1972 Trillium 13’ - looking for tire advice:)

[Barb in North Van]

Hi Trillium owners,
Looking to replace the tires on our 1972 Trillium 13’ trailer.
Currently - P155/80 R13
Someone mentioned that I might be able to to to 14” or even 15” to help with bumpy roads...
Any advice?
Thanks,
Barb from North Van, BC

[David Tilston]

For my Trilliums, I use ST205/75R14 tires on Ford Ranger rims. Had to grind out the center hole a bit though. I think 15" tires might be a bit too big though.