I just happen to think. I can tell you what I did to build the guard / highway bar if you want to recreate it.
For an easily removable bar (e.g. if you go on- / off- road a lot):
>> 1" dia. x 30" L black iron pipe (or whatever your pref. length is)
>> Threaded caps for the tube
>> Grade 8 bolts (at least 1.5" ~ I use 2") w/ matching lock washers & nylon nuts
>> These bar clamps:
https://www.amazon.com/dp/B01FETT3FO...v_ov_lig_dp_it
1) Mount bar clamps to the front part of your frame (behind the wheel at a safe ht for the bar).
2) Hold the pipe up to the clamps & mark where you should drill
3) Drill holes through your pipe (to provide holes to bolt your pipe to the clamps)
4) Attach the pipe to the clamps with the bolts
5) I use a little blue threadlocker to both my clamp bolts & red threadlocker to the pipe bolts to keep the bike vibrations from working them out. While I'm driving on the road, I figure I can tell if the pipe is working loose as I'd feel it under my feet, but I still check it periodically (e.g. fill ups) to make sure things stay tight.
For a "permanent" bar:
If you're worried about the pipe working loose, or you plan to use a shorter pipe (e.g. using it only as a guard instead of as also highway bars), or you just want more rigidity (e.g. more assurance it'll protect your engine / legs from crashes), you could use red threadlocker on the clamp bolts, as well as cold-welding (or spot welding) the clamps to the frame. Despite the mild concern for what would happen if my bar ever came off, it's no less worry than any OEM fitted guard I've had on other bikes that just "bolt on".
With a little ingenuity, you could theoretically make actual crash bars using this method as a base. I almost did that myself, but wanted to keep wt. to a minimum & keep the attaching / detaching process simple (as a more elaborate guard would need multiple clamp points).
I'll get pics when I can, but I hope this helps.