Most assuredly part of it, is break in. You can feel it in the seat of your pants when they settle in. Ya feel a boost in power and get a lil more speed. Kinda a high.
But truth be told these poor lil things are supposed to go about 20/22 MPH. The vibes and struggling above that is mostly due to basicly redlining em.
Can't see in your picture but how solid is the front mount? I would look and ask in the stretch section. http://motorbicycling.com/forumdisplay.php?f=40
Could be lots I dunno about but will be old hat to the folks that build and ride em regularly.
I have been playing with motorized bicycles for, dunno 10 yrs and learn some thing new almost every week. LOL, some times relearn. Just sayin get lots of thoughts so you can find what works best for you.
OH! be sure to check out events section! motorized bicycle folks are half a bubble off plumb but to the good side of the high side. Seriously, great fun. Until they "invent" something and wanna sell it.
But great and I mean great learning experience attending a group ride.
I host one in Hartford in the spring most years.
Never be worried about asking questions. It is actually against the rules here to be less than kind to fellow members and there are ton of great and knowledgeable people eager to help.
LOL, to much coffee. Sorry about the wall of text, Sam.....