Double to single axle tongue weight ?

a test drive is by far the best way to know .
tongue weight and the distance from coupler to the trailer axle is a critical dimension on a single axle trailer .
There are some very good handling single axle trailers .
They tend to have a Longer coupler to axle length .
They tend to have more tongue weight .
Consider which handles better .
A trailer with the wheels at the far back end .
Or a trailer with the wheels close to the coupler .
An exaggeration of course , but now you get the concept .
Use the State Of Oregon scales when closed to weigh your prospective set up on every axle including the tow vehicle .
Weigh your old setup the same way .
Weigh your tow rig the same way .
This will help you figure if the new single axle trailer will be a good handling setup .
Boat trailers handle great because the wheels are set back further than a TT .
That is because boats tend to be stern heavy .
Boat trailers adjusted to move the axle back another foot from the factory setup handle exceptionally well .