capacity of a stock Casita
17' is 3500 pounds, and the maximum capacity of an ST205/75R14 is 1760 pounds... just barely adequate to use the full capacity of the axle
, which is why this is the size commonly provided by trailer manufacturers with this common axle capacity.
If the trailer is loaded near the limit of the 3500 pound capacity axle, and especially if it is unevenly loaded side-to-side, there is little if any tire capacity margin. Thus, the interest in additional tire capacity by Casita
17' owners. According to their website, Casita now equips the 16' and 17' models with 15" tires
(of an unspecified size).
On the other hand, none the Casitas which Frederick has weighed and reported in http://www.fiberglassrv.com/forums/f...rld-43010.html
even get close to the 3500 pound axle limit, so for those owners there should be no problem with tire capacity.
An ST215/75R14 Load Range C has a maximum capacity of 1870 pounds (as mentioned above)... higher, but only 110 pounds per tire higher.