Tandem Titanate 2WD.
My first build, took forever, many hiccups. Used Shengquan 10ah LTO cells, 29s 2p, approx 70v. Should last last my lifetime if cycle life is anywhere near what they claim.
It was always going to be a non- practical build, doesn't look anything like road legal, especially in nanny state Australia. I used a tandem frame to allow room for the big batteries, also to have more rider weight on front wheel so 2wd has good front wheel traction. Used Grin hubmotors and controllers. Power is 70v x 40amps to each wheel, so around 5600 watts all up, don't think a 250w sticker will fool anyone.
Exhilarating to ride, acceleration is incredible, I was worried I would be disappointed but in the end it was better than I imagined. Big LTO's hardly break a sweat, so far they haven't gone above about 22 degrees C, although it is winter here. It rides well on good tarmac, but really needs some suspension for rougher roads. Not sure of top speed but gets over 70km/h comfortably, not keen on going any faster than that, it's the acceleration that is addictive. Hub motors are running cool, they are vented and painted black inside, haven't gone over about 29 degrees C, although if I run only one motor the motor gets over 40 degrees C easily. Will be interesting in summer what temps I get.
I chose LTO chemistry because I just was not confident using Lithium ion for my first build, worried I would burn down my house with my inexperience. I know I could make a pack half the size, but really wanted something safe & love the idea of a battery that will possibly last decades. I was tempted to go with Headway Lifepo4's, but really when I did the sums for my power and watt/hour goals, there was not a big difference in size and weight, and the LTO's would stay strong for so much longer.
Overall learnt heaps, got so much help from forum members, Sunder helped heaps in the early stages, thanks Mate, and a number of guys helped save my sanity when I could not get the 2wd to work properly, as seen in this thread,