and indelibly marked with it’s kerbside weight.
The Maximum towed weight, including the trailer and it’s load must not exceed 150 Kg (330 lb) or two thirds of the motorcycles kerbside weight, whichever is the least.
The UK speed limit is 60 mph on Motorways and dual carriageways and 50 mph on all other roads unless a lesser limit is in force.
For sure the Busa got the power to pull, but stopping and turning in a hurry!! The thought of that load behind you jack knifeing = scarey
Hope this helps Stay safe