Dual hitch adapter.. De-rating when extending hitch.

What you’re proposing will be just fine weight wise. Assuming you are talking an actual double stinger truss type hitch and not some bolt on **** to add a bike rack.
But how many years we goin on now without that mythical “perfect” trailer/camper?

I'd upgrade to a Torklift SUperhitch, which is a dual receiver hitch, if I were going to be towing AND hauling my DRZ on a hitch rack.

Or buy a Geo Pro toy hauler.

Could you per chance modify the hitch to work better for what you want? Like instead of 1 hole, have 3? Use the 2 outside to haul the bike, higher than hitch would hold it. Be much more stable than holding 300 pounds on 1 point with the extra lever to get above tongue.
Then instead of using a extended ball mount, extend the tongue of trailer.

^Don’t worry about it.
There is so much wrong with that scenario and based on the posters history, no action plan anyways. Not the least of which being the “may need 12” extension” to get past a bike rack that is 31” long plus some extra handlebar length. It would be silly with just a typical dirt bike hitch rail but at least it would be shorter than the contraption posted.
Tried to help him years ago with trailer selection and realized there’s no use.

Grit dog wrote:

Tried to help him years ago with trailer selection and realized there’s no use.

So why try again and then belittle me? I'm trying to motivate myself to spend money to become homeless, and get your attitude again. Run along now dog..

To the rest of you.. Thanks.. Sounds like the receiver will hold, but I still don't know how much you re rate a receiver when you start to extend the hitch..

Do you know the manufacture of the hitch if so, contact them. Tork lift in Kent Washington has/had a few setups as you describe. They included a deduct for extended ball mounts.
If your near here, easy to get. If not, email, ask if they can do a hitch as scooby described. Easy to put on a pallet, ship to you ready to bolt onto your truck. Or in multiple pieces, assemble them one at a time.

On edit
Their are probably dozen places or more in Puget sound where I am that can custom build hitches to do as the customer wishes. Looks like you are in the Midwest. I would wager a small sum that you are at max, a days drive from an equal body bed hitch manufacturer. They can and will build a hitch to your specs. Not just a generic number.

Marty

Just curious why the bike doesn't go in the bed of the truck? It's not that big or heavy, seems easy to get into the bed and strap down and still give you plenty of other space to store stuff.

Doing more thinking. I know my ideas may not be good, but thinking about bad ideas have produced good ones.
The fact OP wants to haul outside bed implies some weight in bed. Then TW will transfer some weight from front to rear axle, plus more than TW to rear axle.
On any truck, the axle least likely to be overloaded is front.
If going to build custom hitch, build it to mount on front. Still need 2 point mount*, but that extra 400-500 lbs will not be messing with trailer.

Do you need to mount at 2 places? To slide into the receiver, you need play on side and top. Call it 1/16 inch. (Likely more) How far above the tire rail is SOG of bike? Plus rail will be above mount. I'm betting that SOG will be couple feet from mount. So that SOG will move well over inch. With inch stroke, a 300lb hammer can deliver a bell of a wallop. And there will be a lot of wallops per mile.

"Run along now dog.." I'm still laughing. I've blocked said Dog so many times but I guess I'm addicted and unblock him after a day or two.
He or she is a cranky old soul but says what others are thinking and as such is a valuable member on this forum.

spoon059 wrote:
Just curious why the bike doesn't go in the bed of the truck? It's not that big or heavy, seems easy to get into the bed and strap down and still give you plenty of other space to store stuff.

Yep, when things go "rube goldberg", look at different alternatives.

A couple more far simpler alternatives:
- Get a front mount hitch & rack to put the bike on the front of truck.
- Get a welding shop to cut off the A-frame off the trailer and build a new one that is maybe 3ft longer with a platform for the bike.