Actually there's one outfit that specializes in kits for fast electric road bikes, Calibike*
The improperly laced spokes on my Juiced CCS wore out the spoke bores,
The motor still worked but began to butcher spokes on every ride. I bought a Calibike
kit for $250 that came with everything but cutoff brake levers. As luck would have
it, I all i needed to do was plug in the wheel to my existing setup. It was a much
superior wheel with stronger spokes. They also sell very reasonable battery packs,
but i used what I already had. For a bit more money, I could have bought a kit that
turns a road bike into a 40 mph monster, Kits are simple to install & that wheel &
motor has out lived the Juiced CCS,(now a parts bike)
Since then, I purchased a NCM Moscow e- mtn bike that is far better for 1/2 the
price. In spite of the name, it's made in Germany. I guess the idea was to market
it in Russia. Anyway, just because of the name, they haven't sold well here.
They are presently going dirt cheap for $1059, absolutely the most bike you can
buy for the price. I paid $1300, still a bargain. It arrived from LeoncycleUS in
Seattle the day after I ordered it. (I live on the 'other' side of Puget Sound).
This bike will climb a tree.
The Germans are
finicky about engineering & use, be sure to read the manual carefully if you buy.
At this price there's plenty of wiggle room to personalize the bike.( see the EBR
review for spec, etc)