[bowmanx4587]

As seen on my 23 1100, they added a damn riser to prevent slip on exhausts. It's welded on, no way to remove. Is this the case for everyone else that can answer?

 

[zecer]

Hmm... I have a 2021 Rebel 1100, and I as far as I remember I had similar gasket (riser) at the end of the pipe. But I was able to remove it quite easily. Behind the gasket there is a "collar" which is welded in place and painted black. You can see it on your photo.
Moreover you can check the video of QuasiMotard:

about removing the OEM exhaust.
Maybe it is stuck due to the heat of pipes?

 

[Garster Red Rebel]

I had a little trouble lining up hangers on the rear but, after loosening up the mid-pipe I wedged the handle of my hammer it was soft rubber and wiggled it until I could slip the bolt in easily worked out fine for installing the Vance and Hines slip on very happy with the results.

 

[rws]

the exhaust gasket indicated by red arrow can be removed fairly easily

the collar indicated by blue arrow is welded on

remove the gasket

any slip on listed to fit the 1100 should "slip" on