06 sportster

i have a 2006 215 hp. was up at the lake this weekend and when it was time to come home realized one of my trailer tires has lots of movement. like an idiot i left the boat there without taking the bearings out to size them. can anyone tell me right off hand what size bearings i need to get to take back with me this coming weekend to fix the problem. any info would be appreciated. thankyou