Ah yes I do know them of course…funny store…literally EACH time I visited them they told me about something which is in fact not existent… 
…and for HP: Yes, I had (enough).
Strida hidden power electric Kit
I was referring to E Strida - the genuine electric one by Ming
Edit: Btw, the most sophisticated solution for my meaning comes from Russia:
Strida electric drive by Aleksandr Mironov
https://www.youtube.com/watch?v=kB8qpnzAvFE