Burden with riding gear (6)
I believe the answer is:
saddle
'burden' is the definition.
(synonyms)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for saddle that I've seen before include "Seat for a rider, horse or bike" , "Equestrian seat" , "Seat for a rider, horse or bicycle" , "Rider's seat" , "Encumber" .)