Hi,
Apparently E-bikes are a lot more fun using the assist setting.
Why not ? Could work. In the UK the assist is supposed to shut
off at 15mph (also max speed unassisted). That could be a
problem if you generally like tanking along at 18 mph.
Though you can illegally modify E-bikes to go faster with less
assist, i.e.change the gearing on some, depends on the details.
TBH the chances of being done for riding a E-bike modified to
keep up with a road bike are pretty small, but the type of
E-bike and what you want it to do needs researching.
Basic information given tends to be paltry.
rgds, sreten.
Your butt will be severely kicked going up hills
UK E-bikes are not fast, except for going up hills ....