Can I buy it?
No, there is only one prototype in existence so far.
Is it possible to use it with a Derailleur rear cassette on the back wheel?
No, but here is the point. Yes, there are cyclists who use 28-21-14 speeds, But the fact
of the matter is that the vast majority of riders don't. They use 4-5-7 of their favorite gears only during the bicycle ride. And my humble opinion is that, if the elderly walk faster uphill on the sidewalk than
you ride your bike, then probably you have a lot of unnecessary gears.
How much will it cost?
I don't know yet. It depends of a lot of factors, but I don't think it will be expensive.
Can it have more speed?
Yes, I'm working on a seven speed version right now.
What is the overall gear range?
I'm constantly testing different gear combinations, so far my preference is equivalent to a 48t front ring matched to a 17-26t six/seven speed cassette, but that can be adjusted up or down. (go up to 28, or down to 16 for example).
How heavy it is?
The prototype (the transmission itself) is 1200g.
During the development the weight was not the first priority.
The most important thing was to prove the concept.
On other hand, this design eliminates the rear cassette (approximately 500 gram/varies)
and the three front chain ring set (approximately 450 gram/not aluminum)
Any idea how long the battery will last between charges/replacement?
I was able to ride the bike for three days without recharging the batteries, and I changed gears many times, but keep in mind this is only a proof of concept prototype.
Can you give more technical data?
Only the potential partner, investor, buyer will get that information.
I have a phone holder on my handle bar. Can I use my IPhone or Android as
a remote controller?
Yes, I'm sure there will be an option for that.