Installing a tail Trunk on My Ducati ST4s

I bought my Ducati used in 2010. I had a trunk from my last bike that the person I sold the bike to did not want, so I kept it.
I tried to find a mount for the trunk. but Ducati does not make one any more, and neither does Givi.

I found a fabrication shop and took my bike out there, but they said $300 to $600 to make it depending on how much time it took them.
I figured I could do a good job myself so I took on the project.

I started out wanting to use some 1/2" 1/16th wall tubing, but could not find anyone who could bend it for me. I finally found a shop who would do the work, but I had to step up to 3/4" tubing. That was fine, but then the only tube I could get was 3/4' DOM 1/8" wall. I dare say the rack tubes are thicker than the main frame tubes.

I had to cut the under seat shield holes bigger so the trunk mount would fit at the same time as the mounts for the side bags.
The mounts for the side bags have ridges stamped in them, so I had to bend the mounts I made to clear them
Here is the rear mount. About 2 3/4" long.
The front gets a double bent to keep the tubing down to one bend. These are 3 1/4"
I used copper tubing to make a pattern because I could bend it.
Here is the first mock up.
And with the Givi mount on it.
Here are the tubes all clamped up and ready to weld.
I pulled the battery AND the ECU. I already had to buy one ECU for this, don't want to do it again.
No more in process pics.
After I had it welded up, I sent it out to be powder coated, time to mount it now.
The tabs for the trunk mount go inside of the mounts for the side bags.
And another shot of how these bolt up.
I did have my son hold the mount so I could get the rack started. Not sure if I could have done it without the extra pair of hands or not, but it was nice to have them.
Here is the rack with the plastic and seat back on. Time to mount the trunk to it.
The powder coat shop said to tape the powder coat so I don't scratch it while drilling the holes.
I drilled holes in this cross piece for the rear bolts on the Givi platform. I used the Givi clamps for the front mount.
Doing this part I saw that I was not perfect in lining everything up when I welded this. I lined the platform up with the bike and center-punched where the holes went and drilled them. When the holes were drilled you could see that this piece was not perfectly squre to the bike.
And the trunk mounted up!
But I did get the trunk mounted on the bike straight.
It is a close fit to be able to remove the taillight lens, but it does come off without removing the rack.
And with the side bags.
My son and I on the bike showing how everything fits.
My son leaning against the trunk (I am sure that with the size of everything it will have no issues serving as a backrest..
The other thing I was concerned about was allowing room for the key to remove the seat, as you can see it still fits.
I think the thing came out great. Is it as perfect as a factory one? No. But you have to really look to see the flaws (Not perfect at the back. Some weld splatter, all of which is covered by either plastic or the trunk mount).
I am more than happy with how this went. I am glad I took it on. Now I have all the room I need for road trips on this thing.

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