I just installed one of these on my husband's Specialized Diverge as a Father's Day present, since he doesn't want to get an ebike, but as he gets older is having more difficulty climbing hills which means that he doesn't ride as much as he would like. You can't really install a lot else on the Diverge since it's a thru axle carbon frame with a non-standard BB. Maybe a Grin Allaxle but that's about it. And I figured the Qiroll was a low enough investment where if it didn't work, I could sell it and not be out a huge amount of money.
I got the standard Qiroll (not the Pro version) so I had no choice but to install it on the chainstay with the included adapter. None of the included machine screws were long enough, but a trip to the hardware store for 2.5 inch machine screws did the trick. Installing it on the chainstay doesn't leave a whole lot of extra tire clearance, so we wouldn't be able to run wider tires with this setup, but since hubby likes thinner road/touring tires (25mm Schwalbe Marathons), and rides on pavement instead of dirt/gravel it worked out ok. In retrospect the Pro version might have worked better because then we could have installed it on top of the seat stay and thus maintained tire clearance, but I also like that it's more inconspicuous down below the bottom bracket.
https://photos.google.com/photo/AF1QipMlSjkeC-gY1D-dZqVaPaZX9btb-XJz3F0nJdoK
I had to experiment to get optimal pressure on the tire so that it either doesn't slip or has too much rolling resistance to work properly, but once I got it right it seems to work well. The 1 mile hill to our house ranges between 8%-16% grade (fortunately most of it is closer to the lower end) and surprisingly I'm able to climb it with this motor (I can't without assistance - the only people who cycle up our hill are people on ebikes or elite riders training for races). My own bike is equipped with a 250W ebikemotion X35 so I'm used to climbing with a lower power pedelec.
Things to keep in mind with this little unit are (1) your bike has to have the gearing and such to handle whatever terrain you want to climb, even if you need the extra assistance to do so and (2) you have to help, sometimes a lot. And (3) don't have unrealistic expectations - it's not the same as having an hub or mid-drive motor. Also, it really doesn't like wet dirt - paved surfaces only, or if you're on any dirt at all, it needs to be bone dry or else it will slip (most of the road going up to our house is paved, other than the last 2/10 of a mile beyond the crest of the hill - fortunately, by that point we don't need the motor anymore).
Kouzou - are you still having problems with yours? It looks almost like the three allen screws that position the motor into place aren't tightened all the way causing it to swing up when you actuate the throttle.