I am running a danmoto can and I had to push mine away from the back peg and use spacers to keep it there and mine hasn't broken yet. Ill be fixing it when I put my headers on it

 

I saw this thread and thought I'd share... Purchased and installed back in April on my F2... Did not have one issue, maybe they have changed/upgraded the clamps and springs...

 

I'll re-post after buying a GP Megaphone style and running it for a while. I had no issues with fit or durability. I ran mine for a month or so and I liked it at the track, for sure...For the street? Too loud for me. No matter how softly I wound the throttle I could see frowns on people as I rode past, heads turning, etc. Now I know how loud Harley riders must feel as they ride their noise-makers.
I found myself riding 'around' the noise....keeping the revs down all the time, running in too low a gear, etc. I swapped back to my Jardine shortened can and ride with more pleasure now, though the Danmoto certainly looks a lot better and is probably a little lighter...just too loud for me.