Joined: Jan 2009
Posts: 44,345
Likes: 6,643
From: New York, NY, and High Falls, NY, USA
Bikes: 1962 Rudge Sports, 1971 Raleigh Super Course, 1971 Raleigh Pro Track, 1974 Raleigh International, 1975 Viscount Fixie, 1982 McLean, 1996 Lemond (Ti), 2002 Burley Zydeco tandem
No, you don't need heavier spokes. You need to build your wheel with adequate tension and even tension. 14 gauge spokes are fine for your load. Also, the trailer should not be a factor in these troubles.