hi i have a norco yorkville with a milk boxe carrier behing my seat . My regular kick stand always ply and break.
Also , with a single wheel trailer, the bike wants to flip on the side.

I search or a stand strong! that fit on this bike any suggestions?

Use a strap tohold the front wheel to the down tube. Look for a center stand that has two stands together.

Yup, a center stand might well do the trick. https://www.amazon.com/BV-Kickstand-Center-Mount-Bicycle/dp/B00LNLXML4/ref=pd_bxgy_200_3/132-1193804-3663914?_encoding=UTF8&pd_rd_i=B00LNLXML4&pd_rd_r=5e2eea27-108a-45be-9959-1ec3096f9e77&pd_rd_w=0LZGc&pd_rd_wg=gPQwI&pf_rd_p=a2006322-0bc0-4db9-a08e-d168c18ce6f0&pf_rd_r=4B99VF7NMHDDVPECYSSZ&psc=1&refRID=4B99VF7NMHDDVPECYSSZ

Though I would find one that isn't adjustable length. That sort of stuff compromises strength, and in my experience, doesn't generally hold up to the needs of touring.

HI i tried to install a 2 branches stand in the middle but with my bike step through, the cable for shifting pedal plateau passes through the spot as you can see on the pic (i hope now i can post picture!) the metal rectangle slided into the cable ...
ideas how to solve?

on www cijoint c/ IGEwsfOhOfn
can you see it

No picture. I think you need 10 posts. There is a way to solve it, but you're correct that a picture would be very helpful.

ok i try again

ok ill try to post i again

Can you turn the bike over and get a picture of that from the bottom, and not quite so close? I'm curious what kind of guide you have under the bottom bracket, and how much space you're working with.