i think your getting gross VEHICLE weight rating vs gross COMBINED weight rating is two different things
CDL requirements BEGIN at 26,001 lbs but gross vehicle weight rating (GVWR) on the trailer will determine whether you need a Class A or Class B CDL. The GVWR of the trailer must be 10,001 lbs or more to fall under Class A CDL.
Example 1: Truck GVWR 11,000 lbs. + Trailer GVWR 13,000 lbs. = GCWR 24,000 lbs. - NO CDL required
Example 2 : Truck GVWR 11,000 lbs. + Trailer GVWR 15,500 lbs. = GCWR 26,500 lbs. - Class A CDL required
Example 3: Straight Truck GVWR 28,000 lbs. = GCWR 28,000 lbs. - Class B CDL required
or
Example 1: (truck)GVWR 11,000 lbs. + (trailer)GVWR 9,800 lbs. = GCWR 20,800 lbs. NO CDL required {11,000 + 9,800 = 20,800 lbs}
Example 2 : (truck) GVWR 11,000 lbs. + (trailer) GVWR 15,001 lbs. = GCWR 26,001 lbs. Class A CDL required {11,000 + 15,001 = 26,001 lbs.}
Example 3
truck) GVWR 17,000 lbs. + (trailer) GVWR 10,000 lbs. = GCWR 27,000 lbs. NO CDL required {17,000 + 10,000 = 27,000 lbs}
(The GCWR is over 26,000 lbs., but the trailer is under 10,001 lbs.)
Important number to watch is the number 1 at the end 10,001 lbs & 26,001 lbs. That 1 lb makes all the difference.
GCWR : Gross Combination Weight Rating (truck + trailer)
hope that clears things up