I've used bias car tires, radial car tire, bias trailer tires and radial trailer tires over the years on different trailers. Radials always swayed more than bias tires. Sometimes it didn't show as a problem until the tongue weight changed from improper boat loading or in extreme gusty winds...or when a big rig buffeted us hard. One time I replaced worn bias tires with radials on a 20' boat where the trailer capacity was near max. It didn't sway at all with bias tires but swayed so bad with the radials I took them off after the first road trip and replaced with bias again. No radials on trailers for me. Bill P. ************************************** See what's free at http://www.aol.com.